Trace element studies on four species of Fusarium.

Trace element studies were carried out on four species of Fusarium: F. moniliforme, F. solani, F. poae and F. bulbigenum. Out of fifteen trace elements tested, Fe, Zn, Mn, Cu, Mo and B were found to be essential for growth and sporulation of all these species of Fusarium. Optimum concentrations in ppm of essential trace elements of these fungi were as follows: F. moniliforme Fe 1.0, Zn 0.1, Mn 0.1, Cu 0.1, Mo 0.1, B 1.0-10.0; F. solani Fe 1.0, Zn 10.0, Mn 0.1, Cu 0.01, Mo 1.0, B 0.1; F. poae Fe 1.0, Zn 0.1, Mn 0.1, Cu 1.0, Mo 0.1, B0.1, F. bulbigneum Fe 10.0, Zn 1.0, Mn 1.0, Cu 1.0, Mo 0.01, B 1.0. Concentrations higher than the optimum were inhibitory to the respective fungi.     

Trace element determination in humans

With the present study, we intend to verify the utility of hair as diagnostic tool for trace element analysis, to substitute, perhaps, conventional materials, such as blood serum. Blood and hair were collected from male individuals (n=107) aged 20–59 y. Determinations of Cu and Zn concentrations were performed with atomic absorption spectrometry. An influence of age on Zn in hair has been found, with significantly different values before and after age 30 y. There is no correlation between Cu concentrations in hair and in serum, and a positive one (r=0.3554,p<0.05) between Zn levels in hair and in serum. No association between Zn and Cu levels in hair has been demonstrated; on the contrary, these elements have a moderate positive correlation in serum (r=0.3586,p<0.01). The data indicate that hair may represent an additional analytical material for Cu and Zn to complement blood serum.     

Trace element status of hemodialyzed patients

The trace elements Ba, Bi, Cd, Co, Cs, Cu, Hg, La, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn were determined by inductively coupled plasma mass spectrometry in plasma samples of 68 hemodialysis patients. The same elements (with exception of La and Mn) were also determined in whole blood after mineralization with high-purity nitric acid/hydrogen peroxide in a closed-pressurized microwave system. The accuracy and precision was checked by analyzing two Seronorm “whole blood” reference materials. All samples were contaminated with barium (heparinized tubes) and the plasma samples with tin (collection tubes). The concentrations for Bi, Hg, Pb, Rb, Sb, and Sr in whole blood were within the literature ranges for healthy adults. All of the concentrations for Co, and some of the concentrations for Cd, Cs, Tl, and Zn were higher than the high limits of the normal ranges. Approximately 14% of the Cu concentrations were lower than the low limit of the normal range. The Mo and Sn concentrations are difficult to evaluate, because the normal ranges appears to be unreliable. All concentrations for Cd, Co, Mo, Pb, Sn, and Sr and some of the concentrations for Cu (15%) and Mn (75%) in the plasma samples were higher than the high limits of the normal ranges. The concentrations for Rb tended to be lower than the normal range. To establish unequivocally the causes for elevated and reduced concentrations of trace elements in whole blood and plasma of dialysis patients, all fluids in the dialysis process must be investigated.     

Molecular biological approaches to plant nutrition

In the last decade, understanding of ion transport has grown sufficiently to pose sensible questions about the molecular nature of the processes and their regulation. Techniques for identifying and cloning genes and for genetic transformation provide the means for answering these questions.Transport of ions across membranes is obviously a major aspect of mineral nutrition since it occurs during initial absorption, compartmentation and mobilisation of nutrients. Here, we will briefly review the types of transport protein involved and show how molecular biology and recombinant DNA technology have revealed something of their structure. Strategies used to identify the genes for transporters are discussed and reference is made to areas in which the availability of cloned genes will facilitate future studies.Mineral nutrition involves, however, more than membrane transport. The absorption rates of major nutrients are quite strictly regulated by biochemical factors which vary with the rate at which nutrients are used in growth. Nitrogen, sulphur and phosphate nutrition in micro-organisms are regulated by the interaction of various DNA-binding proteins with the promoter regions of genes for key enzymes in the assimilatory pathways and the specific ion permeases. The expression of the regulatory protein or its activity can be modified by metabolites, such as glutamine. Some evidence supports the idea that higher plants also have groups of genes with a common regulation of expression.An attempt is made to identify some reasonable objectives, which should increase understanding of the regulation of nutrient transport.Abbreviations and conventions cDNA complementary strand of DNA prepared from a messenger RNA - NR nitrate reductase - NiR nitrite reductase - P_i inorganic phosphate - PPase pyrophosphate - RUBISCO rubulose bisphosphate carboxylase oxygenase. Genes are referred to as follows e.g. cys-3 and scon-1. The protein products of these genes, where they have no familiar name are referred to as CYS3 and SCON-1 respectively     

Trace element distribution in human eye

Biological Trace Element Research - A hundred samples of four types of eye tissues and hair from a set of 10 donors from the city of Prague were analyzed using INAA. The hair samples of the set of...     

Trace element profiles in cancer patients

It has become evident over the last two decades that there is an intimate relationship between the trace elements and cancer. Some trace elements have been shown to be carcinogens, others appear to provide protection against cancer. Profound changes in trace element concentrations and distribution occur in patients with cancer, but most changes remain undefined. A review of a number of studies of trace element changes in patients with cancer demonstrates that simple correlations of trace element levels in disease are of only limited use. Such reports underscore the need for large-scale studies that consider the many variables of malignancies and of trace element chemistry. The variables that must be considered for cancer include tissue of origin; histologic, pathologic and clinical staging; nutritional status as reflected by serum levels of calcium, iron, magnesium, phosphorus, the electrolytes, pH, albumen, and globulin; endocrine balance, effects of previous and concurrent therapies such as surgery, chemotherapy, hormonal manipulation, immunotherapy, and radiotherapy; history of exposure to toxic agents; and the presence of other disease. Similarly, trace element studies entail variables that must be considered and controlled prospectively, including timing and techniques of sampling, storage, and analysis, and simultaneous measurement of at least the majority of possibly interrelated elements rather than studying one element at a time. The various national cooperative oncology groups such as ECOG, SWOG, and SEOG now offer unusually well-studied groups of cancer patients who are managed according to carefully and prospectively defined protocols in participating institutions. With present knowledge, it is now time to approach these groups with a proposal to incorporate trace element studies in their protocols. A potential protocol will be discussed.     

Trace element inhibition of carcinogenesis and angiogenesis

In separate experimental models the effects of selenium, zinc, potassium, and copper on angiogenesis and carcinogenesis are compared. Inhibitory effects of Se as Na₂SeO₃ and of chloride salts of K and Zn, but not of Cu, on vascularization induced by amelanotic tumor implants (A Mel-4B32) in the Syrian hamster cheek pouch membrane are reported. In an earlier study the induction of new vasculature, angiogenesis, in control chambers implanted with A Mel-4B32 was initially observed on day 4 after implant. Addition of 5, 10, and 50 μg Se at the time of tumor implant delayed the initial capillary proliferation to days 7, 9, 10, respectively (Cancer Lett. 9, 353, 1980). Similarly, in this report addition of 50 μg Zn or 50 μg K delayed angiogenesis to days 7.and 6, respectively. By contrast, addition of 50 μg Cu caused severe inflammation and necrosis of the membrane before capillary proliferation could be observed and the animals had to be sacrificed. In an earlier study we reported the colon tumor incidence in 1,2-dimethylhydrazine (20 mg DMG/kg body weight for 20 weeks) -treated Sprague Dawley rats was reduced from 87 to 40% by a 4 ppm Se (as Na₂SeO₃) supplement in the drinking water (Cancer Lett. 2, 133, 1977). In this study rats were treated with the same dose of carcinogen, but were sacrificed 14 weeks following the last DMH injection. Drinking water supplements with 0.02% Zn (as ZnCl₂), 0.5% K (as KCl), or 0.01% Cu (as CuCl₂) were provided concurrently with the carcinogen and were continued until death or sacrifice. The colon tumor incidence was 18/20 in the DMH control and was reduced to 16/20 by supplemental Zn, reduced to 12/20 by supplemental K, and was unchanged (18/20) by Cu. The tumor incidences in the small intestine and Zymbal gland were all reduced by Zn, K, and Cu supplements compared with the DMH control. The hamster cheek pouch technique may provide a prescreen for potential inhibitors of chemical carcinogenesis in other experimental models.     

Nutrient element balance in citrus nutrition

Summary The inter-relationships between the leaf contents of 4 major nutrients, nitrogen, calcium, magnesium and potassium, are discussed within the context of a nutrient-element balance in citrus leaves. It was found that there was an unequal 3-way competition between the cations, potassium being perhaps the strongest antagonist of the three bases. There was also a reciprocative relationship between nitrogen and calcium, the data so far suggests a one-way phenomenon in favour of calcium. Furthermore the nitrogen/calcium ratio appears to have a significant effect on the leaf content of potassium, but not on the leaf content of magnesium.     

Trace element levels in the experimental peritonitis

Electron transfer from iron or copper ions to oxygen is an important example of cellular free radical initiation. Oxygen derived free radicals have been implicated as mediators of cellular injury in several model systems. To evaluate the importance of iron, copper and zinc levels on lipid peroxidation in peritonitis, we measured peritoneum malondialdehyde (MDA) as a marker of lipid peroxidation, zinc, copper, and iron levels during an animal model of intraperitoneal sepsis. Additionally the effects of the free radical scavenger alpha-tocopherol administration was studied. The peritoneum MDA, iron, copper and zinc levels were increased after induction of peritonitis with Escherichia Coli. The treatment with alpha-tocopherol was decreased the peritoneum MDA, iron and copper levels significantly, except the zinc level (p < 0.001, p < 0.001, p < 0.001, respectively). Additionally the alpha-tocopherol treatment for three days prior to injection of E.Coli more decreased MDA, copper and iron levels than that of the treatment with alpha-tocopherol at the time of injection of E. Coli (p < 0.001, p < 0.001, p<0.001, respectively). Our results indicated that copper, iron and zinc had important effects on peroxidation events in E. Coli induced peritonitis, and alpha-tocopherol treatment can improve the oxidant status.     

Nutrigenomics: integrating genomic approaches into nutrition research

It has been suggested that the supermarket of today will be the pharmacy of tomorrow. Such statements have been derived from recognition of our increasing ability to optimize nutrition, and maintain a state of good health through longer periods of life. The new field of nutrigenomics, which focuses on the interaction between bioactive dietary components and the genome, recognizes that current nutritional guidelines may be ideal for only a relatively small proportion of the population. There is good evidence that nutrition has significant influences on the expression of genes, and, likewise, genetic variation can have a significant effect on food intake, metabolic response to food, individual nutrient requirements, food safety, and the efficacy of disease-protective dietary factors. For example, a significant number of human studies in various areas are increasing the evidence for interactions between single nucleotide polymorphisms (SNPs) in various genes and the metabolic response to diet, including the risk of obesity. Many of the same genetic polymorphisms and dietary patterns that influence obesity or cardiovascular disease also affect cancer, since overweight individuals are at increased risk of cancer development. The control of food intake is profoundly affected by polymorphisms either in genes encoding taste receptors or in genes encoding a number of peripheral signaling peptides such as insulin, leptin, ghrelin, cholecystokinin, and corresponding receptors. Total dietary intake, and the satiety value of various foods, will profoundly influence the effects of these genes. Identifying key SNPs that are likely to influence the health of an individual provides an approach to understanding and, ultimately, to optimizing nutrition at the population or individual level. Traditional methods for identification of SNPs may involve consideration of individual variants, using methodologies such as restriction fragment length polymorphisms or quantitative real-time PCR assays. New developments allow identification of up to 500,000 SNPs in an individual, and with increasingly lowered pricings these developments may explode the population-level potential for dietary optimization based on nutrigenomic approaches.     

Trace element requirements in critically ill burned patients

Critically ill burned patients are characterized by a strong oxidative stress, an intense inflammatory response, and months-long hypermetabolism, all of which are proportional to the severity of injury. Trace element (TE) deficiencies have repeatedly been described. The clinical course is complicated by organ failures, infections, and delayed wound healing, which can be partly attributed to TE deficiencies.Among critically ill patients, TE deficiencies are the most severe in major burns, who suffer a specific copper deficiency. Plasma TE concentrations are low during any critical illness, as a result of TE losses in biological fluids, low intakes, dilution by fluid resuscitation, and redistribution from plasma to tissues mediated by the inflammatory response. The large exudative losses cause negative TE balances. Intravenous supplementation trials show that early substitution improves recovery, reduces infectious complications (particularly nosocomial pneumonia), normalize thyroid function, normalize skin tissue levels, improve wound healing and shorten hospital stay.Nevertheless, prolonged high dose delivery may be deleterious, as TE have potential for toxicity. In major burns, supplements up to 4 mg of Cu/day, 500 mg Se/day and 40 mg Zn/day for 3 weeks have been found to be safe and effective. The intravenous route appears the only way to deliver the doses required to achieve antioxidant and clinical effects. Further research is required to determine the optimal combination and doses for different severities of injury.     

Trace element budget in an African savannah ecosystem

The concentration of selected trace elements (Co, Cu, Fe, Mn, Mo, Se, and Zn) were analysed in soils, grass, bush, and tree samples from the Mole National Park, Ghana. The distribution of the essential nutrients: cobalt, copper, manganese, and selenium is controlled by bedrock geology, whereas iron, molybdenum, and zinc distribution is controlled by soil and hydrological processes. In the soils, iron, manganese, and cobalt are largely fixed in the mineral fraction while most of the copper, molybdenum, and selenium in the soils can be extracted by disodium ethylenediaminetetracetate. Copper, cobalt, and manganese appear to be preferentially concentrated in grass species while molybdenum and selenium are concentrated in browse plants. Variations in uptake exist between wet and dry seasons with all trace elements studied, except iron and manganese, showing a marked increased availability in the wet season and increased concentration in the residual fraction of the mineral and organic soils in the dry season. In the dry season the plant concentration of molybdenum and selenium decreased while copper and zine showed increased concentrations and this may be related to a lower pH of the groundwaters at this time. A budget of metal input and output in the ecosystem at Mole has been computed. From this potential dietary deficiencies in cobalt can be observed, however for other metals soil and plant concentrations are sufficient to prevent straightforward deficiencies while the concentrations of molybdenum and selenium are sufficiently low to be considered safe.     

Trace element content in breasts with fibrocystic disease

The trace elements antimony, bromine, cesium, cobalt, iron, rubidium, scandium, strontium and zinc were determined by instrumental neutron activation analysis in breast tissue samples with fibrocystic disease and in samples with fibroadenoma tumors. The histological lesions of each breast sample with fibrocystic disease were recorded, and a statistical analysis of the lesions in combination with the determined trace elements was carried out. The results showed that the element mean values in fibroadenoma tumors are higher than those of fibrocystic disease. Some other remarkable results of statistical examination are also presented.     

Trace element metabolism in the chemically diabetic rat

It is well-established that the metabolism of essential trace metals is homeostatically controlled. However, the factors responsible for coordinating processes of absorption, excretion, and flux among and within tissues remain unknown. Using the streptozotocin-diabetic rat as a model, we have obtained information in support of the hypothesis that the relative amounts of insulin and glucagon in plasma have a marked influence on the metabolism of the micronutrients Zn, Cu, Mn, and Fe. We have also found that alterations in trace metal metabolism during periods of acute stress (increased plasma glucagon to insulin ratio) are necessary for biochemical adaptation to the physiological state. Finally, we suggest that changes in the tissue distribution of these trace metals during periods of chronic endocrine imbalance may contribute to the onset of secondary complications.