Stereo-ultrastructure of the surface of HeLa cells following exposure to the MPEL of a number of trace elements

Scanning electron microscopy was used to study the surface ultrastructure of HeLa cells after the incubation with maximum-permissible concentrations (MPC) of zinc, nickel, cobalt, cadmium and fluorine for 2, 4 and 24 hours. It was established that the action of zinc, nickel, fluorine was accompanied by the ultrastructural changes in plasmalemma up to the end of experiment. The effect of the cobalt and cadmium MPC was short-term, and cells restored their typical surface morphology within 24 hours.     

Dynamics of growth,proliferation and differentiation of wheat root cells exposed to a high nickel concentration

The dynamics of root growth, proliferation of initial cells of the root cap, rhizodermis, and central metaxylem, as well as structural changes in the cells induced by a 72-h exposure to a high (0.1 mM) concentration of NiSO₄ were studied in 3-day-old wheat (Triticum aestivum L.) seedlings. In the roots of control plants, we observed a 12-h rhythm of changes in the length of the cells that completed elongating. Upon the treatment with nickel, this effect was negated, and a considerable reduction in the root length increment was observed in 12 h. In 24 h, root growth essentially ceased. Cell elongation was suppressed acropetally, and the cells, whose elongation was over, became shorter. In the meristem and apical part of the elongation zone, slow cell growth continued during the second and even third days. Autoradiography showed that the earliest effect of nickel on the processes of root morphogenesis observed in 6 h was a suppression of cell transition to DNA synthesis. The cells, where DNA synthesis has already started or which were in other stages of the cycle, continued to pass slowly through the cycle and completed it. Sister cells formed as a result of division subsequently left the cycle in the phase G1 and transited to dormancy. It was found that the main mechanism of cell proliferation cessation was the suppression of cell transition to DNA synthesis. In the cells elongating when exposed to nickel, tissue-specific changes in the nucleus structure were observed (chromatolysis in the rhizodermis and cortex, pycnosis in the endodermis, a disturbance of the nucleus structure in the central metaxylem). These disorders were only observed after cessation of elongation. Root incubation in 0.1 mM nickel solution did not affect the onset of cell differentiation in the xylem and metaphloem and shifted its beginning to the root tip. However, in 24 h the initiation and growth of root hairs were suppressed. It was concluded that tissue-specific nickel-induced changes in the nucleus structure in the elongating cells do not cause the cessation of root growth, although point to nickel toxic effect on the cells in the course of elongation.     

Mitotic cycle of a HeLa cell culture exposed to the maximum permissible concentrations of trace elements

It is shown that administration of certain trace elements in maximum allowable concentrations induces changes in metabolism and functionation of cells in the culture. Zinc, nickel, cobalt, cadmium and fluorine are stated to inhibit mitotic activity of HeLa cells by the end of 24 hours of their action. Parallel with this they promote a decrease in H3-thymidine incorporation into DNA. Besides these substances delay various stages of the mitotic cycle for cells.     

Trace element uptake by L-cells as a function of trace elements in a synthetic growth medium

The concentration of trace elements in L-cells has been studied as a function of the trace metal content of the growth medium. Cells were cultured in synthetic media which contained varying trace amounts of the elements manganese, iron, cobalt, copper, zinc and molybdenum. The cellular concentration of the elements potassium, iron, copper and zinc were then determined. It was found that the cell accumulates trace metals at a different rate than they are made available. Deficiencies in zinc could be “induced” in the cell by increasing the concentration of iron, manganese and cobalt; cellular iron deficiencies were observed at larger medium concentrations of zinc, manganese, copper and cobalt. Trace metal uptake by the cell was seen to parallel the utilization by multicellular organisms.     

Levels of Heavy Metals and Trace Elements in Umbilical Cord Blood and the Risk of Adverse Pregnancy Outcomes: a Population-Based Study

To better understand the relationship between prenatal exposure to heavy metals and trace elements and the risk of adverse pregnancy outcomes, we investigated the status of heavy metals and trace elements level in a Chinese population by collecting umbilical cord blood. Umbilical cord blood heavy metals and trace elements concentrations were determined by inductively coupled plasma–mass spectrometry. No differences with statistical significance in the median arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), strontium (Sr), thallium (Tl), vanadium (V), and zinc (Zn) concentrations were observed between the adverse pregnancy outcome group and the reference group. Titanium (Ti) and antimony (Sb) were found at higher levels with statistical significance in the cord blood samples with adverse pregnancy group when compared to the ones in the reference group. The association between Ti levels and the risk of adverse pregnancy outcomes remained significant after adjusting for potential confounding factors, including newborn weight. These results indicated that environmental exposure to Ti may increase the risk of adverse pregnancy outcomes in Chinese women without occupational exposure.     

Factors that Affect the Content of Cadmium,Nickel, Copper and Zinc in Tissues of the Knee Joint

Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).     

Evaluation of homocysteine,vitamin, and trace element levels in women with gallstones

ObjectiveIt was aimed to examine the changes in homocysteine, folic acid, and vitamin B12, which metabolize homocysteine from the body, and trace elements (zinc, copper, selenium, nickel) that affect the structure of tissues and epithelium in female patients with gallstone disease. Moreover, it was aimed to investigate the contribution of these selected parameters to the etiology of the disease and their usability in treatment according to the findings obtained.Materials and MethodsEighty patients, including 40 female patients (Group I) and 40 completely healthy female individuals (Group II) were included in this study. Serum homocysteine, vitamin B12, folate, zinc, copper, selenium, and nickel levels were evaluated. Electrochemiluminescence immunoassay was used in the analysis of vitamin B12, folic acid, and homocysteine levels, and the ICP-MS method was used in the analysis of trace element levels.ResultsHomocysteine levels in Group I were statistically significantly higher than in Group II. In terms of vitamin B12, zinc, and selenium, Group I levels were found to be statistically significantly lower than group II. There was no statistically significant difference between Group I levels and Group II in terms of copper, nickel, and folate.ConclusionIt was suggested that homocysteine, vitamin B12, zinc, and selenium levels should be determined in patients with gallstone disease and that vitamin B12, which is especially important in the excretion of homocysteine from the body, and zinc and selenium, which prevent the free radical formation and protect from its effects, should be added to the diets of these patients.     

Comparative genomics of trace element dependence in biology

Biological trace elements are needed in small quantities but are used by all living organisms. A growing list of trace element-dependent proteins and trace element utilization pathways highlights the importance of these elements for life. In this minireview, we focus on recent advances in comparative genomics of trace elements and explore the evolutionary dynamics of the dependence of user proteins on these elements. Many zinc protein families evolved representatives that lack this metal, whereas selenocysteine in proteins is dynamically exchanged with cysteine. Several other elements, such as molybdenum and nickel, have a limited number of user protein families, but they are strictly dependent on these metals. Comparative genomics of trace elements provides a foundation for investigating the fundamental properties, functions, and evolutionary dynamics of trace element dependence in biology.     

Evaluation of Essential Trace and Toxic Elements in Scalp Hair Samples of Smokers and Alcohol User Hypertensive Patients

The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol. In the present study, trace and toxic elements were determined in scalp hair of patients diagnosed with hypertension who are smokers and habitual alcohol drinkers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmokers, nondrinking controls. The concentrations of trace and toxic elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference material (NCS ZC 81002b) and by the conventional wet acid digestion method on the same certified reference material and on real samples. The recovery of all the studied elements was found to be in the range of 97.5%–99.7% in certified reference material. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher in scalp hair samples of both smoker and nonsmoker hypertensive patients than referents (P < 0.001); whereas, the concentration of zinc was lower in the scalp hair samples of hypertensive patients of both genders. The deficiency of zinc and the high exposure of trace and toxic metals as a result of cigarette smoking and alcohol consumption may be synergistic with risk factors associated with hypertension.     

Comparative Metal Distribution in Scalp Hair of Pakistani and Irish Referents and Hypertensive Patients

The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the heavy metals (cadmium (Cd), nickel (Ni), lead (Pb), and zinc (Zn)) in scalp hair samples of 50 Irish and 78 Pakistani hypertensive patients of an urban population together with 50 Irish and 96 Pakistani non-hypertensive male subjects in the age group of 30–50 years. The concentrations of trace and toxic elements were measured by inductively coupled plasma–atomic emission spectrophotometer and atomic absorption spectrophotometer before microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials, and by the conventional wet acid digestion method on the same certified reference materials and on real samples. The recovery of all the studied elements was found to be in the range of 97.5–99.7% in certified reference material. The results of this study showed that the mean values of cadmium, nickel, and lead were significantly higher in scalp hair samples of both Pakistani and Irish hypertensive patients than in referents (p < 0.001); whereas, the concentration of zinc was lower in the scalp hair samples of hypertensive patients of both genders. The deficiency of zinc and the high exposure of trace and toxic metals may be the risk factors associated with hypertension.     

Plasma trace elements concentrations in trained subjects after exposure to hypokinesia and daily hyperhydration

The objective of this investigation was to evaluate the effect of a daily intake of fluid and salt supplementation (FSS) on blood plasma trace elements concentrations in physically healthy volunteers after exposure to 364 d of hypokinesia (decreased number of steps per day). The studies were performed after exposure to 364 d of Hypokinesia (HK) on 30 long-distance runners of volunteers who had a VO₂ max 67 mL/kg/min and were ranging in the age of 19–24 yrs. Prior to their exposure to HK all volunteers were on an average of 10,000 steps/d. For the simulation of the hypokinetic effect the volunteers were kept under an average of 3000 steps/d. All volunteers were divided into three equal groups. The first group of volunteers subjected to HK and received daily FSS (water 26 mL/kg body wt and sodium chloride 0.16 g/kg body wt.), the second groups of volunteers submitted only to HK, and the third group of volunteers underwent a normal ambulatory life and served as control. The content of manganese, calcium, magnesium, iron, lead, copper, tin, nickel, zinc and cobalamine were determined in blood plasma of volunteers. By the end of the hypokinetic period the blood plasma concentration of microelements increased significantly in the hypokinetic subjects (second group), whereas in the hyperhydrated subjects (first group) decreased. It was concluded that prolonged restriction of motor activity induced significant increases in blood trace elements concentrations whereas daily hyperhydration had a normalizing effect on their concentration in blood plasma. This indicates that daily hyperhydration may be used to normalize blood plasma concentrations of microelements in physically healthy volunteers subjected to prolonged restriction of motor activity.     

Serum changes in trace elements during thyroid cancers

The objective was to examine changes in trace elements due to thyroid cancer in humans. Serum levels and tissue contents of trace elements (Zn, Cu, Mn, Mg, Fe and Se) were measured in 43 patients with thyroid cancer before and 4 days after surgery were compared to normal values. The serum levels of zinc in cancer patients were lower than those of normal subjects. Surgical removal of the cancer resulted in the restoration of these levels. Although serum Cu levels in patients were not different from normal, but post-operatively these levels rose significantly (p < 0.001). Levels of Fe, Mg and Mn were significantly lower (p < 0.001) post-operatively. There was no significant change in Serum Se levels. The thyroid tissue contents of these trace elements did not show a difference between the normal (Juxta-tumor) thyroid tissue and the cancerous lesion. Out of the six trace elements examined, the decrease of serum levels of zinc in cancer patients may be linked to the disease condition. It is suggested that this change: (a) may be used to demonstrate successful cancer surgery and (b) may have implications for a long-term follow-up of thyroid cancer patients.     

Serum changes in trace elements during thyroid cancers

The objective was to examine changes in trace elements due to thyroid cancer in humans. Serum levels and tissue contents of trace elements (Zn, Cu, Mn, Mg, Fe and Se) were measured in 43 patients with thyroid cancer before and 4 days after surgery were compared to normal values. The serum levels of zinc in cancer patients were lower than those of normal subjects. Surgical removal of the cancer resulted in the restoration of these levels. Although serum Cu levels in patients were not different from normal, but post-operatively these levels rose significantly (p < 0.001). Levels of Fe, Mg and Mn were significantly lower (p < 0.001) post-operatively. There was no significant change in Serum Se levels. The thyroid tissue contents of these trace elements did not show a difference between the normal (Juxta-tumor) thyroid tissue and the cancerous lesion. Out of the six trace elements examined, the decrease of serum levels of zinc in cancer patients may be linked to the disease condition. It is suggested that this change: (a) may be used to demonstrate successful cancer surgery and (b) may have implications for a long-term follow-up of thyroid cancer patients.     

Entry of lethal doses of abrin, ricin and modeccin into the cytosol of HeLa cells

In attempts to assess how many molecules of the toxic lectins abrin, ricin and modeccin are needed in the cytosol to kill HeLa cells the effect of these toxins on protein synthesis and plating efficiency was studied. The incubation time of the cells after a 1 h exposure to the toxins influenced strongly the extent of inhibition of protein synthesis. The full toxic effect was expressed about 20 h of incubation after the exposure. On further incubation, protein synthesis again increased at a rate comparable to that in the control cells. After exposure to increasing concentrations of toxins the inhibition of cellular protein synthesis measured after 20 h showed excellent agreement with the inhibition of plating efficiency, indicating that the inhibition of protein synthesis can be used as a measure of cell killing. The inhibition of protein synthesis by toxins was found to follow first order kinetics, indicating that the cells are killed by an all- or none-effect. Autoradiographic studies indicated that after exposure to intermediate toxin concentrations protein synthesis was completely abolished in some cells, whereas it appeared to proceed at a normal rate in the remaining cells. The results provide evidence that penetration of one molecule of abrin, ricin or modeccin into cytosol is lethal to HeLa cells and that the efficiency of toxin entry into the cytoplasm is very low compared to the rate of bulk toxin uptake.     

Determination of Trace Elements in Jinqi,a Traditional Chinese Medicine

We have determined the trace element composition of Jingi, a common remedy used in traditional Chinese medicine, using atomic absorption spectrophotometer (AAS). The concentration of the trace elements analyzed in this medicine decreases in the order: zinc > manganese > chromium > magnesium > copper > iron > lead > nickel > vanadium. We suggest that these trace elements may play a direct or indirect role in the hypoglycemic properties of Jinqi. The three plants used as main ingredients in the preparation of this recipe should be planted in a lead-free soil rich in zinc, manganese, chromium, magnesium, and vanadium.     

Zinc-mediated inhibition of cyclic nucleotide phosphodiesterase activity and expression suppresses TNF-alpha and IL-1 beta production in monocytes by elevation of guanosine 3',5'-cyclic monophosphate

The trace element zinc affects several aspects of immune function, such as the release of proinflammatory cytokines from monocytes. We investigated the role of cyclic nucleotide signaling in zinc inhibition of LPS-induced TNF-alpha and IL-1beta release from primary human monocytes and the monocytic cell line Mono Mac1. Zinc reversibly inhibited enzyme activity of phosphodiesterase-1 (PDE-1), PDE-3, and PDE-4 in cellular lysate. It additionally reduced mRNA expression of PDE-1C, PDE-4A, and PDE-4B in intact cells. Although these PDE can also hydrolyze cAMP, only the cellular level of cGMP was increased after incubation with zinc, whereas cAMP was found to be even slightly reduced due to inhibition of its synthesis. To investigate whether an increase in cGMP alone is sufficient to inhibit cytokine release, the cGMP analogues 8-bromo-cGMP and dibutyryl cGMP as well as the NO donor S-nitrosocysteine were used. All three treatments inhibited TNF-alpha and IL-1beta release after stimulation with LPS. Inhibition of soluble guanylate cyclase-mediated cGMP synthesis with LY83583 reversed the inhibitory effect of zinc on LPS-induced cytokine release. In conclusion, inhibition of PDE by zinc abrogates the LPS-induced release of TNF-alpha and IL-1beta by increasing intracellular cGMP levels.     

Changes in Trace Elements During Early Stages of Chronic Kidney Disease in Type 2 Diabetic Patients

Trace elements can influence glucose metabolism and be related to oxidative stress in type 2 diabetes mellitus. Moreover, trace elements play important roles in the nephrotic complications of these patients. Nevertheless, few investigations have been made into the changes in the levels of trace elements in diabetic patients at various stages of chronic kidney disease (CKD). The aims of this present study were to determine the levels of some important trace elements in diabetic patients during the early stages of CKD and to identify the relationship between these elements and CKD progression in type 2 diabetic patients. One hundred and forty-eight type 2 diabetic patients with chronic kidney diseases were recruited into this study. The subjects were grouped into four stages (1, 2, 3a, 3b) of CKD, according to their urine protein levels and estimated glomerular filtration rates (eGFRs). The levels of serum zinc and iron exhibited a statistically significant decreasing trend (P trend?=?0.032 and 0.047, respectively) from stage 1 to stage 3b after adjustment for age, gender, smoking, alcohol consumption, education, hypertension, and body mass index. The other tested elements, including copper, magnesium, selenium, chromium, and manganese, did not display any significant trends upon proceeding from stage 1 to stage 3b. Thus, serum zinc and iron appear to be useful markers when evaluating the early progression of CKD in type 2 diabetic patients.     

The Distribution of Nickel, Copper, Zinc, and Iron in Tree Leaves

The distributions of nickel, copper, zinc, and iron in freshleaves from four tree species were studied using differentialoentrifugation of cell homogenates to fractionate the cell organellesand atomic absorption spectrophotometry to measure the concentrationsin the various fractions. Results from each species were closelysimilar. Approximately 90 per cent of the nickel was presentin the supernatant fraction while approximately 80 per centof the iron was present in the chloroplast fraction. Both copperand zinc had subcellular distributions similar to one anotherand contained appreciable amounts of the elements in both chloroplastand supernatant fractions. High-voltage paper electrophoretic separations of the solubleextracts of leaves showed that while copper, zinc, and ironexisted principally as anionic complexes, nickel existed asa cationio species. It was considered that this cationic formof nickel was unlikely to be an unchelated aquated cation.     

The roles of trace elements in foetal and neonatal development

Manganese, zinc and copper are essential for normal prenatal and neonatal development. Manganese deficiency causes skeletal abnormalities, congenital ataxia due to abnormal inner ear development, and abnormal brain function. Depression of mucopolysaccharide synthesis and manganese superoxide dismutase activity may be fundamental to ultrastructural and other defects. In copper deficiency, neurological and skeletal abnormalities are due to impairment of phospholipid synthesis and collagen crosslinking, and possibly to low activity of copper metalloenzymes. The fundamental defect leading to the extremely teratogenic effects of zinc deficiency is related to depressed synthesis of DNA. In the neonatal period, poor survival and growth and depressed function of the immune system are salient features. Developmental patterns of trace element concentrations in various tissues suggest that important changes in metabolic regulation of trace elements may occur during the neonatal period. This hypothesis is being investigated by studies of molecular localization of trace elements in certain neonatal tissues, in conjunction with similar observations in milk.