Evaluation of Essential Trace and Toxic Elements in Biological Samples of Normal and Night Blindness Children of Age Groups 3–7 and 8–12 Years

The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb in scalp hair, blood, and urine of night blindness children age ranged 3–7 and 8–12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of As, Ca, Cd, K, Pb, Mg, Na, and Zn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p?<?0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.     

The predictive value of vitamin B12 concentrations and hyperhomocysteinaemia for cardiovascular disease

Background. Cardiovascular disease has been associated with both homocysteine and vitamin B12 levels. However, little information is available about the mutual relation in cardiovascular patients. The aim of this study was to assess the prevalence of vitamin B12 deficiency in patients with cardiovascular disease, and to study the correlation with homocysteine levels. Methods. Blood samples were taken from 229 patients who had been admitted to the Coronary Care Unit of the Heart-Lung Centre of the Radboud University Medical Centre in Nijmegen, the Netherlands. Patient demographics and clinical characteristics were assessed from medical files. Adjusted logistic regression was used to study the associations between vitamin B12, homocysteine and ischaemic heart disease. Results. In 70 patients (33%) serum vitamin B12 levels were below the lower limit of normal (<203 ng/l). Sixty-nine patients (33%) had vitamin B12 concentrations in the lower normal range (between 203 and 339 ng/l). Plasma homocysteine levels above the upper limit of normal were found in 83 out of the 229 patients (36%). Adjusted odds ratios for both vitamin B12 (0.76, 95% CI 0.44-1.30) and homocysteine (1.27, 95% CI 0.74-2.18) levels did not show a statistical association with ischaemic heart disease. No association was found between serum vitamin B12 levels and plasma homocysteine. Conclusion. Our data suggest that hyperhomocysteinaemia and low serum vitamin B12 concentrations are independent and cannot be used as a diagnostic tool for ischaemic heart disease. (Neth Heart J 2007;15:291-4.)     

Effects of inadequate vitamin E and/or selenium nutrition on the release of arachidonic acid metabolites in rat alveolar macrophages

Effects of vitamin E and/or selenium (Se) deficiency on the secretion of arachidonic acid metabolites by zymosan-stimulated pulmonary alveolar macrophages (AM) were examined using cells from male Long-Evans hooded rats fed torula-yeast based diets with or without the supplementation of vitamin E (150 IU/kg) or Se (0.5 mg/kg). Alveolar macrophages obtained by lavage were purified by adherence and cultured for 4 h in Hank's balanced salt solution containing bovine serum albumin (0.1%) and zymosan (300 micrograms/ml). The arachidonic acid metabolites present in the culture supernatant were measured by radioimmunoassay. Altered vitamin E and Se nutrition had no effect on the number of cells or cell types recovered from the pulmonary airways. Alveolar macrophages derived from animals fed on diets deficient in vitamin E or Se or both nutrients secreted higher levels of prostaglandin E2 and thromboxane B2. Levels of both 5-hydroxyeicosatetraenoic acid and leukotriene B4 were significantly increased only in the group fed the diet adequate in Se but deficient in vitamin E. Our data suggest that vitamin E and Se might play an important role to control the levels of several physiologically and pathologically important arachidonic acid metabolites.     

Arsenic and selenium measurements in nail and hair show important relationships to Alzheimer’s disease in the elderly

Background and research questionThe relationships of Arsenic (As) and selenium (Se) to Alzheimer’s Disease (AD) are not clearly known. This case-control observational study aims to investigate the possible relationship of these elements to the diagnosis and pathophysiology of the disease.MethodsThis case-control observational study was performed using 40 AD patients in different clinical stages and 40 healthy control subjects, living in a similar environment with low As exposure. The levels of As and Se in nail and hair were measured with Inductively Coupled Plasma Mass Spectrometry. The results were analysed with regards to clinical condition, age, disease duration, sex, education, living environment, and the relationship of the two elements using Mann Whitney U test and Spearman Rho or Pearson correlation tests as appropriate.ResultsThe levels of As and Se were not related to age, disease duration, sex, education, or living environment in the study groups (p > 0.05). The levels of As and Se in hair and nail samples of all patients and patient subgroups were higher than those in the healthy subjects (p < 0.001). A positive correlation was found between the levels of As and Se in both hair and nail samples only in the patient group (p < 0.01).ConclusionAccording to the results, As and Se levels probably increase due to some metabolic or genetic factors affecting both of them together. There may be an increase in the unregulated pool (selenomethionine) and a decrease in the regulated pool of Se (selenosycteine) in AD. Our findings need verification and the subject seems to deserve more elaborate evaluations including genetic analyses and analysis of different chemical forms of these elements.     

Arsenic and selenium in human hair

The selenium (Se) content of the diet and/or selenium supplements might have an ameliorating effect on arsenic (As) toxicity as recently shown by Wang et al. (1), Yang et al. (2), and as reviewed by Spallholz et al. (3). The underlying principles of the ameliorating effect is the complexation of Se with As forming the seleno-bis (S-glutathionyl) arsinium ion (4) excreted in bile and the complexation of Se with As in tissues forming nontoxic insoluble selenides (5,6). Addition protection afforded by Se supplementation from arsenicosis could be the elevation of glutathione peroxidase activity reducing the oxidative stress induced by As (7,8). The present study assessed the status of Se and As in hair by neutron activation analysis (NAA). Human hair samples were collected from the United States, Canada, The People's Republic of China (PRC), Bangladesh, and Nepal, the latter two countries now engaged in a struggle to find relief from human arsenicosis resulting from extensive domestic groundwater contamination by As. No statistically significant differences were observed in the samples between the Se and As content of hair from, Lubbock, Texas (USA) or Winnipeg, Canada. The concentration of As in all hair samples analyzed correlated (r=0.960, p<0.001) with the amount of As in the drinking water. Selenium levels in hair were highest from Nepal. The results demonstrate the viability of hair as a noninvasive biomonitor in assessing aspects of dietary Se and environmental As exposure. The hair data confirmed the known low intake of Se in the Keshan disease area of the PRC, the very high accumulation in hair of As from subjects consuming contaminated ground waters, and an adequate Se status in subjects from North America consuming municipal water of low As content. The high As content of hair from people in Bangladesh is the result of a high As consumption from contaminated water compounded by a less than desirable intake of Se (9). From Nepal, the As content of hair corresponded to the known low and high intake of As from contaminated groundwater. The very high Se content found in all hair samples from Nepal might be the result of the use of henna.     

Assessment of reference values for hair minerals of Korean preschool children

Hair samples of 655 children (3–6 yr of age) from metropolitan and small cities in Korea were analyzed to determine the content of 23 minor and trace elements with the aim of assessing reference values. Fifteen essential elements (Fe, Zn, Cu, Ca, Mg, Mn, P, Na, K, Cr, Se, Li, V, Co, Mo) and 8 harmful elements (Pb, Al, Hg, As, Cd, Ba, Bi, U) were taken into account. Measurements were performed by inductively coupled plasma-mass spectrometry. The overall mean values were as follows (μ/g): Al, 8.78; As, 0.11; Ba, 0.32; Bi, 0.04; Ca, 212.47; Cd, 0.08; Co, 0.01; Cr, 0.47; Cu, 15.51; Fe, 12.62; Hg, 0.49; K, 34.10; Li, 0.01; Mg, 12.29; Mn, 0.29; Mo, 0.07; Na; 27.14; P, 121.21; Pb, 1.68; Se, 0.75; U. 0.04; V. 0.08; Zn, 69.99. There was no significant difference in hair mineral content between children living in metropolitan and small cities. There were positive correlations between age and the level of Zn, Ca, Na, P, Mn, and Li, but negative correlations between age and the level of Cr, V, and U. The proposed reference values for hair Zn, Mg, Ca, As, and Cd of Korean children were lower than those of other countries, but the values for other elements of hair were not significantly different from those of other countries.     

Selenium, boron, and germanium deficiency in the etiology of Kashin-Beck disease

Concentrations of selenium (Se), boron (B), and germanium (Ge) were determined in scalp hair of children with Kashin-Beck disease (KBD), in healthy children in KBD-disease endemic areas, and in healthy children in non-KBD areas. Mean Se, B, and Ge concentrations were low in children with KBD; in hair of healthy children in KBD areas, Se levels were normal but B and Ge levels were lower than in KBD-free areas. The hair levels of B and Ge were unaffected by selenium supplementation. It is suggested that B and Ge deficiency may be contributing factors in the etiology of KBD.     

Erratum to: Lead Exposure: A Contributing Cause of the Current Breast Cancer Epidemic in Nigerian Women

Breast cancer incidence in Nigerian women has significantly increased during the past three decades in parallel with the rapid industrialization of that country. This suggested that the associated widespread contamination of the soil and of the water supplies by lead (Pb) and other industrial metals was a major contributing cause. Because of its many domestic, industrial, and automotive uses, Pb is of particular concern as it has been shown to promote the development of mammary tumors in murine mammary tumor virus-infected female C3H mice at levels as low of 0.5 ppm Pb in the drinking water. Lead belongs to the group of selenium-antagonistic elements that interact with selenium (Se), abolishing its anti-carcinogenic effect. Lead on chronic, low-level exposure in addition also accelerates tumor growth rates. Higher levels of Pb were found in blood and head hair samples of newly diagnosed patients with breast cancer, all with infiltrating ductal carcinoma, the most common form of breast cancer in Nigeria, seen at Obafemi Awolowo University, than in cancer-free controls from the same area. Evidence for interactions between Pb and Se was obtained from blood, hair, and tumor biopsy tissue analyses. Furthermore, the Pb levels in hair samples of the patients were directly correlated with the volumes of their tumors, in accord with the tumor growth-promoting effects of Pb. Conversely, Se levels in hair and blood were inversely correlated with the tumor volumes, consistent with the anti-proliferative effects of Se. Several other elements, e.g., Cd, Hg, Cr, Sn, and As, were detected in the scalp hair of the patients and the controls, although at significantly lower levels than those of Pb. However, correlation calculations revealed them also to interact with Se, suggesting that only a fraction of the Se in organs and tissues is actually present in bioactive forms. In metal-exposed subjects, a state of latent Se deficiency may exist, resulting in depressed immune functions and increased cancer susceptibility. Evidence is presented to show that Pb and other metals also interact with iodine, another vitally important essential trace element believed to protect against breast cancer development. Public health programs aiming at lowering the breast cancer risk of Nigerian women thus will have to include effective measures to protect the population from exposures to Pb and other industrial metals that are presently contaminating the environment and the water supplies.     

Effects of selenium deficiency on fatty acid metabolism in rats fed fish oil-enriched diets.

The hepatic fatty acid metabolism was investigated in rats stressed by selenium deficiency and enhanced fish oil intake. Changes in the composition of lipids, peroxides, and fatty acids were studied in the liver of rats fed either a Sedeficient (8 microg Se/kg) or a Se-adequate (300 microg Se/kg) diet, both rich in n-3 fatty acid-containing fish oil (100 g/kg diet) and vitamin E (146 mg alpha-tocopherol/kg diet). The two diets were identical except for their Se content. Se deficiency led to a decrease in hair coat density and quality as well as to changes in liver lipids, individual lipid fractions and phospholipid fatty acid composition of the liver. The low Se status did reduce total and reduced glutathione in the liver but did not affect the hepatic malondialdehyde level. In liver phospholipids (PL), Se deficiency significantly reduced levels of palmitic acid [16:0], fatty acids of the n-3 series such as DHA [22:6 n-3], and other long-chain polyunsaturates C-20-C-22, but increased n-6 fatty acids such as linoleic acid (LA) [18:2 n-6]. Thus, the conversion of LA to arachidonic acid was reduced and the ratio of n-6/n-3 fatty acids was increased. As in liver PL, an increase in the n-6/n-3 ratio was also observed in the mucosal total fatty acids of the small intestine. These results suggest that in rats with adequate vitamin E and enhanced fish oil intake, Se deficiency affects the lipid concentration and fatty acid composition in the liver. The changes may be related to the decreased levels of selenoenzymes with antioxidative functions. Possible effects of Se on absorption, storage and desaturation of fatty acids were also discussed.     

Effect of selenium and vitamin E dietary deficiencies on chick lymphoid organ development

Diets specifically deficient in selenium (Se) and/or vitamin E or adequate in both nutrients were fed to chicks from the time of hatching. Lymphoid organs (bursa, thymus, and in some instances, spleen) were collected from chicks 7-35 days of age. Growth of the chicks fed these diets was monitored over the experimental period as was lymphoid organ growth. The development of the primary lymphoid organs was further assessed by histological techniques and the organ contents of vitamin E (alpha-tocopherol) and Se were determined. Specific deficiencies of either Se or vitamin E were found to significantly impair bursal growth as did a combined deficiency. Thymic growth was impaired only by the combined deficiency diet. Severe histopathological changes in the bursa resulted from the combined deficiency and these were detectable by 10-14 days after hatching. These changes were characterized by a gradual degeneration of the epithelium and an accompanying depletion of lymphocytes. Similar changes, although slower to develop and less severe, were observed in the thymus as a result of the combined deficiency. When both serum and tissue levels of vitamin E and Se were monitored, it was observed that these were rapidly and independently depleted by the specific deficiency diets. These data suggest that the primary lymphoid organs are major targets of Se and vitamin E dietary deficiencies and provide a possible mechanism by which immune function may be impaired.     

Trace elements in children with autism spectrum disorder: A meta-analysis based on case-control studies

Autism spectrum disorder (ASD) is a common childhood neurodevelopmental disorder that may be related to trace elements. However, reports on the relationship between them are still inconsistent. In this article, we conducted a meta-analysis on this issue. We searched the PubMed, EMBASE, and Cochrane databases as of November 15, 2019. A random-effects model was used, and subgroups of studies were analyzed using samples of different measurements. Twenty-two original articles were identified (18 trace elements, including a total of 1014 children with ASD and 999 healthy controls). In autistic children, the overall levels of barium (Ba), mercury (Hg), lithium (Li), and lead (Pb) were higher. There were significant differences in the levels of copper (Cu) in the hair and serum between autistic children and the control group. The levels of Hg, Li, Pb and selenium (Se) in the hair of autistic children were higher than those of healthy children, while the levels of zinc (Zn) in the blood were lower. Excessive exposure to toxic heavy metals and inadequate intake of essential metal elements may be associated with ASD. Preventing excessive exposure to toxic metals and correcting poor dietary behaviors may be beneficial for the prevention and treatment of the disease.     

Trace element contents in hair of residents from Harbin (China), Medan (Indonesia), and Tokushima (Japan)

The concentrations of 19 trace element in hair samples from 1273 residents of Harbin (China), Medan (Indonesia), and Tokushima (Japan) were measured by inductively coupled plasma emission spectrometry. The mean concentrations of Ba, Ca, and Se were significantly higher in the Harbin hair samples when compared to those from Medan, but Al, B, Cu, Fe, Mn, Na, Pb, Ti, Zn, and K were significantly higher in Medan than in Harbin hair samples. The differences in the mean concentrations of As, Cr, Mg, P, Sn, and Sr between the Medan and Harbin lots were not significant. In the Tokushima hair samples, Na and K were significantly higher, but As, B, Ba, Ca, Cr, Mg, Mn, Pb, Sn, Sr, and Se were significantly lower than in the Harbin hair samples. The differences in the mean concentrations of Al, Cu, Fe, P, Ti, and Zn between Harbin and Tokushima were not significant. In the Medan hair samples, Al, As, B, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sn, Sr, Ti, and Zn were significantly higher, but P and Se were significantly lower than in Tokushima hair samples. Differences in mean concentrations of Na and K between Tokushima and Medan were not significant.     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

Dietary selenium- and vitamin E-induced alterations in some rabbit tissues

The present study was designed to investigate and compare the effects of dietary selenium (Se) and vitamin E on some physiological parameters and histological changes in liver, heart, and skin tissues, as well as the blood parameters and the related enzymes. Both sex young rabbits were fed with deficient (9.8 μg/kg diet), adequate (225 μg/kg diet), and rich (4.2 mg/kg diet) Se and vitamin E diets for 12–15 wk for this purpose. As the plasma Se levels and the erythrocyte glutathione (GSH) peroxidase activity decreased (79.8±9.4 ng/ml and 2.0±0.3 U/g Hb, respectively) in the deficient group, these values increased (100.4±2.7 ng/mL and 14.5±4.3 U/g Hb) in the rich group significantly with respect to the control group. The other antioxidant enzyme activities and the related element levels did not change significantly in either one of the experimental groups. Although the platelet counts of the two experimental groups were not different from the control values, the collagen and the adenosine diphosphate (ADP) stimulated platelet aggregation rate and intensity increased in the deficient group (p<0.05) and decreased very significantly (p<0.001) in the rich group. In both of the experimental groups, as the percentage values of the neutrophils decreased, the lymphocytes and the eosinophils increased significantly. According to the light microscopic investigations, the observed lesions of considerable intensity within the tissues that elicit cell degenerations were more pronounced in the animals fed with the rich diet than in those fed with the deficient diet. The deficiency as well as toxicity of Se and the deficiency of vitamin E caused several alterations in the physiological functions of the tissues, and these alterations were supported by the histological lesions within these tissues.     

Alterations in plasma total and high density lipoprotein cholesterol levels in hyperlipidemic rats fed diets with varied content of selenium and vitamin E

The effect of dietary selenium and vitamin E on plasma total (TC) and high density lipoprotein cholesterol (HDLC) was evaluated in 54 Sprague Dawley rats fed cholesterol/cholic acid enriched diets. Diets 1, 2, and 3 had no added selenium (low Se) and 0 (low), 60 (adequate), and 600 (high) mg/kg dL alpha tocopheryl acetate added respectively. Sodium selenite at 0.2 mg/kg (adequate Se) was added to diets 4, 5, and 6 and at 4.0 mg/kg (toxic Se) to diet 7, 8, and 9 with the same pattern of vitamin E added to the diet as described above. TC and HDLC were measured using the Kodak Ectachem system. Rats in the low and adequate Se groups fed high vitamin E had lower TC values than rats fed lower vitamin E levels but differences were not significant. In the toxic Se groups, rats fed high vitamin E had significantly (p<0.05) higher plasma TC values than did lower Vitamin E groups. Rats on the high vitamin E diets with low or adequate Se had significantly (p<0.05) higher mean plasma HDLC values when compared to rats fed low or adequate vitamin E diets. HDLC values for animals on Se toxic diets were significantly (p<0.05) lower in rats fed a low vitamin E diet. In rats fed Se deficient and adequate diets, a high vitamin E intake resulted in a decrease in TC and an increase in HDLC. In Se toxic rats, TC was elevated by a high dietary intake of vitamin E as was HDLC with both values being significantly higher than values found in the vitamin E deficient rats. Vitamin E deficiency resulted in a plasma lipid pattern that has been associated with greater cardiovascular disease risk.     

Effects of dietary selenite,copper, and zinc on tissue trace mineral levels in chicks

Studies were conducted to determine whether nutritional selenium (Se) status affects the nutritional status of the chick with respect to other trace elements, particularly copper (Cu) and Zinc (Zn). Severe Se deficiency was produced in chicks by the use of diets that contained exceedingly low contents (less than 0.010 ppm) of Se, but contained adequate amounts of all other known essential nutrients. This diet was based upon corn and soybean meal produced in areas of China with endemic Se deficiency of geobotanical origin. A level of at least 0.10 ppm Se was found to be required to maintain normal Se status of chicks fed this diet, and Se deficiency resulted in decreased levels of Cu, Zn, and molybdenum in the pancreas (liver and plasma levels were not affected). High dietary supplementation of Zn nor Cu did not affect the short-term utilization of Se, as indicated by the 18-h responses of Se-dependent glutathione peroxidase in plasma and liver.     

Trace Element Levels in Scalp Hair of School Children in Shigatse,Tibet, an Endemic Area for Kaschin-Beck Disease (KBD)

Kaschin-Beck disease (KBD) is an endemic osteoarthritis, and the etiology is closely related with levels of trace elements in the human body. Currently, it is clear that the selenium (Se) status of children in KBD areas is lower than that in non-KBD areas in the Tibetan Plateau, whereas role of other elements are yet unknown. This study aimed to assess some essential trace elements (Se, Mo, Mn, Zn, Fe, Cu, Co, and Sr) in children using scalp hair as a biomarker, and 157 samples from school children aged 8–14 years old were collected from both KBD and non-KBD areas in Shigatse, Tibet. Se and Mo were measured by inductive coupled plasma mass spectrometry, and the other elements were determined by inductive coupled plasma optical emission spectrometry. Compared with the non-KBD areas, Se, Mo, Mn, Fe, Zn, Co, and Sr levels of children in KBD areas were found to be significantly different (P < 0.05); while in linear discriminant analysis, only Se and Zn were found to contribute to the KBD prevalence in the study area. The hair Se level of children in KBD areas ranged from 0.115 to 0.299 mg/kg, while in non-KBD areas it ranged from 0.135 to 0.519 mg/kg. The Zn content of children’s hair was between 83 and 207 mg/kg in KBD areas, while it was 37 and 219 mg/kg in non-KBD areas. Lower Se and higher Zn levels in children in KBD areas was found when compared with non-KBD groups. In addition, Mo levels were found to be different between KBD areas and non-KBD areas on the opposite side of the Yarlung Zangbo River, but no close relationship was shown because there was no difference compared with the non-KBD area on the same side of the river. Our observations suggest that Se deficiency is still an important factor for the occurrence and prevalence of KBD, while the relationship between Zn and KBD needs to be further explored in the Tibetan Plateau.     

Effects of Different Selenium Application Methods on Wheat (<i>Triticum aestivum</i> L.) Biofortification and Nutritional Quality

Mineral nutrient malnutrition, especially deficiency in selenium (Se), affects the health of approximately 1 billion people worldwide. Wheat, a staple food crop, plays an important role in producing Se-enriched foodstuffs to increase the Se intake of humans. This study aimed to evaluate the effects of different Se application methods on grain yield and nutritional quality, grain Se absorption and accumulation, as well as 14 other trace elements concentrations in wheat grains. A sand culture experiment was conducted via a completely randomized 3 × 2 × 1 factorial scheme (three Se levels × two methods of Se application, foliar or soil × one Se sources, selenite), with two wheat cultivars (Guizi No.1, Chinese Spring). The results showed that both foliar Se and soil Se application methods had effects on wheat pollination. Foliar Se application resulted in early flowering of wheat, while soil Se application caused early flowering of wheat at low Se levels (5 mg kg⁻¹ ) and delayed wheat flowering at high selenium levels (10 mg kg⁻¹ ), respectively. For trace elements, human essential trace elements (Fe, Zn, Mn, Cu, Cr, Mo, Co and Ni) concentrations in wheat grains were dependent of Se application methods and wheat cultivars. However, toxic trace elements (Cd, Pb, Hg, As, Li and Al) concentrations can be decreased by both methods, indicating a possible antagonistic effect. Moreover, both methods increased Se concentrations, and improved grain yield and nutritional quality, while the foliar application was better than soil. Accordingly, this study provided useful information concerning nutritional biofortification of wheat, indicating that it is feasible to apply Se to conduct Se biofortification, inhibit the heavy metal elements concentrations and improve yield and quality in crops, which caused human health benefits.     

Physician's management of suspected vitamin B12 deficiency.

A retrospective study was undertaken to audit physician''s management of patients with a low serum level of vitamin B12 who were admitted to a university-affiliated teaching hospital during 1 year. Among the 34 patients 13 were proved to have pernicious anemia or vitamin B12 malabsorption, but for 12 of them there were unnecessary delays (several days or weeks) before initiation of investigation and therapy. An additional six patients, who had low serum levels of vitamin B12 and macrocytosis, most likely had true vitamin B12 deficiency, but proper investigation was not done and they did not receive any vitamin B12 or folic acid therapy. In another nine cases unexplained low serum levels of vitamin B12 were not properly investigated, and the patients either did not receive any vitamin B12 therapy or received it without proper documentation of a deficiency. Suggestions for facilitating early detection, investigation and treatment of megaloblastic anemia or vitamin B12 deficiency are given.     

The Correlation Between Smoking Status of Family Members and Concentrations of Toxic Trace Elements in the Hair of Children

Hair analysis is a promising tool for routine clinical screening and diagnosis of heavy metal exposure and essential trace element status in the human body. Systemic intoxications have been identified by anomalously high values of toxins in hair samples. The aim of the present study is to evaluate the relationship between smoking habit of the family members and the levels of toxic and nontoxic trace elements in hair samples of children. The randomized cross-sectional controlled study comprised of 95 children (41 girls and 54 boys) between the ages of 1 and 6 years. After written informed consent was obtained, a face-to-face interview was conducted with the families about educational background, total income of the family, and smoking habits of family members. The mineral elements considered in this study were Zn, Se, B, V, Co, Mo, Mn, iron (Fe), Be, aluminum (Al), As, cadmium (Cd), lead (Pb), Hg, chromium (Cr), Ag, Be, nickel (Ni), copper (Cu), Sn, and antimony (Sb). Hair mineral contents were measured by inductively coupled plasma-mass spectrometry. The results showed that the levels of Cd, Pb, Cr, Sb, Fe, and Al in hair samples of children whose parents smoked were significantly higher than those whose parents were nonsmokers. The number of smokers and the frequency of smoking at home were positively correlated with Pb, Cd, Cu, Ni, and Sb levels found. At the same time, it was found that there was no correlation between toxic element concentrations and family income or educational background excluding the levels of Cd. A correlation was observed between the smoking status of family members and levels of toxic trace elements in hair where this correlation was more significant with the levels of Pb and Cd. High socioeconomic status and the level of education of family members did not have any effect on toxic trace levels in hair samples of children.