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1.
M. A. Norouzian 《Biological trace element research》2011,139(2):160-167
Relation between iodine (I) intake by lactating Holstein cows and iodine concentrations in raw and pasteurized milk were investigated.
Four treatment groups with eight cows assigned to each treatment were fed a basal diet containing 0.534 mg I/kg alone or supplemented
with potassium iodide at 2.5, 5 or 7.5 mg/kg in 7-week period. Iodine concentrations in raw milk increased with each increase
in dietary I from 162.2 ng/ml for basal diet to 534.5, 559.8 and 607.5 ng/ml when 2.5, 5 and 7.5 mg/kg was fed as potassium
iodide (P < 0.05). This trend was found for blood plasma and urine iodine concentration. Iodine supplementation had no significant
effect on thyroidal hormones. high-temperature short-time (HTST) pasteurization process reduced I concentration. The mean
iodine content found in the milk prior to heating processing was 466.0 ± 205.0 ng/ml, whereas for the processed milk this
level was 349.5 ± 172.8 ng/ml. It was concluded that iodine supplementation above of NRC recommendation (0.5 mg/kg diet DM)
resulted in significant increases in iodine concentrations in milk, although the effect of heating in HTST pasteurization
process on iodine concentration was not negligible. 相似文献
2.
Influence of different periods of exposure to hot environment on rumen function and diet digestibility in sheep 总被引:2,自引:0,他引:2
U. Bernabucci N. Lacetera P. P. Danieli P. Bani A. Nardone B. Ronchi 《International journal of biometeorology》2009,53(5):387-395
Effects of different periods of exposure to hot environments on rumen function, diet digestibility and digesta passage rate
were studied in four adult not-pregnant Sardinian ewes housed in a climatic chamber. The ewes were kept in individual metabolic
cages. The trial lasted 83 days; 17 days were spent under thermal comfort conditions (TC) [temperature-humidity index (THI) = 65.0 ± 2.0],
followed by 49 days under elevated THI (ETHI: THI = 82.0 ± 2.5) and 17 days under thermal comfort (TC; THI = 65.0 ± 1.0).
Five digestibility and passage rate trials were carried out during the 83 days. Trials 1 and 5 were carried out under TC;
trials 2, 3 and 4 were carried out under ETHI. Values of rectal temperatures (39.7 ± 0.3°C) and respiratory rate (118.4 ± 31.8
breaths/min) indicated that sheep under ETHI were heat-stressed. Heat stress caused an increase (P < 0.01) in water intake, and reductions (P < 0.05) in dry matter intake, rumen pH, rumen cellulolytic and amylolytic bacteria count, rumen osmolarity, organic matter,
dry matter, neutral detergent fibre, acid detergent fibre and non-structural carbohydrates digestibility coefficients, and
a reduction of digesta passage rates. Under ETHI, diet digestibility and passage rate of digesta were reduced in a time-dependent
fashion. Variation of diet digestibility under ETHI was not related to passage rate of digesta and feed intake. Reduction
of cellulolytic and amylolytic bacteria and the adaptive response to hot environment seem to be related to alteration of digestibility
observed in ewes chronically exposed to hot environment. 相似文献
3.
Ozdemir HS Karadas F Pappas AC Cassey P Oto G Tuncer O 《Biological trace element research》2008,122(3):206-215
The objective of the present study is to calculate linear regressions between a mother and her child with respect to their
selenium concentration (ng/g) in the following traits: maternal blood and umbilical cord blood, maternal and child hair, maternal
milk and child umbilical cord blood, maternal milk and meconium, maternal blood plasma, and child meconium. The data were
collected at Research Hospital of the University of Yüzüncü Yıl from 30 pairs of mothers and their newborn baby. The mean
maternal serum Se level in 30 mothers was 68.52 ± 3.57 ng/g and cord plasma level was 119.90 ± 18.08 ng/g. The Se concentration
in maternal and neonatal hair was 330.84 ± 39.03 and 1,124.76 ± 186.84 ng/g, respectively. The Se concentration of maternal
milk at day 14 after delivery was determined as 68.63 ± 7.78 ng/g (n = 13) and the concentration of Se was 418.90 ± 45.49 ng/g (n = 22) for meconium of neonatal. There was no significant difference between maternal blood and milk Se levels. However, hair
Se concentration was significantly higher than milk and maternal blood Se level. For each trait comparison, the average absolute
difference in log10-transformed Se concentration was calculated between a mother and her child. The observed average absolute difference was
compared with a test distribution of 1,000 resampled bootstrap averages where the number of samples was maintained but the
relationship between a mother and her child was randomized among samples (α = 0.05). 相似文献
4.
Maria A. Karatzia Konstantinos Pourliotis Panagiotis D. Katsoulos Harilaos Karatzias 《Biological trace element research》2011,142(2):159-166
The experiment investigated the effects of the dietary inclusion of 200 g of the natural zeolite, clinoptilolite on the blood
serum concentrations of aluminium (Al) and inorganic phosphorus (P) as well as on the ruminal pH and the ruminal concentrations
of Al and P and of certain volatile fatty acids. Sixteen Holstein cows with a rumen fistula were randomly assigned to one
of two groups. Group A cows (n = 8) were fed the basal ration supplemented with 200 g of clinoptilolite per day, and group B cows (n = 8) were fed the basal ration and served as controls. Blood and rumen fluid samples were collected at the same day of each
week and at the same time (5 h after morning feeding) for 12 weeks. Clinoptilolite supplementation had no significant effect
on ruminal and blood serum concentrations of Al and P. However, clinoptilolite significantly increased ruminal pH and acetate,
and decreased ruminal propionate and valerate. 相似文献
5.
Muhammad Akram Matiullah Arshid Iqbal S. N. Husaini Fariha Malik 《Biological trace element research》2011,139(3):287-295
Intake of boron from food and drinking water may pose a risk to the public health above a certain concentration level. Therefore,
knowledge of boron concentration in drinking water and food items is essential. In this context, samples of drinking water
were collected from natural springs of the Neelum valley, Azad Kashmir, hit by devastating earthquake in 2005. In these samples,
boron concentration was determined using neutron-induced radiography technique. To do so, unknown water samples, along with
standard of known boron dried on CR-39 detectors, were irradiated with thermal neutrons. After exposure, CR-39 detectors were
etched in 6 M NaOH at 70°C. The tracks produced due to the alpha particles and 7Li ions as a result of 10B(n,α)7Li reaction were counted under an optical microscope. The tracks produced in theses samples were then related to the boron
contents. The measured boron concentration in water samples was found to vary from 0.105 ± 0.005 to 0.247 ± 0.013 mg/l with
an average value of 0.17 ± 0.04 mg/l, which are within the acceptable limits. 相似文献
6.
《Animal : an international journal of animal bioscience》2019,13(4):750-759
Vitamin B12 is synthesised in the rumen from cobalt (Co) and has a major role in metabolism in the peri-paturient period, although few studies have evaluated the effect of the dietary inclusion of Co, vitamin B12 or injecting vitamin B12 on the metabolism, health and performance of high yielding dairy cows. A total of 56 Holstein-Friesian dairy cows received one of four treatments from 8 weeks before calving to 8 weeks post-calving: C, no added Co; DC, additional 0.2 mg Co/kg dry matter (DM); DB, additional 0.68 mg vitamin B12/kg DM; IB, intra-muscular injection of vitamin B12 to supply 0.71 mg/cow per day prepartum and 1.42 mg/cow per day post-partum. The basal and lactation rations both contained 0.21 mg Co/kg DM. Cows were weighed and condition scored at drying off, 4 weeks before calving, within 24 h of calving and at 2, 4 and 8 weeks post-calving, with blood samples collected at drying off, 2 weeks pre-calving, calving and 2, 4 and 8 weeks post-calving. Liver biopsy samples were collected from all animals at drying off and 4 weeks post-calving. Live weight changed with time, but there was no effect of treatment (P>0.05), whereas cows receiving IB had the lowest mean body condition score and DB the highest (P<0.05). There was no effect of treatment on post-partum DM intake, milk yield or milk fat concentration (P>0.05) with mean values of 21.6 kg/day, 39.6 kg/day and 40.4 g/kg, respectively. Cows receiving IB had a higher plasma vitamin B12 concentration than those receiving any of the other treatments (P<0.001), but there was no effect (P>0.05) of treatment on homocysteine or succinate concentrations, although mean plasma methylmalonic acid concentrations were lower (P=0.019) for cows receiving IB than for Control cows. Plasma β-hydroxybutyrate concentrations increased sharply at calving followed by a decline, but there was no effect of treatment. Similarly, there was no effect (P>0.05) of treatment on plasma non-esterified fatty acids or glucose. Whole tract digestibility of DM and fibre measured at week 7 of lactation were similar between treatments, and there was little effect of treatment on the milk fatty acid profile except for C15:0, which was lower in cows receiving DC than IB (P<0.05). It is concluded that a basal dietary concentration of 0.21 mg Co/kg DM is sufficient to meet the requirements of high yielding dairy cows during the transition period, and there is little benefit from additional Co or vitamin B12. 相似文献
7.
Selenium Distribution in Camel Blood and Organs After Different Level of Dietary Selenium Supplementation 总被引:1,自引:0,他引:1
Rabiha Seboussi Bernard Faye Ghaleb Alhadrami Mustafa Askar Wissam Ibrahim Baaha Mahjoub Khalil Hassan Tarik Moustafa Ahmed Elkhouly 《Biological trace element research》2010,133(1):34-50
Eight young female camels shared in four groups of two 2 years received a basal diet enriched respectively with 0, 2, 4, and
8 mg selenium under sodium selenite form for 64 days. Feed intake was assessed daily; blood samples were taken on weekly basis.
One camel from each group was killed at the end of the experiment. Se concentration in serum was increased significantly in
the supplemented groups with an average of 176.3 ± 18.0 ng/mL in the control group, 382.7 ± 107.6 in the group receiving 2 mg
Se, 519.8 ± 168.4 in the group receiving 4 mg Se, and 533.4 ± 158.6 in the group receiving 8 mg Se daily. For glutathione
peroxidase (GSH-Px) activity, the control group (51.0 IU/g Hb) and the group receiving 2 mg (50.5 IU/g Hb) were significantly
different than groups receiving 4 and 8 mg (respectively, 65.9 and 76.1 IU/g Hb). No significant variation occurred for vitamin
E (mean, 0.56 ± 0.23 ng/mL). Significant correlation between serum Se and GSH-Px was reported. Kidney was the richest organ
in selenium followed by lung, spleen, and liver, but the increase in supplemented groups was more marked in liver and kidney.
The hair seemed to be the best indicator of selenium intake in camel. 相似文献
8.
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
9.
Salehifar E Shokrzadeh M Ghaemian A Aliakbari S Saeedi Saravi SS 《Biological trace element research》2008,125(2):97-108
Changes in the cupper (Cu) and zinc (Zn) concentrations have been reported previously in idiopathic dilated cardiomyopathy
(IDCMP). As a result of controversial results, the aim of this study was to compare the Zn and Cu concentrations and Zn/Cu
ratio of IDCMP patients to healthy volunteers. In addition, the correlation of Cu and Zn levels with age has been evaluated.
The study population consisted of 18 IDCMP patients and 27 healthy volunteers. IDCMP patients had normal angiography with
echocardiography supporting cardiomyopathy without pericardial and valvular diseases. Exclusion criteria were renal or hepatic
insufficiency, alcohol usage, and intake of supplements containing Cu or Zn within 1 week ago. Cu and Zn levels have been
assayed with atomic absorption spectrophotometry. Statistical analysis was performed with SPSS 10 software with independent
sample t test for comparing the level of Cu and Zn of IDCMP patients with normal subjects and Pearson correlation to determine the
correlation between numeric data. P < 0.05 was considered as significant differences. There was a trend for a lower Zn level in IDCMP patients compared to healthy
volunteers. (0.97 ± 0.25 mg/l vs. 1.12 ± 0.42 mg/l, respectively). The mean Cu levels of IDCMP and normal subjects were 1.33 ± 0.20 mg/l
and 1.31 ± 0.23 mg/l, respectively. There was a significant difference in Zn/Cu ratio among patients based on the NYHA classification
of heart failure (P = 0.003). Age was negatively correlated with Zn levels in IDCMP group (P = 0.037) and positively with Cu levels in healthy volunteers (P = 0.012). A lower Zn level in IDCMP patients compared to healthy volunteers and specially a significant difference in Zn/Cu
ratio of patients based on their NYHA classification would suggest a critical role of zinc and Cu imbalance in development
of IDCMP. 相似文献
10.
Non-lactating dairy cattle were transitioned to a high-concentrate diet to investigate the effect of ruminal pH suppression,
commonly found in dairy cattle, on the density, diversity, and community structure of rumen methanogens, as well as the density
of rumen protozoa. Four ruminally cannulated cows were fed a hay diet and transitioned to a 65% grain and 35% hay diet. The
cattle were maintained on an high-concentrate diet for 3 weeks before the transition back to an hay diet, which was fed for
an additional 3 weeks. Rumen fluid and solids and fecal samples were obtained prior to feeding during weeks 0 (hay), 1, and
3 (high-concentrate), and 4 and 6 (hay). Subacute ruminal acidosis was induced during week 1. During week 3 of the experiment,
there was a significant increase in the number of protozoa present in the rumen fluid (P = 0.049) and rumen solids (P = 0.004), and a significant reduction in protozoa in the rumen fluid in week 6 (P = 0.003). No significant effect of diet on density of rumen methanogens was found in any samples, as determined by real-time
PCR. Clone libraries were constructed for weeks 0, 3, and 6, and the methanogen diversity of week 3 was found to differ from
week 6. Week 3 was also found to have a significantly altered methanogen community structure, compared to the other weeks.
Twenty-two unique 16S rRNA phylotypes were identified, three of which were found only during high-concentrate feeding, three
were found during both phases of hay feeding, and seven were found in all three clone libraries. The genus Methanobrevibacter comprised 99% of the clones present. The rumen fluid at weeks 0, 3, and 6 of all the animals was found to contain a type
A protozoal population. Ultimately, high-concentrate feeding did not significantly affect the density of rumen methanogens,
but did alter methanogen diversity and community structure, as well as protozoal density within the rumen of nonlactating
dairy cattle. Therefore, it may be necessary to monitor the rumen methanogen and protozoal communities of dairy cattle susceptible
to depressed pH when methane abatement strategies are being investigated. 相似文献
11.
Since genetic damage induced by ethanol exposure is controversial and incomplete and because germ and somatic cells constitute
bioindicators for monitoring reproductive toxicity and genotoxic actions of ethanol consumption, the purpose of the present
investigation was to evaluate morphological sperm, oocyte alterations and parental genotoxic effects after sub-chronic ethanol
intake in the CF-1 outbred mouse strain. Ethanol 10% was administered to CF-1 adult male (treated males, TM) and female (treated
females, TF) mice for 27 days, whereas water was given to controls from both sexes too (CM and CF). Post-treatment micronucleus
frequency (MN-PCE/1,000/mouse) and gamete morphology were evaluated. To test whether change of female reproductive status
results in maternal genotoxicity, CF-1 females received ethanol 10% (exposed group, periconceptionally treated females (PTF))
or water (control group, pregnant control females (PCF)) in drinking water for 17 days previous and up to 10 days of gestation.
TM had a high percentage of abnormal spermatozoa vs CM (p < 0.001) and elevated parthenogenetic activated oocyte frequency appeared in TF vs CF (p < 0.001). Sub-chronic ethanol ingestion induced increased MN frequency in TM and TF (p < 0.01). In PTF, where blood alcohol concentrations were between 19–28 mg/dl, very significantly increased MN frequency was
found vs PCF (p < 0.01), whereas MN values were similar to TF. These results show that sub-chronic alcohol ingestion in CF-1 mice produces
sperm head dysmorphogenesis and oocyte nuclear anomalies, suggesting that morphological abnormalities in germ cells are probably
related to parental genotoxicity after ethanol consumption. 相似文献
12.
The protective effects of melatonin, vitamin E, and selenium alone or in combination were tested against cadmium-induced oxidative
damage in rat testes. A total of 60 male rats were equally divided into five study groups, one of which acted as control receiving
subcutaneous injections of physiological saline. The remaining four groups were treated with subcutaneous injections of cadmium
chloride at a dose of 1 mg/kg weight. The first study group received no treatment. The second group was treated with a combination
of 60 mg/kg vitamin E and 1 mg/kg sodium selenite. Group 3 was treated with 10 mg/kg melatonin, and the fourth group received
a combination of vitamin E, sodium selenite, and melatonin at the doses mentioned above. After 1 month, the animals were killed,
and the testes were excised for histological inspection and determination of tissue malondialdehyde and the activity of superoxide
dismutase. The animals receiving no treatment showed significantly higher malondialdehyde levels and reduced activity of the
enzyme (p < 0.05). Treatment with antioxidants resulted in a significant reduction in malondialdehyde when compared to the nontreated
animals (p < 0.05) and an increase in the superoxide dismutase activity that was almost the same as the controls. The combination of
melatonin, vitamin E, and selenium appears to have the more profound effect against cadmium-induced testicular injury. 相似文献
13.
Seifi S Tabandeh MR Nazifi S Saeb M Shirian S Sarkoohi P 《Journal of physiology and biochemistry》2012,68(2):193-203
Available experimental data suggest that adiponectin and thyroid hormones have biological interaction in vivo. However, the
effects of thyroid hormones on adipose adiponectin gene expression in thyroid dysfunction are unclear. We induced hyper- (HYPER)
and hypothyroidism (HYPO) by daily administration of a 12 mg/l of levothyroxine and 250 mg/l of methimazole in drinking water
of rats, respectively, for 42 days. The white adipose tissues and serum sample were taken on days 15, 28, 42 and also 2 weeks
after treatment cessation. Analysis of adiponectin gene expression was performed by real-time PCR and 2−ΔΔct method. The levels of adipose tissue adiponectin mRNA in the HYPO rats were decreased during the 6-week treatment when compared
to control rats (<0.05) and were increased significantly 2 weeks after HYPO cessation (P < 0.05). This decline in adiponectin gene expression occurred in parallel with a decrease in T3, T4, fT3 and fT4 concentrations
(P < 0.05). In opposite to HYPO rats, adipose adiponectin gene expression was increased in HYPER rats during the 6-week treatment
in parallel with an increase the thyroid hormones concentrations (P < 0.05), and its expression was decreased 2 weeks after HYPER cessation (P < 0.05). Adiponectin gene expression levels showed significant negative correlations with concentrations of LDL (HYPO; r = −0.806, P = 0.001 and HYPER; r = −0.749, P = 0.002), triglyceride (HYPO; r = −0.825, P = 0.001 and HYPER; r = −0.824, P = 0.001) and significant positive correlations with concentrations of glucose (HYPO; r = 0.674, P = 0.004 and HYPER; r = 0.866, P = 0.001) and HDL (HYPO; r = 0.755, P = 0.001 and HYPER; r = 0.839, P = 0.001). The current study provides evidence that adiponectin gene expression in adipose tissue is regulated by thyroid
hormones at the translation level and that lipid and carbohydrate disturbances in a patient with thyroid dysfunction may be,
in part, due to adiponectin gene expression changes. 相似文献
14.
15.
Ischemia–reperfusion (I/R) cannot be avoided in liver transplantation procedures, and apoptosis is a central mechanism of
cell death after liver reperfusion. Protective effect of recombinant erythropoietin (rhEPO) on liver apoptosis has not been
clearly investigated. This work investigated intraportal (IP) rhEPO-protective effect in a rat model of hepatic I/R-induced
apoptosis and its appropriated time and dose of administration. Eight groups were included (n = 10/group): sham-operated, I/R (45 min ischemia and 2 h reperfusion), preconditioned rhEPO I/R (24 h or 30 min before ischemia),
and postconditioned rhEPO I/R (before reperfusion) using two different rhEPO doses (1,000 and 5,000 IU/kg). When compared
with the sham-operated group, the I/R group showed significant increase of serum levels of aspartate and alanine aminotransferases
(AST, ALT), hepatic caspase-9 activity(894.99 ± 176.90 relative fluorescence units (RFU)/mg/min versus 458.48 ± 82.96 RFU/mg/min),
and Fas ligand (FasL) expression, histopathological damages, and significant decrease in the antiapoptotic Bcl-xL/apoptotic
Bax ratio(0.38 ± 0.21 versus 3.35 ± 0.77) rhEPO-improved ALT and AST but failed to reduce FasL expression in all groups compared
with the I/R group. Thirty minutes and 24 h preconditioning with rhEPO (1,000 IU/kg) increased Bcl-xL/Bax ratio and reduced
caspase-9 activity, and the same effect was observed when higher dose was given 24 h before ischemia. Preconditioning was
more effective than postconditioning in improving caspase-9 activity, and no dose-dependent effect was observed. In conclusion,
single IP rhEPO injection 30 min before ischemia has an advantage over rhEPO postconditioning in improving post-hepatic I/R-induced
apoptosis with no additional time- and dose-dependent effects which may provide potentially useful guide in liver transplantation
procedures. 相似文献
16.
Fine grinding of barley grain has traditionally been considered to be a potential risk to rumen function, feed intake and milk yield. These concerns are thought to be reduced by steam-rolling or coarse dry rolling. We hypothesized that finely ground barley grain is as effective in stimulating feed intake and milk production as are dry- and steam-rolled barley grain, and so the objective was to determine effects of feeding either (1) finely ground, (2) steam-rolled, (3) finely dry-rolled, or (4) coarsely dry-rolled barley grain on rumen fermentation, digestibility and milk yield and composition. Eight multiparous midlactation Holstein cows were used in a replicated 4×4 Latin square design experiment with four periods of 21 d. Diets contained 256 g barley grain/kg on a dry matter (DM) basis. Processing method did not affect milk yield and composition, DM intake, rumen pH and volatile fatty acids, fecal and urine pH, and apparent total tract nutrient digestibility. Results suggest that finely ground barley grain is no different than dry-rolled and steam-rolled barley grains in stimulating feed intake and productivity of midlactation cows, when 256 g of dietary DM/kg is barley grain. 相似文献
17.
A pioneering limnological investigation was carried out in Bhutan in a small peat bog in the Trashiyangtse district (1950 m
above sea level) from February 2000 to January 2002. The sampled pond water had low transparency (55.0–95.0 cm), was typically
acidic (pH 5.69–6.58) with soft water (alkalinity, 11.0–36.0 mg/l; total hardness, 10.0–34.0 mg/l), and had low to moderate
specific conductivity (17.0–62.0 μS/cm). Further, moderate Na (2.0–6.8 mg/l), K (1.8–13.5 mg/l), sulphate (0.85–2.99 mg/l),
and silicate (2.5–15.0 mg/l) concentrations as well as low nutrient levels such as phosphate (0.006–0.170 mg/l) and nitrate
(0.003–0.180 mg/l) characterize the water in the peat bog. The recorded net plankton comprised 27 species of phytoplankton
and 49 species of zooplankton, with the latter indicating greater homogeneity and breaking down into Rotifera (23 species)
> Cladocera (13 species) > Rhizopoda (8 species) > Copepoda (3 species) > Ostracoda = Nematoda (1 species each). On the other
hand, the net plankton density ranged between 93 and 692 number/l (n/l) with numerical dominance by phytoplankton (68.5% ±
12%), of which Chlorophyceae were predominant (90 ± 63 n/l). Zooplankton showed moderately high diversity (2.745 ± 0.293)
and evenness (0.925 ± 0.049) and exhibited almost equal abundance of four recorded groups, namely Cladocera (20 ± 15 n/l)
> Rotifera (15 ± 6 n/l) > Copepoda (14 ± 7 n/l) > Rhizopoda (14 ± 4 n/l). While no significant impact of abiotic factors was
recorded on zooplankton density, rainfall alone was the most important factor that influenced net plankton and various groups
of phytoplankton. Comments on some comparative limnological attributes are also made with similar as well as different habitats
in the nearby Himalayan countries. 相似文献
18.
Effects of Selenium with Vitamin E and Melatonin on Cadmium-Induced Oxidative Damage in Rat Liver and Kidneys 总被引:2,自引:0,他引:2
The present study was performed to determine the protective effects of melatonin alone and vitamin E with selenium combination
against cadmium-induced oxidative damage in rat liver. A total of 60 male rats were equally divided into five groups, one
of which acted as control receiving subcutaneous injections of physiological saline. The remaining four groups were treated
with subcutaneous injections of cadmium chloride at a dose of 1 mg/kg weight. The first study group received no treatment.
The second group was treated with a combination of 60 mg/kg vitamin E and 1 mg/kg sodium selenite. Group 3 was treated with
10 mg/kg melatonin, and the four group received a combination of vitamin E, sodium selenite, and melatonin at the doses mentioned
above. After 1 month, the animals were killed, and liver and kidneys were excised for histopathological inspection and determination
of tissue malondialdehyde and the activity of superoxide dismutase. The animals receiving no treatment showed significantly
higher malondialdehyde levels and reduced activity of superoxide dismutase (p < 0.05). Treatment with antioxidants resulted in a significant reduction in malondialdehyde when compared to nontreated animals
(p < 0.05) and increase in the enzyme activity that was almost the same as the controls. The pathological findings were also
in parallel with the results of the biochemical analysis. In conclusion, all the agents tested had protective effects against
cadmium-induced oxidative damage. 相似文献
19.
The aim of the study was to determine the relationship of fluoride in drinking water to liver function in individuals living
in normal and seven endemic fluorosis areas of Punjab, India. The concentration of fluoride in drinking water of different
areas varied from 5.9 to 24.5 mg/L. Study group consisted of 705 patients in the age group between 20 and 60 years (mean age
of 39.35 ± 11.27) affected with osteodental fluorosis were compared with 300 age- and sex-matched controls (with mean age
of 35.28 ± 8.25 years). Biochemical data was analyzed by one-way analysis of variance (ANOVA) with post hoc Tukey–Kramer and
Bonferroni multiple comparison tests. The relationship between hepatic enzymes was calculated by Pearson’s correlation and
linear regression. The results revealed significantly (P < 0.001) higher concentration of serum fluoride in patients when compared to control. The mean activities of cyclic adenosine
monophosphate (AMP), alkaline phosphatase (ALKP), acid phosphatase (ACP), aspartate aminotransaminase (AST), and alanine aminotransaminase
(ALT) were significantly (P < 0.05–0.001) elevated in patients from all fluoride areas. ANOVA with post hoc Turkey–Kramer and Bonferroni multiple comparison
test demonstrated a significant (P < 0.0001) variance in the activities of cAMP, ALKP, ACP, AST, and ALT in fluorotic patients, with elevation in water fluoride
levels. Maximum elevation of 196.14% (ACP), 99.31% (cyclic adenosine monophosphate; cAMP), 72.08% (ALT), 60.14% (AST), and
least 21.35% (ALKP) was recorded in patients exposed to 24.5 mg/L fluoride in drinking water. There was positive correlation
between water fluoride, serum fluoride and AST (r = 0.77, 0.91), ALT (r = 0.82, 0.90), ALKP (r = 0.88, 0.97), and ACP (r = 0.74, 0.85). Pearson’s correlation demonstrated highly significant (P < 0.05) positive relationship between water fluoride and cAMP (regression equation: Y = 0.9807 ×+ 22.081 Y = 0.9807 \times + 22.081 , = 0.84; r = 0.92, P < 0.05). The increased levels of transaminases in fluorotic patients suggest alteration in liver functions. The level of
alkaline and acid phosphatase was increased during fluoride intoxication which is also an early marker of hepatic cell damage
because of its specificity and catalytic activity. The elevated levels of enzymes are reflective of bone disorders, which
are characterized by increased osteoblastic activity. There levels increased several times if cellular damage occurs in the
liver. The results suggest that fluoride exposure intensifies the activities of hepatic function enzymes in osteofluorosis. 相似文献
20.
The biodegradation of phenol by a pure culture of Pseudomonas putida was investigated in a continuously fed stirred-tank reactor, under aerobic conditions. The dilution rate was varied between
0.0174 h−1 and 0.278 h−1, covering a wide range of dissolved oxygen and the inhibition region of phenol. Through non-linear analysis of the data,
a dual-substrate growth kinetics, Haldane kinetics for phenol and Monod kinetics for oxygen, was derived with high correlation
coefficients. Respective biokinetic parameters were evaluated as μm = 0.569 h−1, K
p = 18.539 mg/l, K
i = 99.374 mg/l, K
o = 0.048 mg/l, Y
x/p = 0.521 g microorganism/g phenol and Y
x/o = 0.338 g microorganism/g oxygen, being in good agreement with other studies in the literature. Maintenance factors for both
phenol and oxygen were calculated for the first time for P. putida while the saturation coefficient for oxygen, K
o, was genuinely evaluated from the constructed model, not imported or adapted from other studies as reported in the literature.
All pertinent biokinetic parameters for P. putida have been calculated from continuous system data, which are most appropriate for use in continuous bioprocess applications.
Received: 29 July 1996 / Received revision: 18 November 1996 / Accepted: 23 November 1996 相似文献