A copper chelating agent suppresses carbonyl stress in diabetic rat lenses

To clarify whether transition metals are involved in carbonyl stress in diabetic tissues, we observed the effects of a metal chelating agent, trientine (TE) hydrochloride on the levels of methylglyoxal (MG), 3-deoxyglucosone (3-DG), advanced glycation end products, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and polyol pathway metabolites along with semicarbazide-sensitive amine oxidase (SSAO) enzyme activity in lenses from streptozotocin-induced diabetic rats. Lens MG and 3-DG levels were significantly higher in diabetic rats than nondiabetic controls, and TE significantly restored the increase of these compounds. Lens argpyrimidine was also increased in diabetic rats as compared with controls and was significantly reduced by TE. Lens SSAO activity and 8-OHdG were also significantly elevated in diabetic rats, and TE suppressed both of them, whereas TE showed no effect on the polyol pathway metabolites. The results indicate that transition metals play a significant role in the formation of MG and 3-DG via oxidative stress and SSAO activity.     

Prevalence of multiple micronutrient deficiencies amongst pregnant women in a rural area of Haryana

Deficiencies of micronutrients (zinc, iron, folic acid and iodine) during pregnancy are known causes of Low Birth Weight (LBW). Studies have documented status of one or two micronutrients amongst pregnant women (PW). However, no attempt has been made to concurrently assess the prevalence of multiple micronutrient deficiencies and the factors associated with them amongst PW.Objective: The present study was undertaken to assess the prevalence of multiple micronutrient deficiencies amongst PW in a rural area.Methods: A community based cross sectional survey was conducted in six villages of a rural area of district Faridabad in Haryana state, India during November 2000 and October 2001. All PW aged 18 years or more, with pregnancy duration of more than 28 weeks were enrolled. Data were collected on socio-economic status and other demographic parameters. Serum zinc, copper and magnesium levels were estimated by utilizing the Atomic absorption spectrophotometry (AAS); serum ferritin and folate was estimated by Enzyme Linked Immuno Sorbent Assay (ELISA) method and the Radio-lmmuno Assay (RIA) method, respectively and serum thyroid stimulating hormone (TSH) level was estimated by the Abbot AxSYM System. Serum zinc, copper, magnesium, ferritin, and folate levels less than 70.0 μg/dl, 80.0 μg/dl, 1.80 mg/dl, 15 ng/ml, and 3 ng/ml, respectively were considered as indicative of deficiency for respective micronutrients. The TSH levels of 4.670 and more indicated iodine deficiency status. Dietary intake of micronutrients was assessed utilizing 1-day 24-hour dietary recall methodology. Food consumption pattern was assessed utilizing the food frequency questionnaire methodology.Results: Nearly 73.5, 2.7, 43.6, 73.4, 26.3, and 6.4 percent PW were deficient in zinc, copper, magnesium, iron, folic acid and iodine, respectively. The highest concurrent prevalence of two, three, four and five micronutrient deficiency was of zinc and iron (54.9%); zinc, magnesium and iron (25.6%); zinc, magnesium, iron and folic acid (9.3%) and zinc, magnesium, iron, folic acid and iodine (0.8%), respectively. No pregnant woman was found to have concomitant deficiencies of all the six micronutrients. Dietary intake data revealed an inadequate nutrient intake. Over 19% PW were consuming less than 50% of the recommended calories. Similarly, 99, 86.2, 75.4, 23.6, 3.9 percent of the PW were consuming less than 50% of the recommended folic acid, zinc, iron, copper, and magnesium. The consumption of food groups rich in micronutrients (pulses, vegetables, fruits, nuts and oil seeds, animal foods) was infrequent. Univariate and Multivariate logistic regression analysis revealed that low dietary intake of nutrients, low frequency of consumption of food groups rich in micronutrients and increased reproductive cycles with short interpregnancy intervals were important factors leading to micronutrient deficiencies.Conclusion: There was a high prevalence of micronutrient deficiencies amongst the PW of the area, possibly due to the poor dietary intake of food and low frequency of consumption of food groups rich in micronutrients. The concurrent prevalence of two, three, four and five micronutrient deficiencies were common.     

Serum copper and zinc concentrations and their relation to superoxide dismutase in severe malnutrition

Serum Zn and Cu levels were measured by atomic absorption spectrophotometry in 117 children (aged 3 months to 5 years), divided into two groups; 80 children suffered from severe malnutrition and 37 children served as controls. Significantly lower levels of serum Zn and Cu were found in the malnutrition group. Zn levels of 2.59±0.15 µg/ml as compared to 3.92±0.35 µg/ml in the control group (P=0.0037) and Cu levels of 0.74±0.05 µg/ml in the malnutrition group as compared to 1.19±0.08 µg/ml in the control group were observed. Superoxide dismutase activity in children with severe malnutrition was 21.13±0.75 U/min per mg protein as compared to 26.02±0.66 U/min per mg protein in controls. Absence of breast-feeding, recurrent respiratory tract infection and diarrhoea correlated significantly with low serum Zn and Cu levels. Hypoproteinaemia and anaemia in malnourished children were also associated with a significant decline in both serum Zn and Cu levels. Conclusion:Serum trace element deficiency leading to depleted antioxidant protection may be a contributing factor to the pathophysiology of protein malnutrition and replacement of these elements in the management of this condition might be important.     

Effects of long-term exposure to Cu2+ and Cd2+ on the pentose phosphate pathway dehydrogenase activities in the ovary of adult Bufo arenarum: possible role as biomarker for Cu2+ toxicity

The effects of copper and cadmium on metabolism through the pentose phosphate pathway were evaluated in Bufo arenarum toad ovary. The effects of the two metals on dehydrogenases from this pathway were evaluated by three experiments: (1) in samples obtained from control females with addition of the metals to the reaction mixture (in vitro), (2) in samples obtained from control females and after long-term exposure of females to 4 and 100 microg/L of Cu or Cd in the incubation media (in vitro after exposure to the metals in vivo), and (3) 14CO2 production through the pentose phosphate pathway was evaluated after [U-14C]glucose microinjection on ovulated oocytes (in vivo after microinjection of the metals). Results from (1) evidenced inhibition of both enzyme activities but only above 1.5 mM Cu and Cd added to the reaction mixture. In (2) both glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities decreased in samples from the ovaries of females exposed in vivo to Cu, in a concentration-dependent manner (up to 90% in females exposed to 100 microg/L Cu: 2.12 +/- 1.57 NADPH micromol/min microg protein x 10(-5) vs 19.97 +/- 8.54 in control females). Cd treatment of the toads only rendered an inhibitory effect on 6-phosphogluconate dehydrogenase activity after exposure to 4 microg/L of the bivalent cation. (3) In vivo 14CO2 evolution significantly decreased in oocytes coinjected with 6.3 x 10(-3) mM Cu (calculated intracellular final concentration of the metal injected) and radioactive glucose. Cu and Cd concentration in samples from exposed females were always under detection limit by particle-induced X-ray emission. The results presented here are in agreement with a role for both glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities determination as biomarkers of effect and exposure for Cu but not for Cd toxicity.     

Oxidative DNA damage induced by a melatonin metabolite, 6-hydroxymelatonin, via a unique non-o-quinone type of redox cycle

Melatonin, an indolic pineal hormone, is produced primarily at night in mammals and is important in controlling biological rhythms. Although melatonin is known to be effective as a free radical scavenger and has an anti-cancer effect, carcinogenic properties have also been reported. In relation to its carcinogenic potential, we have examined whether 6-hydroxymelatonin, a major melatonin metabolite, can induce DNA damage in the presence of metal ion using [32P]-5'-end-labeled DNA fragments obtained from genes relevant to human cancer. 6-Hydroxymelatonin induced site-specific DNA damage in the presence of Cu(II). Formamidopyrimidine-DNA glycosylase treatment induced cleavage sites mainly at G residues of the 5'-TG-3' sequence, whereas piperidine treatment induced cleavage sites at T mainly of 5'-TG-3'. Interestingly, 6-hydroxymelatonin strongly damaged G and C of the 5'-ACG-3' sequence complementary to codon 273 of the p53 gene. These results suggest that 6-hydroxymelatonin can cause double-base lesions. DNA damage was inhibited by both catalase and bathocuproine, Cu(I)-specific stabilizer, suggesting that reactive species derived from the reaction of H2O2 with Cu(I) participate in DNA damage. Cytochrome P450 reductase efficiently enhanced 6-hydroxymelatonin-induced oxidative DNA damage and oxygen consumption, suggesting the formation of redox cycle. It is noteworthy that 6-hydroxymelatonin can efficiently induce DNA damage via non-o-quinone type of redox cycle. Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a characteristic oxidative DNA lesion, in calf thymus DNA was significantly increased by 6-hydroxymelatonin in the presence of Cu(II). Furthermore, 6-hydroxymelatonin significantly increased the formation of 8-oxodG in human leukemia cell line HL-60 but not in HP100, a hydrogen peroxide (H2O2)-resistant cell line derived from HL-60. The 6-hydroxymelatonin-induced 8-oxodG formation in HL-60 cells significantly decreased by the addition of bathocuproine or o-phenanthroline. Therefore, it is concluded that melatonin may exhibit carcinogenic potential through oxidative DNA damage by its metabolite.     

Interaction profile for lead, manganese, zinc, and copper

This interaction profile discusses and evaluates the evidence for joint toxic action among lead, manganese, zinc, and copper. The interaction profile recommends how to incorporate concerns about possible interactions or additivity into public health assessments of hazardous waste sites where people might be exposed to mixtures of these chemicals. The profile recommends using endpoint-specific hazard indexes and a hazard quotient to screen for potential health effects. The qualitative weight-of-evidence (WOE) approach is then used to predict the impact of interactions on the endpoint-specific hazard indexes and hazard quotient.     

Cross-resistance to cisplatin in cells with acquired resistance to copper

Purpose Cells selected for resistance to cisplatin (DDP) demonstrate cross-resistance to copper (Cu) suggesting one or more common mechanisms of cellular defense. We sought to determine whether cells selected for resistance to Cu are cross-resistant to DDP.Materials and methods Parental HuH7 human hepatoma cells and the CuR27 Cu-resistant subline were compared for sensitivity to Cu and DDP by clonogenic assay, and with respect to drug uptake and efflux by measuring cellular Cu and Pt content.Results CuR27 cells were found to be 1.8-fold resistant to Cu and 8.6-fold cross-resistant to DDP. Changes in the cellular pharmacokinetics of Cu in the CuR27 cells were paralleled by changes in the kinetics of DDP. The accumulations of Cu and DDP measured at 1 min were, respectively, 36% and 26% of those in the parental HuH7 cells. The initial rate of efflux from the CuR27 cells was 6.2-fold faster for Cu and 2.5-fold faster for DDP than from the HuH7 cells. Cu reduced the accumulation of DDP in the HuH7 cells in a concentration-dependent manner and vice versa. DDP also reduced the efflux of Cu. Western blot analysis demonstrated that expression of the Cu exporter ATP7B was increased 3.9-fold in the CuR27 cells.Conclusions In this model system, cross-resistance between Cu and DDP was bidirectional and accompanied by parallel changes in the cellular pharmacokinetics of both compounds. The results are consistent with the idea that transporters and chaperones that normally mediate Cu homeostasis also directly or indirectly modulate the accumulation of DDP.Abbreviations DDP Cisplatin - PBS Phosphate-buffered saline - TBS Tris-buffered saline     

Copper in drinking water: not a strong risk factor for diarrhoea among young children. A population-based study from Sweden

AIM: To assess whether mean daily intake of copper or maximal concentration of copper in drinking water is related to the incidence of diarrhoea and vomiting among young children. METHODS: Mean daily intake of copper from drinking water was estimated prior to episodes of diarrhoea among 430 children aged 9 to 21 mo. A total of 4703 samples of tap water were collected in the homes of the children. The mean daily intake of copper and the maximal concentration of copper in samples of consumed water were used as measures of exposure. The cumulative incidence of acute diarrhoea and vomiting was studied during 12 wk of follow-up. Cases of diarrhoea caused by viral and bacterial infections were identified. RESULTS: The median copper level of the mean value for each child was 0.61 mg/L with 10th and 90th percentiles of 0.04 and 1.57 mg/L. Among the 430 children, 43 had episodes of acute diarrhoea, of which 23 had no identified viral or bacterial origin, and vomiting was reported in 95 children. No significant associations were found between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting. CONCLUSION: There is unlikely to be a strong association between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting within the range of copper intakes/concentrations studied.     

Copper accumulation in actinomyces druses during endometritis after long-term use of an intrauterine contraceptive device

A 32-year-old woman carried a copper intrauterine contraceptive device (IUCD) or intrauterine pessar (IAP) for more than 5 years. She had acyclic menstrual bleedings and underwent a corpus abrasio after explantation of IUCD. The histological study of paraffin sections showed an actinomycotic endometritis with brown to black deposits in or around typical actinomyces druses, but there was no carcinoma. The electron microscopic study of these accumulations by electron energy loss spectroscopy (EELS) in TEM demonstrated copper deposits in the shell and matrix of these druses as well as inside the bacteria. With scanning electron microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDX), the electron-dense accumulations revealed high signals for copper and sulfur, but also of phosphorus and oxygen in a lower extent. This copper accumulation is discussed as an active uptake and concentration by these actinomyces bacteria.     

铜离子电化学疗法治疗痔出血及痔脱出的实验研究及临床观察

目的　观察利用铜离子电化学疗法治疗痔出血及痔脱出的疗效。方法　首先进行动物实验 :观察家兔止血时间及家兔肝、肾、肺间质组织血栓及血管壁水肿情况 ;观察铜质与钢质电极组织学变化并测定犬实验区与对照区铜离子浓度。再进行临床观察 :(1 )对 2 0 2例痔出血患者 (观察组 )用铜离子电化学疗法治疗 ,将铜针刺入痔区 1 0～ 1 5mm ,治疗 4min 40s,以同一方法逐一治疗各痔区。对 1 71例对照组使用痔疮宁栓及九华膏治疗。 (2 )痔脱出患者 1 2 8例为观察组 (混合痔 87例 ,内痔二期 2 9例 ,三期 1 2例 ) ,1 1 5例为对照组 (混合痔 75例 ,内痔二期 31例 ,三期 9例 )。均用铜离子电化学疗法治疗 ,观察组平均治疗脱出的痔区 9 8处 ,对照组平均治疗 3 4处。结果　 (1 )动物实验 :止血时间实验组为 (1 1 6± 0 1 8) ,对照组 (2 1 3± 0 46)min ,P <0 0 1。实验组可见大量血栓及血管壁水肿(但无上皮大量坏死 )。铜质电极作用好于钢质电极P <0 0 1。铜离子浓度 ,实验中心区 x50 7 33μg/ g ,较对照区 x1 1 63μg/ g明显增高 ,作用范围达 4cm。 (2 )临床观察 :痔出血观察组治愈率 98% ;显效率 1 5 % ;有效率 0 5 % ;无效率 0 %。对照组治愈率 1 1 1 % ;显效率 2 4 6 % ;有效率 2 8 1 % ;无效率 36 3 %