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1.
Eighteen metals were estimated in the scalp hair samples from cancer patients (n = 111) and normal donors (n = 113). Nitric acid–perchloric acid wet digestion procedure was used for the quantification of the selected metals by flame
atomic absorption spectrophotometry. In the scalp hair of cancer patients, highest average levels were found for Ca (861 μg/g),
followed by Na (672 μg/g), Zn (411 μg/g), Mg (348 μg/g), Fe (154 μg/g), Sr (129 μg/g), and K (116 μg/g), whereas in comparison,
the dominant metals in the scalp hair of normal donors were Ca (568 μg/g), Zn (177 μg/g), Mg (154 μg/g), Fe (110 μg/g), and
Na (103 μg/g). The concentrations of Ca, Cd, Co, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr, and Zn were notably higher in the
hair of cancer patients as compared with normal donors, which may lead to a number of physiological disorders. Strong positive
correlations were found in Mn–Pb (0.83), Cd–Cr (0.82), Cd–Li (0.57), Fe–Pb (0.56), and Fe–Mn (0.55) in the hair of cancer
patients whereas Na–Cd, Li–Cr, Li–Co, Co–Cd, Li–Cd, Na–Co, Na–Li, Ca–Mg and Na–Cr exhibited strong relationships (r > 0.50) in the hair of normal donors. Principal Component Analysis (PCA) of the data revealed seven PCs, both for cancer
patients and normal donors, but with significantly different loadings. Cluster Analysis (CA) was also used to support the
PCA results. The study evidenced significantly different pattern of metal distribution in the hair of cancer patients in comparison
with normal donors. The role of trace metals in carcinogenesis was also discussed. 相似文献
2.
Hawkes WC Richter BD Alkan Z Souza EC Derricote M Mackey BE Bonnel EL 《Biological trace element research》2008,122(2):107-121
The essential nutrient selenium is required in microgram amounts [recommended dietary allowance (RDA) = 55 μg/day, 699 nmol/day]
and has a narrow margin of safety (upper tolerable intake limit = 400 μg/day, 5 μmol/day). We conducted a randomized placebo-controlled
study of high-selenium yeast, the form used in most supplements (300 μg/day, 3.8 μmol/day), administered to 42 free-living
healthy men for 48 weeks. Dietary intakes of selenium, macronutrients, and micronutrients were not different between groups
and did not change during the study. Supplementation more than doubled urinary selenium excretion from 69 to 160 μg/day (876
to 2,032 nmol/day). Urinary excretion was correlated with recent selenium intake estimated from 3-day diet records: urinary
selenium excretion = 42 μg/day (533 nmol/day) + 0.132 × dietary selenium intake, p < 0.001. Dietary selenium intake was not significantly correlated with the other indicators of selenium status, presumably
because urinary selenium excretion reflected recent intake, and tissue selenium was homeostatically controlled. After 48 weeks
of supplementation, plasma selenium was increased 60% from 142 to 228 μg/l (1.8 to 2.9 μmol/l), and erythrocyte selenium was
approximately doubled from 261 to 524 μg/l (3.3 to 6.6 μmol/l). Selenium concentrations increased more modestly in hair (56%)
and platelets (42%). Platelets were the only blood component in which glutathione peroxidase activity was significantly related
to selenium content. Selenium levels decreased rapidly after the end of supplementation, and there were no significant differences
in selenium status indicators between groups by week 96. The absorption, distribution, and excretion of selenium from high-Se
yeast were similar to selenium in foods. 相似文献
3.
Five brands of antidiabetic herbal formulations as tablets, Diabetex, Divya Madhu Nashini, Jambrushila, Diabeticin, and Madhumeh Nashini, from different pharmacies were analyzed for six minor (Na, K, Ca, Cl, Mg, and P) and 20 trace (As, Ba, Br, Ce, Co, Cr, Cs,
Cu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V, and Zn) elements by thermal neutron irradiation followed by high-resolution
gamma ray spectrometry. Further Ni, Cd, and Pb were determined by atomic absorption spectrophotometry. Most elements vary
in a narrow range by a factor of 2–4 while a few others vary in a wide range, e.g., Na (0.05–0.67 mg/g), Mn (26.7–250 μg/g),
and V (0.26–2.50 μg/g). All the five brands contain K, Cl, Mg, P, and Ca as minor constituents along with mean trace amounts
of Cr (2.11 ± 0.67 μg/g), Cu (15.7 ± 7.11 μg/g), Fe (459 ± 171 μg/g), Mn (143 ± 23 μg/g), Se (238 ± 112 ng/g), and V (0.99 ± 0.93 μg/g).
Jambrushila is enriched in Na, Ca, Mg, Cl, Fe, Cu, Se, and Zn, essential nutrients responsible for curing diabetes. Dietary intake of
Mn, Fe, and Cu are greater than 10% of the recommended dietary allowance, whereas that for Zn and Se is less than 2%. Mean
contents of toxic elements (As, Cd, Hg, and Pb) were found below permissible limits except in Jambrushila. Cr and Zn were inversely correlated with r = −0.81, whereas Rb and Cs exhibit linear correlation (r = 0.93) in five brands. C, H, N analysis showed C ∼ 55%, H ∼ 12%, and N ∼ 2% with a total of ∼70% organic matter. However,
thermal decomposition studies at 700°C suggest less than 5% nonvolatile metal oxides. Herbal formulations contain minor and
trace elements in bioavailable forms that favorably influence glucose tolerance and possibly increase the body’s ability to
ameliorate development of diabetes. 相似文献
4.
Objective Study the effects of acute and chronic restraint stress on the whole blood concentrations of iron (Fe), zinc (Zn), calcium
(Ca), and magnesium (Mg) in mice.
Materials and methods Single or repeat restraints were applied to mice to induce acute or chronic stress. The levels of elements in whole blood
were determined by flame atomic absorption spectrometry.
Results The levels of Fe, Zn, Ca, and Mg in blood in the acute-stress group were 351, 5.05, 60, and 44 μg/ml, respectively, and those
in the corresponding control group were 391, 5.90, 59, and 45 μg/ml, respectively. The levels of blood Fe, Zn, Ca, and Mg
in the chronic-tress group were 291, 3.62, 59, and 40 μg/ml, respectively, and those in the corresponding control group were
393, 4.82, 48, and 43 μg/ml, respectively. The levels of Fe and Zn in the blood of both the acute-stress and the chronic-stress
groups were significantly lower (P < 0.05) than that in the control groups. The Ca level in whole blood was significantly (P < 0.05) higher in the chronic-stress group than that in the control group.
Conclusion Acute and chronic restraint stress can cause changes in blood levels of Fe and Zn in mice. 相似文献
5.
Ersoy IH Koroglu BK Varol S Ersoy S Varol E Aylak F Tamer MN 《Biological trace element research》2011,143(2):619-624
Although there are many studies on effect of fluoride on trace elements in experimental animals, few studies exist on serum
trace elements levels in patients with endemic fluorosis. We aimed to determine the serum levels of trace elements including
serum copper (Cu), zinc (Zn), and serum levels of minerals including calcium (Ca), phosphorus (P), magnesium (Mg), sodium
(Na), potassium (K) in patients with endemic fluorosis. The study group consisted of 30 patients with endemic fluorosis (17
females, 13 males, mean age 33.53 ± 9.85 years). An age, gender, and body mass index matched 30 healthy volunteers comprised
control group (21 females, ten males with a mean age 33.93 ± 7.39 years). Urine fluoride levels of chronic fluorosis patients
were significantly higher than that of control subjects as expected (1.92 ± 0.10 mg/l vs. 0.41 ± 0.09 mg/l, respectively;
P < 0.001). Serum Cu levels (89.14 ± 16.77 μg/dL vs. 102.69 ± 25.04 μg/dL, respectively, P = 0.017), serum Zn levels (77.98 ± 20.58 μg/dL vs. 94.57 ± 35.87μg/dL, respectively, P = 0.032), and serum Mg levels (1.92 ± 0.18 mg/dL vs. 2.07 ± 0.31 mg/dL, respectively, p = 0.022) was significantly lower in chronic fluorosis patients than in controls. There were no statistically significant
differences between the fluorosis group and control group with respect to serum levels of Na, K, Ca, and P. We concluded that
chronic fluorosis is associated with reduced serum levels of Cu, Zn, and Mg. 相似文献
6.
Qaisara Pasha Salman A. Malik Nazia Shaheen Munir H. Shah 《Biological trace element research》2010,134(2):160-173
Trace elements including Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr, and Zn were analyzed in the scalp hair
samples of women with malignant breast lesions, women with benign breast lesions, and healthy donors using atomic absorption
spectrophotometric method. In the scalp hair of malignant-tumor patients, the highest average concentration was shown by Ca
(1,187 μg/g), followed by Na (655 μg/g), Mg (478 μg/g), Zn (391 μg/g), Sr (152 μg/g), Fe (114 μg/g), and K (89.8), while in
the case of benign-tumor patients, the average estimated element levels were 1,522, 1,093, 572, 457, 217, 80.4, and 74.7 μg/g,
respectively. Most of the elements exhibited non-normal distribution evidenced by large spread, standard error, and skewness
values. Mean concentrations of Ca (634 μg/g), Zn (206 μg/g), Mg (162 μg/g), Fe (129 μg/g), and Na (82.1 μg/g) were noteworthy
in the scalp hair of healthy women. Average levels of Na, Sr, K, Cd, Co, Pb, Mg, Ca, Zn, Ni, Sb, and Mn were revealed to be
significantly higher in the hair of malignant and benign patients compared to the healthy women; however, Fe, Cu, Al, and
Cr were not significantly different in the scalp hair of the three groups. The quartile distributions of Ca, Cd, Co, Cr, K,
Mg, Mn, Na, Ni, Pb, Sb, and Sr revealed maximum spread in the scalp hair of malignant and benign groups; nevertheless, Al,
Cu, Fe, and Zn exhibited almost comparable quartile levels in the three groups. Strong correlation coefficients were found
between Fe and Cd, Al and Na, Mn and Sr, Co and Cr, Cd and Cr, Pb and K, Pb and Mn, Cu and Na, and Al and Fe in the scalp
hair of malignant-tumor patients, while Fe and K, Cd and Co, Na and Co, and Cr and Pb showed strong correlations in the scalp
hair of benign-tumor patients, both of which were significantly different compared with the healthy subjects. Multivariate
cluster analysis also revealed divergent clustering of the elements in the scalp hair of malignant and benign patients in
comparison with the healthy women. 相似文献
7.
Teng X Shi X Shan Z Jin Y Guan H Li Y Yang F Wang W Tong Y Teng W 《Biological trace element research》2008,121(1):23-30
Iodine excess may lead to thyroid diseases. Our previous 5-year prospective survey showed that the prevalence and incidence
of hypothyroidism or autoimmune thyroiditis increased with iodine intake. The aim of the present study was to investigate
the optimal range of iodine intake by comparing the prevalence of thyroid diseases in three areas with slightly different
levels of iodine intake. In 2005, 778 unselected women subjects from three areas with different iodine intake levels were
enrolled. Levels of serum thyroid hormones, thyroid autoantibodies, and urinary iodine were measured, and thyroid B ultrasounds
were performed. Among the subjects with mildly deficient iodine intake, those with adequate intake, and those with more than
adequate intake, the prevalence of clinical and subclinical hypothyroidism was 0, 1.13, and 2.84%, respectively (P = 0.014); that of thyroid goiter was 24.88, 5.65, and 11.37%, respectively (P < 0.001); that of serum thyrotropin values was1.01, 1.25, and 1.39 mIU/l, respectively; and that of serum thyrotropin/thyroglobulin
ratio was 7.98, 6.84, and 5.11, respectively (P < 0.001). In conclusion, median urinary iodine 100~200 μg/l may reflect the safe range of iodine intake levels. Serum thyrotropin/thyroglobulin
ratio might be a better index of evaluating iodine status. 相似文献
8.
The use of hair and bone as media in evaluation of lead exposure was investigated in this study. For 12–16 wk rats were given
tap water containing lead acetate in the following concentrations: 41.7 mg Pb/L, 83.3 mg Pb/L, and 166.6 mg Pb/L. The animals
were sacrificed every 4 wk and their tibia bones and hair were collected for determination of lead content. In control animals,
the lead level amounted to 1.2 μg/g (range 0.8–1.3 μg/g) and 0.7 μg/g (range 0.4–2.0 μg/g) in bone and hair, respectively.
In the treated rats the accumulation of lead in bone and hair occurred in a dose-dependent manner. A positive corelation (r=0.876) was established between the lead levels in bone and hair of the rats. The regression equation was as follows: μg Pb/g
bone=0.842×μg Pb/g hair+1.868. After discontinuation of exposure, a significant decrease in the lead content in bone and hair
was noticed. About 9 wk after cessation of treatment, the lead content in hair declined to the pre-exposure level, but 64%
of the maximal lead concentration did remain in bone. The results of this study indicate that during a continuous exposure
the lead level in hair reflects its content in bone. Such phenomena did not occur during the postexposure period. 相似文献
9.
The concentrations of arsenic (As), beryllium (Be), cadmium (cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni),
lead (Pb), tin (Sn), thallium (Tl), and vanadium (V) were determined in a number of food items purchased in zones of Tarragona,
County (Catalonia, Spain) near a hazardous waste incinerator (HWI), which has been operating since 1999. Food samples corresponded
to the following groups: meat, fish and seafood, pulses, cereals, vegetables, fruits, tubers, whole milk, yogurt, eggs, and
sugar. Be and Tl were under their respective limits of detection in all samples. For the analyzed trace elements, the dietary
intake by the general population of Tarragona was 458.5 μg/d for As, 14.3 μg/d for Cd, 88.3 μg/d for Cr, 5.3 μg/d for Hg,
2421.4 μg/d for Mn, 138.3 μg/d for Ni, 44.8 μg/d for Pb, 34.6 μg/d for Sn, and 28.9 μg/d for V. Results were compared with
those found in a baseline survey carried out in the same area during the construction of the HWI (1996–1998). In general terms,
the dietary intake of metals in 2003 was comparatively similar to those found in the baseline survey. For the most toxic elements
(As, Cd, Hg, and Pb), it was under their respective Provisional Tolerable Weekly Intake (PTWI) estabished by the FAO/WHO. 相似文献
10.
Ono EY Fungaro MH Sofia SH Figueira EL Gerage AC Ichinoe M Sugiura Y Ueno Y Hirooka EY 《Mycopathologia》2004,158(4):451-455
Eleven feed samples associated with six animal (horse and poultry) intoxication outbreaks (1991) in the state of Paraná, Brazil,
were evaluated for fungal and fumonisin contamination. In order to estimate the␣trend of livestock intoxication, fumonisin
contamination was monitored in corn produced both at the commercial level (1991, 1995 crop), and in an experimental field
at a local Agronomy Institute (1997 crop). The total mould count in the feed samples ranged from 2.9 × 103 to 1.9 × 107 CFU/g, with Fusarium verticillioides as the predominant species, at a high count of 2.4 × 104–6.5 × 105 CFU/g. Fumonisins (FB1 + FB2) were detected in all corn-based feed samples at levels ranging from 2.89 to 14.54 μg/g. All 27 Northern corn samples (1991 crop) were contaminated with fumonisins at levels ranging from 2.32 to 16.64 μg/g. Twenty-six (96.3%) out of 27 corn samples from the Central-Southern region (1995 crop) were positive for fumonisins (FB1+FB2), with the range of 0.07–3.66 μg/g, while all 37 Northern samples (1995 crop) were contaminated with fumonisins ranging from 0.57 to 9.97 μg/g. Twenty-one out of 37 corn samples from the Northern region (1997 crop) were positive for fumonisins, but at low level
(range of 0.05–2.67 μg/g). The results showed a decreasing trend in fumonisin contamination over the years. Nowadays animal intoxication outbreaks
rarely occur in this State, as both animal producers and feed industries have become conscious about monitoring of corn and
other raw materials at the quality control level. 相似文献
11.
Sieved agricultural soil samples were treated with the anti-knock agent tetraethyl lead (Et4Pb), and the resulting effects were analyzed by microcalorimetry. Et4Pb additions resulted in an increase of the heat production rate, provided that oxygen was present and that the soil was not
autoclaved. The increased heat production rate was accompanied by degradation of Et4Pb, as verified by speciation analysis (GC-MS) of the remaining Et4Pb and its ionic degradation products (triethyl lead and diethyl lead cations). Conclusive evidence was obtained that these
transformations were mediated mainly by microbes. At an initial Et4Pb concentration of 2 g Pb/kg dry weight the biodegradation rate was about 780 μmol day−1 kg dry weight−1, whilst the chemical decomposition was only 50 μmol day−1 kg dry weight−1. A fivefold rise of the initial Et4Pb concentration resulted in a decrease of the biodegradation rate to 600 μmol day−1 kg dry weight−1 and an increase of the chemical decomposition to 200 μmol day−1 kg dry weight−1. The biodegradation rate was not influenced by the addition of glucose, which means that no indication for a cometabolic
attack of Et4Pb was found.
Received: 25 February 1997 / Received revision: 22 April 1997 / Accepted: 27 April 1997 相似文献
12.
Masayuki Ikeda Shinichiro Shimbo Takao Watanabe Fumiko Ohashi Yoshinari Fukui Sonoko Sakuragi Jiro Moriguchi 《Biological trace element research》2011,139(3):269-286
Successful trials were made to estimate the dietary daily intake of lead (Pb) and cadmium (Cd) via foods from the levels of
the metals in blood or urine. In practice, 14 and 15 reports were available for Pb and Cd in blood (Pb-B and Cd-B), urine
(Pb-U and Cd-U) and 24-h diet duplicates (Pb-D and Cd-D), respectively, from which 68 pairs each of Pb or Cd in blood and
food duplicates [each being geometric mean (GM) values for the survey sites] were obtained. Regression analysis revealed that
there was a significant correlation between Pb-B and Pb-D, and also between Cd-B and Cd-D, suggesting that it should be possible
to estimate both Pb-D and Cd-D from Pb-B and Cd-B, respectively. For Cd-U, the number of available cases was limited (20 pairs),
but a significant correlation was detected between Cd-U (as Cd-Ucr, or Cd levels in urine as corrected for creatinine concentration) and Cd-D. Care should be taken in estimating Pb-D from
Pb-B, as the ratio of Pb-D over Pb-B may decrease as a function of increasing Pb-B levels. The Pb-D (μg/day) for typical Japanese
women with Pb-B of 15 μg/l was best estimated to be 13.5 μg/day. No Cd-B- or Cd-Ucr-dependent change was detected in case of Cd. The best estimate of Cd-D for Cd-B at 1.5 μg/l should be about 19.4 μg/day. 相似文献
13.
Barton HJ 《Biological trace element research》2011,143(2):637-658
The population of about 300 6-year-old preschool children was studied for lead (Pb) and cadmium (Cd) in deciduous teeth, scalp
hair, and capillary blood. Zinc (Zn) content in hair was also measured due to its possible interferences with the elements
studied. The Pb and Cd contents were measured by graphite furnace atomic absorption spectrometry with Zeeman background correction,
and Zn, by flame method. Metal levels found were comparable to those in European countries. Positive correlations between
Pb and Cd in the same and different tissues were widespread (r = 0.23–0.68). A positive correlation was found between Pb in teeth and blood (r = 0.65, p < 0.001). Pb blood threshold 100 μg L−1 referred to 2.6 μg g−1 Pb in teeth. Predictability of this Pb teeth limit was 14% vs. 5% for Pb blood. Strong negative correlation was found between
hair Pb and Zn (r = −0.68, p < 0.001). Enhanced Cd and Zn levels in hair were associated with the household drinking water hardness. The associations
with some other environmental and behavioral factors were also presented and discussed. The results proved the advantage of
analysis of primary teeth for Pb exposure screening of preschool children. 相似文献
14.
One hundred sixty-four adult male volunteers (29 controls [Group 1] and 135 combi drivers) enrolled in the study. The combi
drivers were divided into three groups as nonusers of either Maras powder or cigarette (Group 2), smokers (Group 3), and users of Maras powder (Group 4). Blood lead levels (BLLs) were analyzed by
atomic absorption spectrophotometer. BLL was detected as 2.8 ± 2.3 μg/dL in Group 1 (n = 29); however, it was 3.5 ± 1.6 μg/dL in Group 2 (n = 33), 3.8 ± 2.4 μg/dL in Group 3 (n = 62), and 3.9 ± 2.4 μg/dL in Group 4 (n = 40). BLL in Group 1 was found significantly lower than other groups (p < 0.05). The use of cigarette or Maras powder by the drivers did not give rise to a marked difference on the BLLs (p > 0.05). BLL of (combi) drivers was detected to be significantly higher than nondrivers; however, it was still under the
hazardous level of 10 μg/dL announced by WHO. Although there are publications reporting that usage of tobacco increases the
level of lead in blood, both smoking and use of Maras powder did not affect BLL markedly in our study.
Poster presented (the abstract section published in Congress Book) at the 7th Congress of Turkish Family Physicians, 23–26
May 2006, Cesme-IZMIR, Turkey. 相似文献
15.
Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline
studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences
in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian
communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural
and urban subjects was 997 ± 333 and 979 ± 290 μg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 ± 367 μg/L) than the rural males (898 ± 249 μg/L;
p = 0.0085). Se levels for rural/urban subjects were 97 ± 36 and 87 ± 31 μg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 ± 218 and 150 ± 102 μg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 ± 204 μg/L) than the urban females (166 ± 103 μg/L;
p = 0.0002). Finally, Zn was significantly higher in rural females (428 ± 204 μg/L) than males (172 ± 116 μg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low
Zn levels were confirmed in another cohort follow-up study. 相似文献
16.
Rahman A Azad MA Hossain I Qusar MM Bari W Begum F Huq SM Hasnat A 《Biological trace element research》2009,127(2):102-108
The purpose of the study was to determine the concentration of trace elements present in scalp hair sample of schizophrenic
patients and to find out the relationship between trace elements level and nutritional status or socioeconomic factors. The
study was conducted among 30 schizophrenic male patients and 30 healthy male volunteers. Patients were recruited from Bangabandhu
Sheikh Mujib Medical University by random sampling. Hair trace element concentrations were determined by flame atomic absorption
spectroscopy and analyzed by independent t test, Pearson’s correlation analysis, regression analysis, and analysis of variance (ANOVA). Mn, Zn, Ca, Cu, and Cd concentrations
of schizophrenic patients were 3.8 ± 2.31 μg/gm, 171.6 ± 59.04 μg/gm, 396.23 ± 157.83 μg/gm, 15.40 ± 5.68 μg/gm, and 1.14 ± 0.89 μg/gm
of hair sample, while those of control subjects were 4.4 ± 2.32 μg/gm, 199.16 ± 27.85 μg/gm, 620.9 ± 181.55 μg/gm, 12.23 ± 4.56 μg/gm,
and 0.47 ± 0.32 μg/gm of hair sample, respectively. The hair concentration of Zn and Ca decreased significantly (p = 0.024; p = 0.000, respectively) and the concentration of Cu and Cd increased significantly (p = 0.021; p = 0.000, respectively) in schizophrenic patients while the concentration of Mn (p = 0.321) remain unchanged. Socioeconomic data reveals that most of the patients were poor, middle-aged and divorced. Mean
body mass indices (BMIs) of the control group (22.26 ± 1.91 kg/m2) and the patient group (20.42 ± 3.16 kg/m2) were within the normal range (18.5−25.0 kg/m2). Pearson’s correlation analysis suggested that only Ca concentration of patients had a significant positive correlation
with the BMI (r = 0.597; p = 0.000) which was further justified from the regression analysis (R
2 = 44%; t = 3.59; p = 0.002) and one-way ANOVA test (F = 3.62; p = 0.015). A significant decrease in the hair concentration of Zn and Ca as well as a significant increase in the hair concentration
of Cu and Cd in schizophrenic patients than that of its control group was observed which may provide prognostic tool for the
diagnosis and treatment of this disease. However, further work with larger population is suggested to examine the exact correlation
between trace element level and the degree of disorder. 相似文献
17.
Molybdenum Content of Canadian and US Infant Formulas 总被引:1,自引:0,他引:1
Molybdenum is an essential trace nutrient in the human diet. Our purpose was to provide a comprehensive analysis of Mo content
of various types of powdered infant formulas across Canada and the USA. All infant formulas, available on the day of sampling,
were purchased from random supermarkets in Grand Forks, ND, USA; San Diego, CA, USA; Washington, DC, USA; and Winnipeg, MB,
Canada. Reference powdered milk, human milk (HM), and formula samples were weighed and acid-digested prior to analysis by
graphite furnace atomic absorption spectroscopy. Mo content in all formulas ranged from 15.4 to 80.3 μg/L (mean ± SE, 37.7 ± 1.7 μg/L).
HM Mo concentration ranged from 1.5 to 9.5 μg/L (5.09 ± 0.81 μg/L). Formulas intended for full-term or for premature infants
feeding contained, on average, more Mo than HM. Formulas intended for infants with special needs contained similar mean Mo
levels to HM. No significant differences were detected between mean Mo values of formulas of a same type purchased from different
brands and/or at different locations. High Mo intake may pose health risks, despite lower bioavailability of Mo from formula
compared with HM. 相似文献
18.
Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anaesthetized individuals at Svalbard, Norway, were analysed for cadmium and total mercury. The mean level
of cadmium was 0.860 ± 0.321 μg/g dry weight (median = 0.811, range = 0.349–1.51 μg/g dry weight) and the mean level of mercury
was 0.235 ± 0.100 μg/g dry weight (median = 0.251, range = 0.121–0.424 μg/g dry weight). Levels of cadmium and mercury in
hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively
low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine
species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels at Svalbard are
lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses.
In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible
to collect hair from anaesthetized individuals or at the haul-out sites during moult, to monitor heavy metal levels of the
population.
Accepted: 6 December 1998 相似文献
19.
Akula Ramakrishna Parvatam Giridhar Gokare Aswathanarayana Ravishankar 《In vitro cellular & developmental biology. Plant》2011,47(6):667-673
High-frequency somatic embryogenesis was achieved in Coffea canephora using calcium ionophore A23187, which influences the influx of calcium into a cell. With 100 μM calcium ionophore and 5 mM
calcium, 85% and 70% of cultures produced embryogenic tissue, with 105 ± 7 and 95 ± 8 primary embryos from each callus mass
respectively. Medium supplemented with 100 μM EGTA (calcium chelator) or 1 mM verapamil (calcium channel blocker) significantly
reduced somatic embryogenesis. Calcium imaging studies were done to determine the relationship between morphogenetic response
and the cellular calcium levels. The calcium ionophore/calcium treatment was very effective in driving cellular machinery
toward embryogenesis. The embryos were regenerated into plantlets when cultured on MS medium supplemented with 5 mM calcium/100 μM
calcium ionophore A23187. Somatic embryogenesis-derived plants were successfully transferred to soil and grown to maturity
in the field. 相似文献
20.
SO3 belongs to the O-superfamily of conotoxins and is known to have analgesic effects in experimental animals. In order to
explore the mechanism of its potential pharmacological actions, the effect of SO3 on synchronized spontaneous calcium spikes
was examined in cultured hippocampal networks by calcium imaging. Spontaneous oscillations of intracellular concentrations
of calcium (Ca2+) in the form of waves and spikes are found in cultured hippocampal networks. Exposure to increasing concentrations of SO3
resulted in a progressive decrease in synchronized spontaneous calcium spikes. The higher concentrations (0.1 μmol/L and 1 μmol/L)
of SO3 showed the strongest inhibition. The rank order of inhibition was 1 μmol/L > 0.1 μmol/L > 10 μmol/L > 0.01 μmol/L.
This action of SO3 in reducing synchronized calcium spikes suggests a possible application for therapeutic treatment of epilepsy. 相似文献