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1.
Bogumiła Pilarczyk Aleksandra Balicka-Ramisz Alojzy Ramisz Ewa Adamowicz Renata Pilarczyk Agnieszka Tomza-Marciniak Małgorzata Bąkowska 《European Journal of Wildlife Research》2009,55(3):279-283
The aim of this study was to determine concentrations of selenium in the liver and kidneys of roe deer and red deer from West
Pomerania, depending on the season. Altogether, samples from 169 animals were collected (96 from roe deer and 73 from red
deer) in 2003–2007. The mean concentration of selenium in the liver of red deer and roe deer was 0.37 μg/g and 0.62 μg/g dry
weight, respectively. In kidneys, Se concentration was 2.72 μg/g d.w. in red deer and 2.99 μg/g d.w. in roe deer. In roe deer,
liver selenium concentration in autumn was significantly higher than in winter (P < 0.05) and spring (P < 0.01) and significantly lower in spring than in summer (P < 0.05); likewise, kidney selenium concentration was higher in autumn than in summer. In deer, no statistically significant
season-related differences were observed for liver selenium concentrations. In red deer kidneys, selenium concentration was
the lowest in summer, significantly lower than in autumn and winter. Low selenium concentrations in the analyzed tissues show
that the animals live in areas deficient in this element. 相似文献
2.
3.
Bogumiła Pilarczyk Agnieszka Tomza-Marciniak Renata Pilarczyk Diana Hendzel Barbara Błaszczyk Małgorzata Bąkowska 《Biological trace element research》2011,140(3):299-307
The aim of the study was to compare selenium concentrations in different organs of roe deer from northwestern Poland. Samples
of liver, kidneys, heart and lungs, collected from 74 roe deer shot during the hunting seasons of 2008–2009 in northwestern
Poland, were studied. Selenium concentration in the organs was determined spectrofluorimetrically. Mean selenium concentration
was 0.06 μg/g w.w. in the liver, 0.41 μg/g w.w. in the kidneys and 0.05 μg/g w.w. in the heart and lungs. Season had a significant
effect on selenium concentration in the liver, kidneys, lungs and heart. In all the organs, the highest selenium concentration
was found in spring and the lowest in autumn and winter. All animals studied were deficient in selenium. The low selenium
concentration in the liver or heart can disturb their function, and in the future, it may be a factor contributing to the
population decline of roe deer in the northwestern part of Poland. 相似文献
4.
Huawei Zeng Eric O. Uthus Sharon A. Ross Cindy D. Davis 《Biological trace element research》2009,131(1):71-80
Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon
cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se.
The present study was designed to determine whether dietary selenite affects somatic mutation frequency in vivo. We used the
Big Blue transgenic model to evaluate the in vivo mutation frequency of the cII gene in rats fed either a Se-deficient (0 μg Se/g diet) or Se-supplemented diet (0.2 or 2 μg Se/g diet; n = 3 rats/diet in experiment 1 and n = 5 rats/group in experiment 2) and injected with DMH (25 mg/kg body weight, i.p.). There were no significant differences
in body weight between the Se-deficient and Se-supplemented (0.2 or 2 μg Se/g diet) rats, but the activities of liver glutathione
peroxidase and thioredoxin reductase and concentration of liver Se were significantly lower (p < 0.0001) in Se-deficient rats compared to rats supplemented with Se. We found no effect of dietary Se on liver 8-hydroxy-2′-deoxyguanosine.
Gene mutation frequency was significantly lower in liver (p < 0.001) than that of colon regardless of dietary Se. However, there were no differences in gene mutation frequency in DNA
from colon mucosa or liver from rats fed the Se-deficient diet compared to those fed the Se-supplemented (0.2 or 2 μg Se/g
diet) diet. Although gene mutations have been implicated in the etiology of cancer, our data suggest that decreasing gene
mutation is not likely a key mechanism through which dietary selenite exerts its anticancer action against DMH-induced preneoplastic
colon cancer lesions in a Big Blue transgenic rat model.
The US Department of Agriculture, Agricultural Research Service, Northern Plains Area, is an equal opportunity/affirmative
action employer and all agency services are available without discrimination.
Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department
of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.
This work was supported by the US Department of Agriculture and National Cancer Institute. 相似文献
5.
Michael A. Pfaller Daniel J. Diekema Mariana Castanheira Ronald N. Jones 《Current fungal infection reports》2011,5(3):120-127
Antifungal susceptibility testing of Candida against the echinocandin antifungal agents (anidulafungin [ANF], caspofungin [CSF], micafungin [MCF]) has been standardized
by the Clinical and Laboratory Standards Institute (CLSI) Subcommittee on Antifungal Testing. The CLSI proposed a single set
of clinical breakpoints (CBPs) for all three echinocandins and all species of Candida: susceptible, minimum inhibitory concentration (MIC) ≤ 2 μg/mL; nonsusceptible, MIC > 2 μg/mL. Subsequently, these CBPs have
been shown to lack sensitivity in detecting strains of Candida with acquired resistance mechanisms associated with treatment failure. Studies using the CLSI method have defined wild-type
(WT) MIC distributions and epidemiologic cutoff values (ECVs) for each echinocandin and the common species of Candida. The ECVs serve as a sensitive means of discriminating WT strains from those with acquired resistance mechanisms. WT MIC
distributions revealed ECV ranges of 0.03 to 0.25 μg/mL for all major species except C. parapsilosis (1–4 μg/mL) and C. guilliermondii (4–16 μg/mL). These ECVs reliably differentiate WT strains of each species from non-WT strains containing fks mutations. These data, coupled with additional biochemical, clinical, pharmacokinetic, and pharmacodynamic considerations,
have resulted in new CBPs of ≤0.25 μg/mL (susceptible), 0.5 μg/mL (intermediate), and ≥1 μg/mL (resistant) for ANF, CSF, and
MCF for C. albicans, C. tropicalis, and C. krusei. For these agents and C. parapsilosis, the new CBPs are ≤2 μg/mL (susceptible), 4 μg/mL (intermediate), and ≥8 μg/mL (resistant). For C. glabrata, the CBPs for ANF and CSF are ≤0.12 μg/mL (susceptible), 0.25 μg/mL (intermediate), and ≥0.5 μg/mL (resistant), whereas those
for MCF are ≤0.06 μg/mL, 0.12 μg/mL, and ≥0.25 μg/mL, respectively. Application of both ECVs and the lower species-specific
CBPs for the echinocandins has proven useful in both resistance surveillance and clinical care and will serve as an important
step in international harmonization of in vitro susceptibility testing of this important antifungal class. 相似文献
6.
Letsiou S Nomikos T Panagiotakos D Pergantis SA Fragopoulou E Antonopoulou S Pitsavos C Stefanadis C 《Biological trace element research》2009,128(1):8-17
The trace element selenium is an essential micronutrient for human health and its low levels in serum are implicated in the
pathogenesis of several chronic diseases. Therefore, the determination of total selenium in serum may contribute to the assessment
of the health and nutritional status of certain populations. The objective of the present work was to determine total selenium
in the serum of 506 healthy volunteers that participated in the ATTICA study. Selenium was determined in serum by using the
technique of inductively coupled plasma mass spectrometry. The mean serum selenium concentration was determined to be 91.8 ± 33.7 μg/L
(N = 506); 87.6% of women and 88.5% of men had serum selenium concentration below 125 μg/L, the cutoff considered to be required
for optimal glutathione peroxidase activity. No association was found between serum selenium levels and the gender of the
participants while a significant decline of selenium with age (p < 0.0001) was observed. According to our results, no anthropometric, lifestyle, nutritional, or biochemical indices were
able to affect the association between serum selenium and age. This result may indicate that other factors such as selenium
distribution as well as retention may be affecting the relationship between serum selenium and age. 相似文献
7.
Shahzad Z. Iqbal R. Russell M. Paterson Ijaz A. Bhatti Muhammad R. Asi Munir A. Sheikh Haq N. Bhatti 《Mycotoxin Research》2010,26(3):205-209
The occurrence of aflatoxin B1 (AFB1) in chilies from Pakistan was determined by using HPLC in work undertaken in Pakistan.
Whole (n = 22) and powdered (n = 22) chilies were analyzed. Sixteen (73.0%) and 19 (86.4%) samples of whole and ground chilies, respectively, were contaminated.
The mean concentration in powdered chilies (32.20 μg/kg) was higher statistically than in whole chilies (24.69 μg/kg). Concentrations
ranged from 0.00 to 89.56 μg/kg for powdered chilies, compared with 0.00–96.3 μg/kg for whole chilies. The limits of detection
and quantification were 0.05 μg/kg and 0.53 μg/kg, respectively. The concentrations were high in general and greater than
the statutory limit set by the European Union. There is considerable scope for improvements in chili production in Pakistan. 相似文献
8.
Characteristics of Se-Enriched Mycelia by Stropharia rugoso-annulata and its Antioxidant Activities in vivo 总被引:1,自引:0,他引:1
Zhen Song Le Jia Feng Xu Fanyun Meng Peng Deng Keming Fan Xiaonan Liu 《Biological trace element research》2009,131(1):81-89
Selenium (Se) is an essential trace element for humans and animals. Stropharia rugoso-annulata is a nutritional and functional mushroom containing many kinds of bioactive ingredients. The aims of this study were to investigate
the Se-enrichment characteristics of S. rugoso-annulata in submerged culture and evaluate the antioxidant activities of Se-enriched mycelia in vivo in terms of the values of glutathione
peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA). The optimum parameters of Se-enrichment under
the optimal Se concentration (150 μg/mL) in media were as follows: biomass 8.11 ± 0.25 g/L, Se content in mycelia 4,727.68 ± 13 μg/g,
Se-accumulated rate 24.68 ± 1.67%, and percentage of organic Se 96.27 ± 3.26%. The mainly subsistent forms of selenium in
Se-enriched mycelia were selenoprotein and selenium-polysaccharide. The contents of total amino acids (TAA) and essential
amino acids (EAA) in Se-enriched mycelia were increased by 13.5 ± 1.09% and 12.8 ± 0.89%, respectively. It was efficient for
Se-enriched mycelia to elevate GSH-Px and SOD activities and decrease MDA content. These results indicated that Se-enriched
mycelia of S. rugoso-annulata represent a novel dietary source of bioavailable supplemental selenium. 相似文献
9.
Selenium-enriched tea was suggested as a possible source of supplemental Se. The result of this study indicates that it is
not practicable to make selenium-enriched tea as a beverage like traditional green tea or black tea for the supplementation
of selenium in human diet. The selenium dispersibilities of fresh tea leaves, green tea, and black tea highly correlated with
those of protein (r
2 = 0.998). The high protein dispersibility (85.0%) of fresh tea leaves in water solution was accompanied by that of selenium
(93.8%). Decreases in protein dispersibility of green tea and black tea to 2.5% and 4.2 % coincided with those of selenium
to only 8.3% and 10.1%, respectively. The amount (14.90 μg) of selenium in saturated ammonium sulphate (a protein precipitating
reagent) precipitate was 83.8% of that (17.79 μg) in fresh tea leaf extract, and after the saturated ammonium sulphate precipitate
was dialyzed against distilled water overnight, the amount (14.37 μg) of selenium remaining in the dialyzed precipitate (protein)
was still 80.8% of that in the fresh tea leaf extract. However, there were no significant differences (p > 0.05) between the amount of selenium in the saturated ammonium sulphate precipitate and that in the saturated ammonium
sulphate precipitate that was dialyzed. 相似文献
10.
Nisianakis P Giannenas I Gavriil A Kontopidis G Kyriazakis I 《Biological trace element research》2009,128(1):62-71
The effect of two different doses of selenium [1 and 50 μg selenium/100 g body weight (wt)] on nicotine-induced oxidative
damage in liver was investigated in experimental rats. Male albino rats were maintained for 60 days as follows: (1) control
group (normal diet), (2) nicotine group (0.6 mg/kg body wt)/day, (3) high-dose selenium (50 μg/100 g body wt)/day, (4) high-dose
selenium (50 μg/100 g body wt) + nicotine (0.6 mg/kg body wt)/day, (5) low-dose selenium (1 μg/100 g body wt)/day, and (6)
low-dose selenium (1 μg/100 g body wt) + nicotine (0.6 mg/kg body wt)/day. Nicotine administration caused a decrease in the
activity of antioxidant enzymes, an increase in the concentration of lipid peroxidation products and protein carbonyls and
an increase in the activity of nitric oxide synthase compared to the control group. Coadministration of nicotine and selenium
reduced the concentration of lipid peroxidation products and increased the activity of antioxidant enzymes compared to the
nicotine group. Selenium also enhanced the metabolism of nicotine. The antioxidant effect was more significant in the group
administered a low dose of selenium. 相似文献
11.
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
12.
Valsartan orodispersible tablets have been developed at 40-mg dose, with the intention of facilitating administration to patients
experiencing problems with swallowing and hopefully, improving its poor oral bioavailability. Work started with selecting
drug compatible excipients depending on differential scanning calorimetric analysis. A 33 full factorial design was adopted for the optimization of the tablets prepared by freeze-drying technique. The effects of
the filler type, the binder type, and the binder concentration were studied. The different tablet formulas were characterized
for their physical properties, weight variation, disintegration time, surface properties, wetting properties, and in vitro dissolution. Amongst the prepared 27 tablet formulas, formula number 6 (consisting of 4:6 valsartan:mannitol and 2% pectin)
was selected to be tested in vivo. Oral bioavailability of two 40 mg valsartan orodispersible tablets was compared to the conventional commercial tablets after
administration of a single dose to four healthy volunteers. Valsartan was monitored in plasma by high-performance liquid chromatography.
The apparent rate of absorption of valsartan from the prepared tablets (C
max = 2.879 μg/ml, t
max = 1.08 h) was significantly higher than that of the conventional tablets (C
max = 1.471 μg/ml, t
max = 2.17 h), P ≤ 0.05. The relative bioavailability calculated as the ratio of mean total area under the plasma concentration–time curve
for the orodispersible tablets relative to the conventional ones was 135%. The results of the in vivo study revealed that valsartan orodispersible tablets would be advantageous with regards to improved patient compliance, rapid
onset of action, and increase in bioavailability. 相似文献
13.
Toghyani M Toghyani M Shivazad M Gheisari A Bahadoran R 《Biological trace element research》2012,146(2):171-180
This study was conducted to determine the effects of dietary supplementation with Cr nicotinate and Cr chloride and their
optimum inclusion rate on performance, carcass traits, meat oxidative stability, serum metabolites, hematological parameters,
and liver chromium concentration in heat-stressed broilers. A total number of 420, 1-day-old male broiler chicks were randomly
assigned to seven treatments with four replicates of 15 chicks. The dietary treatments consisted of the basal diet supplemented
with 0 (control), 500, 1,000, and 1,500 μg/kg Cr in the form of Cr nicotinate and Cr chloride. Chicks were raised for 6 weeks
in heat stress condition (33 ± 2°C). Supplements of organic and inorganic Cr particularly at 1,500 μg/kg incorporation increased
feed consumption (P < 0.05) and body mass gain of broilers (P < 0.01). Cr supplementation increased carcass yield and decreased abdominal fat (P < 0.01). Supplementation of 1,500 μg/kg Cr nicotinate (P < 0.05) enhanced liver Cr concentration. Storage time increased lipid oxidation of meat (P < 0.01). Cr decreased lipid oxidation of breast and thigh muscles over 2 (P < 0.01) or 6 (P < 0.05) days of storage time. Birds fed 1,500 μg/kg Cr nicotinate, had lower concentration of serum glucose and triglyceride
at 21 days (P < 0.05). Hematological parameters tested at 21 and 42 days, were not influenced. The results suggested that dietary Cr supplementation
regardless of its source have a positive effect on productive, and carcass traits, also enhances oxidative stability of refrigerated
meat in broilers reared under heat stress conditions. 相似文献
14.
Sevcikova L Pechova A Pavlata L Antos D Mala E Palenik T Panev A Dvorak R 《Biological trace element research》2011,143(2):882-892
The aim of this trial was to compare the effect of long-term supplementation of goats with different forms of selenium on
body reserves of selenium in their kids at the time of weaning. Thirty-three pregnant goats were divided into five groups.
Group C was control while the other four groups were supplemented with selenium (Se) for 6 weeks before parturition (0.3 mg/goat/day)
and after parturition (0.9 mg/goat/day). Group “Se-I” received sodium selenite and three other groups received organic forms:
“Se-L,” lactate–protein complex; “Se-P,” Se-proteinate; and “Se-Y,” Se-yeast. The kids were weaned at 3 months of age and
samples of tissues (liver, pancreas, myocardium, lungs, kidneys, spleen, thigh, tongue, and diaphragm) were taken after slaughtering.
The long-term supplementation of goats with Se influenced Se concentration in all examined tissues of kids. Significant differences
(p ≤ 0.01) were found between the control and all experimental groups, except for the renal cortex and pancreas (Se-I). The
average increase of Se concentration in overall examined tissues in comparison with the control (100%) was as follows: Se-Y,
192%; Se-P, 167%; Se-L, 161%; Se-I, 144%. The highest efficiency was found in the group supplemented with Se-yeast with a
high content of selenomethionine, also the other two organic forms of Se were more efficient than the inorganic form. 相似文献
15.
The Alternaria mycotoxin tenuazonic acid (TA) was quantified in fruit juices (n = 50), cereals (n = 12) and spices (n = 38) using a recently developed stable isotope dilution assay (SIDA). [13 C6,15 N]-TA was used as the internal standard. Method validation revealed low limits of detection (LODs) of 0.15 μg/kg (fruit juices),
1.0 μg/kg (cereals) and 17 μg/kg (spices). The respective limits of quantitation were about three times higher. Recovery was
about 100% for all matrices. The precision (relative standard deviation of replicate analyses of naturally contaminated samples)
was 4.2% (grape juice; 1.7 μg/kg), 3.5% (whole wheat flour; 36 μg/kg) and 0.9% (curry powder; 215 μg/kg). The median content
of TA in the analyzed samples was 1.8 μg/kg (fruit juices), 16 μg/kg (cereals) and 500 μg/kg (spices). Positive samples amounted
to 86% (fruit juices), 92% (cereals) and 87% (spices). 相似文献
16.
Shariati F Esaili Sari A Mashinchian A Pourkazemi M 《Biological trace element research》2011,143(1):281-291
Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l−1) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and
gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol
measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the
cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and
gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l−1 Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients
showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills.
Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination. 相似文献
17.
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
18.
Alma E. Rodriguez Estrada Hyun-Ju Lee Robert B. Beelman Maria del Mar Jimenez-Gasco Daniel J. Royse 《World journal of microbiology & biotechnology》2009,25(9):1597-1607
Antioxidants are molecules that may reverse, prevent or slow cellular damage caused by free radicals. Increasing dietary intake
of antioxidants is thought to reduce oxidative stress that may contribute to the development of several diseases. Mushrooms
are known to contain antioxidants such as selenium, ergothioneine and phenolics that may serve this role. Here we sought to
enhance selenium and ergothioneine concentration in Pleurotus eryngii var. eryngii basidiomata by modifying the techniques used for their commercial cultivation. To enhance selenium content in mushrooms,
substrates were supplemented with sodium selenite (Na2SeO3) to reach selenium concentrations of 5 and 10 μg/g. Basidiomata of one commercial isolate (WC888) accumulated selenium up
to 4.6 and 9.3 μg/g (d.w.), respectively. Therefore, a serving size (85 g) of fresh P. eryngii mushrooms produced on substrates supplemented with 5 and 10 μg/g of Na2SeO3 would supply 70.4 and 116.3% of the daily value of selenium (DV = 70 μg), respectively. Since selenium-enriched mushrooms
would supply more than 20% of the DV, they could be considered an excellent source of selenium. Ergothioneine concentration
was enhanced in mushrooms produced on low-moisture (55%) substrate compared to the commonly used 60% (high-moisture) in commercial
cultivation. Mushrooms produced on low-moisture substrate had ergothioneine concentrations of 3.0 mg/g, while mushrooms produced
on high-moisture substrate contained 2.2 mg/g or less. Use of a casing overlay for mushroom production resulted in significant
yield increases on low-moisture substrate but not on high-moisture substrate. 相似文献
19.
Cadmium and mercury concentrations were measured in the tissues of 64 individual albatrosses [23 wandering albatrosses (Diomedea exulans), 9 royal albatrosses (Diomedea epomophora) and 32 shy albatrosses (Thalassarche cauta)] which were killed as by-catch in longline fishing activities between 1991 and 1994. Mercury concentrations were also determined
for 33 shy albatross eggs (excluding shells). The birds were all sexed and assigned to one of two age classes (immature and
adult). The three species exhibited differences both in overall concentrations of cadmium and mercury, and also in the pattern
of accumulation of metals with age and sex. Wandering albatrosses exhibited the highest mercury concentrations with a mean
concentration in adult liver samples of 920.0 ± 794.1 μg g−1 dry weight. Shy albatrosses had the lowest mercury concentrations with mean concentrations in adult livers of 36.3 ± 21.4 mg
g−1 dry weight. The highest mercury concentration was 1800 μg g−1 for an adult female wandering albatross. Cadmium concentrations were less variable, with adult royal albatrosses having the
highest average concentrations (180.0 ± 165.0 in adult kidneys) and adult shy albatrosses the lowest (40.1 ± 20.0 in adult
kidney). The highest individual cadmium concentration was 287 μg g−1 for a juvenile wandering albatross. There was no evidence of increased accumulation of cadmium with age in any of the species,
but wandering albatrosses showed higher mercury concentrations in adults than juveniles. Female wandering albatrosses also
had significantly higher mercury concentrations than males. The mercury contents of the shy albatross eggs were very low,
with a maximum concentration of 5.4 μg g−1. The results of this study are consistent with the findings of previous work on albatrosses and support the notion that the
life-history strategy of these species (i.e. long-lived with low reproductive output) may be an important determinant in the
concentrations of some metals found in their tissues.
Accepted: 15 February 1999 相似文献
20.
S. A. Webster S. A. Mitchell W. A. Gallimore L. A. D. Williams M. H. Ahmad 《In vitro cellular & developmental biology. Plant》2008,44(2):112-118
A procedure for producing somatic embryos enriched with dibenzyl trisulfide (DTS) using a hormone-dependent culture system
is reported for Petiveria alliacea L. (Guinea hen weed). Leaf explants were cultured on a Murashige and Skoog medium supplemented with a range of naphthaleneacetic
acid (NAA) concentrations and a fixed concentration of benzyladenine (BAP) at 11.0 μM and sucrose or glucose at 30 g l−1. Leaf explants cultured on all media types started to form callus at the cut surfaces of the discs 10–14 d after initiation.
The type of sugar used influenced average fresh weight, the propensity to form roots, as well as the embryogenic response.
The highest mean fresh weight (337.7 ± 26.18 mg) and mean root number (23.7 ± 1.69) was produced on media enriched with sucrose
and supplemented with 53.7 μM NAA and 11.0 μM BAP. An ethanol extract of rhizogenic/embryogenic callus or somatic embryos
was subjected to high-performance liquid chromatography analysis, which revealed the presence of DTS in both extracts. UV
spectral analysis and the use of standard quantitation procedures showed that the quantity of DTS in the somatic embryo extract,
at 0.16% (w/v), was approximately 30-fold higher than in rhizogenic/embryogenic callus (0.0055% w/v) of similar fresh weight. These results indicate that it is possible to biosynthesize approximately 6 mg of natural DTS from
3,808 mg of fresh somatic embryos within 10 wk from less than three leaf explants. 相似文献