Toxicity of silver nanoparticles on the brain of Oreochromis niloticus and Tilapia zillii

BackgroundSilver nanoparticles (Ag-NPs) are widely used nowadays in a variety of commercial applications including medical, health care, textiles and household supplies.ObjectivesThe current study was designed to determine the median lethal dose (LC₅₀) of Ag-NPs on Oreochromis niloticus and Tilapia zillii.MethodsAcute and sub-acute toxicity study of the Ag-NPs on brain tissues was carried out using different concentrations of the NPs at 2 mg L and 4 mg L. These concentrations were dispersed in deionized water with the exception of the control groups in the experiments. Biochemical and molecular analysis were conducted on tissue homogenates in order to evaluate the potential effects of NPs on the antioxidant system.ResultsThe Ag-NP acute toxicity (96 h LC₅₀) values of 19.5 ± 2 and 20 ± 2.4 mg/L were reported for O. niloticus and T. zillii respectively. Fish exposed to 2 mg/L Ag-NPs did not show any significant change in the levels of reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity or genes expression and malondialdehyde (MDA) level. In contrary, a dose of 4 mg/L showed a significant reduction in the levels all the above-mentioned parameters except in MDA level where it was significantly induced.ConclusionResults indicate that exposure of O. niloticus and T. zillii to Ag-NPs (4 mg/L) has deleterious effects on brain antioxidant system, whereas a dose of 2 mg/L has no effects.     

Protective effects of the apigenin-O/C-diglucoside saponarin from Gypsophila trichotoma on carbone tetrachloride-induced hepatotoxicity in vitro/in vivo in rats

This study investigated the hepatoprotective activity of saponarin, isolated from Gypsophila trichotoma Wend., using in vitro/in vivo hepatotoxicity model based on carbone tetrachloride (CCl₄)-induced liver damage in male Wistar rats. The effect of saponarin was compared with those of silymarin. In vitro experiments were carried out in primary isolated rat hepatocytes. Cell incubation with CCl₄ (86 μmol l⁻¹) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH and elevation in MDA quantity. Cell pre-incubation with saponarin (60–0.006 μg/ml) significantly ameliorated CCl₄-induced hepatic damage in a concentration-dependent manner. These results were supported by the following in vivo study. Along with decreased MDA quantity and increased level of cell protector GSH, seven day pre-treatment of rats with saponarin (80 mg/kg bw; p.o.) also prevented CCl₄ (10%, p.o.)-caused oxidative damage by increasing antioxidant enzyme activities (CAT, SOD, GST, GPx, GR). Biotransformation phase I enzymes were also assessed. Administered alone, saponarin decreased EMND and AH activities but not at the same extent as CCl₄ did. However, pre-treatment with saponarin significantly increased enzyme activities in comparison to CCl₄ only group. The observed biochemical changes were consistent with histopathological observations where the hepatoprotective effect of saponarin was comparative to the effects of the known hepatoprotecor silymarin. Our results suggest that saponarin, isolated from Gypsophila trichotoma Wend., showed in vitro and in vivo hepatoprotective and antioxidant activity against CCl₄-induced liver damage.     

The effect of age and gender on 38 chemical element contents in human iliac crest investigated by instrumental neutron activation analysis

ProjectTo understand the role of major, minor, and trace elements in the etiology of bone diseases including osteoporosis, it is necessary to determine the normal levels and age-related changes of bone chemical elements.ProcedureThe effect of age and gender on 38 chemical element contents in intact iliac crest of 84 apparently healthy 15–55 years old women (n=38) and men (n=46) was investigated by neutron activation analysis.ResultsMean values (M±SEM) for mass fraction (on dry weight basis) of Ca, Cl, Co, Fe, K, Mg, Mn, Na, P, Rb, Sr, and Zn for both female and male taken together were Ca – 169±3 g/kg, Cl – 1490±43 mg/kg, Co – 0.0073±0.0024 mg/kg, Fe – 177±24 mg/kg, K – 1820±79 mg/kg, Mg – 1840±48 mg/kg, Mn – 0.316±0.013 mg/kg, Na – 4970±87 mg/kg, P – 79.7±1.5 g/kg, Rb – 1.89±0.22 mg/kg, Sr – 312±15 mg/kg, and Zn – 65.9±3.4 mg/kg, respectively. The upper limit of mean contents of Cs, Eu, Hg, Sb, Sc, and Se were Cs≤0.09 mg/kg, Eu≤0.005 mg/kg, Hg≤0.005 mg/kg, Sb≤0.004 mg/kg, Sc≤0.001 mg/kg, and Se≤0.1 mg/kg, respectively. In all bone samples the contents of Ag, As, Au, Ba, Br, Cd, Ce, Cr, Gd, Hf, La, Lu, Nd, Sm, Ta, Tb, Th, U, Yb, and Zr were under detection limits.ConclusionsThe Ca, Mg, and P contents decrease with age, regardless of gender. Higher Ca, Mg, P, and Sr mass fractions as well as lower Fe content are typical of female iliac crest as compared to those in male bone.     

Effect of Zinc nanoparticles on oxidative stress-related genes and antioxidant enzymes activity in the brain of Oreochromis niloticus and Tilapia zillii

This study was carried out to determine the median lethal concentrations (LC₅₀) of Zinc nanoparticles (ZnNPs) on Oreochromis niloticus and Tilapia zillii. The biochemical and molecular potential effects of ZnNPs (500 and 2000 μg L⁻¹) on the antioxidant system in the brain tissue of O. niloticus and T. zillii were investigated. Four hundred fish were used for acute and sub-acute studies. ZnNP LC₅₀ concentrations were investigated in O. niloticus and T. zillii. The effect of 500 and 2000 μg L⁻¹ ZnNPs on brain antioxidants of O. niloticus and T. zillii was investigated. The result indicated that 69 h LC₅₀ was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. Fish exposed to 500 μg L⁻¹ ZnNPs showed a significant increase in reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity and gene expression. On the contrary, malondialdehyde (MDA) levels significantly decreased. Meanwhile, fish exposed to 2000 μg L⁻¹ ZnNPs showed a significant decrease of GSH, tGSH levels, SOD, CAT, GR, GPx and GST activity and gene expression. On the contrary, MDA levels significantly increased. It was concluded that, the 96 h LC₅₀ of ZnNPs was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. ZnNPs in exposure concentrations of 2000 μg/L induced a deleterious effect on the brain antioxidant system of O. nilotica and T. zillii. In contrast, ZnNPs in exposure concentrations of 500 μg L⁻¹ produced an inductive effect on the brain antioxidant system of O. nilotica and T. zillii.     

Improvement in Pancreatic β-Cell Function with Vitamin D and Calcium Supplementation in Vitamin D-Deficient Nondiabetic Subjects

ObjectiveThere are varied reports on the effect of vitamin D supplementation on β-cell function and plasma glucose levels. The objective of this study was to examine the effect of vitamin D and calcium supplementation on β-cell function and plasma glucose levels in subjects with vitamin D deficiency.MethodsNondiabetic subjects (N = 48) were screened for their serum 25-hydroxyvitamin D (25-OHD), albumin, creatinine, calcium, phosphorus, alkaline phosphatase, and intact parathyroid hormone (PTH) status. Subjects with 25-OHD deficiency underwent a 2-hour oral glucose tolerance test. Cholecalciferol (9,570 international units [IU]/day; tolerable upper intake level, 10,000 IU/day; according to the Endocrine Society guidelines for vitamin D supplementation) and calcium (1 g/day) were supplemented.ResultsThirty-seven patients with 25-OHD deficiency participated in the study. The baseline and postvitamin D/calcium supplementation and the difference (corrected) were: serum calcium, 9 ± 0.33 and 8.33 ± 1.09 mg/dL (− 0.66 ± 1.11 mg/dL); 25-OHD, 8.75 ± 4.75 and 36.83 ± 18.68 ng/mL (28.00 ± 18.33 ng/mL); PTH, 57.9 ± 29.3 and 36.33 ± 22.48 pg/mL (− 20.25 ± 22.45 pg/mL); fasting plasma glucose, 78.23 ± 7.60 and 73.47 ± 9.82 mg/dL (− 4.88 ± 10.65 mg/dL); and homeostasis model assessment-2–percent β-cell function C-peptide secretion (HOMA-2–%B C-PEP), 183.17 ± 88.74 and 194.67 ± 54.71 (11.38 ± 94.27). Significant differences were observed between baseline and post-vitamin D/calcium supplementation serum levels of corrected calcium (Z, − 3.751; P < .0001), 25-OHD (Z, − 4.9; P < .0001), intact PTH (Z, − 4.04; P < .0001), fasting plasma glucose (Z, − 2.7; P < .007), and HOMA-2–%B C-PEP (Z, − 1.923; P < .05) as determined by Wilcoxon signed rank test. Insulin resistance as measured by HOMA was unchanged.ConclusionOptimizing serum 25-OHD concentrations and supplementation with calcium improves fasting plasma glucose levels and β-cell secretory reserve. Larger randomized control studies are needed to determine if correction of 25-OHD deficiency will improve insulin secretion and prevent abnormalities of glucose homeostasis. (Endocr Pract. 2014;20:129-138)     

Hepatoprotective and antioxidant activity of N-Trisaccharide in different experimental rats

ObjectivesTo investigate the hepatoprotective, antioxidant and antihyperlipidemic effect of N-Trisaccharide isolated from Cucumis prophetarum (L.) on different experimental rats.MethodsN-Trisaccharide (25 and 50 mg/kg.b.w), silymarin (25 mg/kg) and glibenclamide (25 mg/kg) was orally administered once daily for 28 days and toxicity evaluation studies were carried out. Liver damage was assessed by determining DNA damage, serum enzyme activities and hepatic histopathology of carbon tetrachloride (CCl₄) induced hepatic injury in rats. Enzymatic and non enzymatic antioxidant levels in liver and kidney were determined and biochemical parameters such as, serum lipid profile, renal function markers were estimated in type 2 diabetic rats.ResultsDNA fragmentation analysis revealed the protective effect of N-Trisaccharide on liver DNA damage. Histopathological studies indicated that CCl₄-induced liver injury was less severe in N-Trisaccharide (25 and 50 mg/kg) treated group. Given at the above doses conferred significant protection against the hepatotoxic actions of CCl₄ in rats, reducing serum markers like SGOT, SGPT, ALP, creatinine and urea levels back to near normal (p < 0.05) compared to untreated rats. In diabetic rats, N-Trisaccharide treatment significantly reversed abnormal status of enzymatic and non-enzymatic antioxidants levels to near normal. Also, serum lipids such as TG, TC, LDL-C and VLDL-C levels were significantly (p < 0.05) reduced compared to diabetic untreated rats.ConclusionPresent study results confirm that N-Trisaccharide possesses significant antihyperlipidemic, antioxidant and hepatoprotective properties.     

Increased Atherogenic Low-Density Lipoprotein Cholesterol in Untreated Subclinical Hypothyroidism

ObjectiveTo evaluate the effects of physiologic doses of levothyroxine replacement on the lipoprotein profile in patients with subclinical hypothyroidism (SCH).MethodsIn a prospective, double-blind, placebo- controlled study, we enrolled 120 patients—mostly, but not exclusively, premenopausal women—with SCH. Patients were randomly assigned to either a levothyroxine- treated group (n = 60) or a placebo (control) group (n = 60). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) were measured before and 52 weeks after assignment to either group.ResultsIn the levothyroxine-treated group, the lipoprotein mean values before and after the 52-week study were as follows: TC, 5.05 ± 0.98 mmol/L versus 4.74 ± 0.87 mmol/L (P < .0001); LDL-C, 3.30 ± 0.90 mmol/L versus 2.89 ± 0.59 mmol/L (P < .01); TG, 1.18 ± 0.71 mmol/L versus 0.95 ± 0.53 mmol/L (P < .002); and HDL-C, 1.20 ± 0.33 mmol/L versus 1.19 ± 0.32 mmol/L (P = .29). In the control group, TC, HDL-C, and TG values remained unchanged after 52 weeks in comparison with baseline, but LDL-C mean values increased from 2.79 ± 0.60 mmol/L to 3.11 ± 0.77 mmol/L, a change that was statistically significant (P < .001). At the end of the study, the lipid profile changes between levothyroxine- treated and control groups were compared. Total cholesterol and LDL-C were significantly lower in the levothyroxine-receiving group (P < .029 and P < .0001, respectively) in comparison with the control group. The difference did not reach statistical significance for TG and HDL-C values.ConclusionIn premenopausal women, SCH has a negative effect on the lipoprotein profile and may translate into a sizable cardiovascular risk if left untreated. (Endocr Pract. 2008;14:570-575)     

HDL-associated dehydroepiandrosterone fatty acyl esters: Enhancement of vasodilatory effect of HDL

ObjectiveDehydroepiandrosterone (DHEA) and high-density lipoprotein (HDL) are both vascular relaxants. In the circulation, HDL transports DHEA fatty acyl esters (DHEA-FAEs), which are naturally occurring lipophilic derivatives of DHEA. We studied in isolated rat mesenteric arteries whether HDL-associated DHEA-FAE improves the vasodilatory effect of HDL.Methods and resultsTo prepare DHEA-FAE-enriched HDL, we incubated DHEA with human plasma. After incubation, HDL was isolated, purified, and added in cumulative doses (0.1–125 μg/ml) to noradrenaline-precontracted rat arterial rings. DHEA-FAE-enriched HDL caused a dose-dependent relaxation (maximal 43 ± 4%), which was significantly stronger than the effect of HDL from the control incubation without addition of DHEA (25 ± 2%, p < 0.001). When plasma incubation of DHEA was carried out in the presence of lecithin:cholesterol acyltransferase (LCAT) inhibitor, the relaxation response to HDL (25 ± 3%) did not differ from the control HDL (p = 0.98). Pretreatment of the arterial rings with nitric oxide synthase (NOS) antagonist impaired the relaxation response to DHEA-FAE-enriched HDL (43 ± 4% vs. 30 ± 3%, p = 0.008). Similar experiments were performed with 17β-estradiol (E₂). Compared to control HDL, E₂-FAE-enriched HDL induced slightly but non-significantly stronger relaxation.ConclusionsDHEA-FAE-enriched HDL was a stronger vasodilator than native HDL, and vascular relaxation was in part mediated by NOS, suggesting that DHEA-FAE may improve HDL's antiatherogenic function.     

Assay of Free Thyroxine and Free Triiodothyronine in Fine-Needle Aspiration of Thyroid Nodules: a Useful and Low-Cost Assessment

ObjectiveTo evaluate whether analysis of thyroid hormones in fine-needle aspiration (FNA) of thyroid nodules can provide information about the functional status and the nature of the nodules.MethodsWe studied 4 groups of patients: group 1, 17 patients with autonomous hyperfunctioning thyroid nodules; group 2, 52 patients with cold nonfunctioning thyroid nodules; group 3, 12 patients with malignant thyroid nodules; and group 4 (control group), 10 patients with nonthyroid nodular lesions (enlarged parathyroid glands or lymph nodes). The assay of thyroid hormones was performed in FNA after the washing of needles and, with patient consent, also in normal thyroid parenchyma.ResultsThe free thyroxine (FT₄) and free triiodothyronine (FT₃) values were remarkably high in group 1 (mean, 5.5 ± 0.53 ng/dL and 27.6 ± 3.1 pg/mL, respectively; P < 0.05 versus group 2 and group 4, the control group). The levels of FT₄ and FT₃ were very low in group 3 (< 0.2 ng/dL and < 1.0 pg/mL, respectively; P < 0.05 versus group 2). Thyroglobulin values in FNA specimens were much higher than the normal range in human serum, but no significant differences were found between the various groups. The control group had low levels of FT₄ and FT₃ (< 0.2 ng/dL and < 1.0 pg/mL, respectively) in conjunction with low levels of thyroglobulin, whereas parathyroid hormone levels were high in parathyroid nodules.ConclusionThese results show that assay of FT₄ and FT₃ in FNA can yield information about the functional status of thyroid nodules and, indirectly, about the nature of nodules. In this era of sophisticated new molecular markers in FNA cytology, this low-cost diagnostic method can be readily performed in every laboratory. (Endocr Pract. 2004;10:311-316)     

Research on antioxidant effects and estrogenic effect of formononetin from Trifolium pratense (red clover)

Antioxidant and estrogenic effects of formononetin on ovariectomized mice have been investigated in the present study. The adult female Kunming mice were divided into 5 groups: sham-operated group, ovariectomized group, stilbestrol replacement therapy group (0.20 mg/kg day), low-dose formononetin group (0.05 g/kg day) and high-dose formononetin group (0.5 g/kg day). The mice in the latter 4 groups were ovariectomized. The drug was given by oral administration for 6 months. Estrogenic effect was determined by the change of uterine weight, and oxidant effects were determined by the content of SOD, GSH-Px, CAT and MDA. The intake of formononetin increased the uterine weight of the mice significantly as well as the content of SOD, GSH-Px, CAT, and reduced MDA in body. Formononetin had obvious antioxidant effects and estrogenic effect, and the estrogenic effect was not dosage-related.     

Antioxidant activity and protection of human umbilical vein endothelial cells from hydrogen peroxide-induced injury by DMC,a chalcone from buds of Cleistocalyx operculatus

The aim of this work was to study the antioxidant activity and the protective effect of 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (DMC), the main compound from the buds of Cleistocalyx operculatus, on human umbilical vein endothelial cells against cytotoxicity induced by H₂O₂. The antioxidant activities of DMC were measured by ABTS assay, ferric reducing antioxidant power (FRAP) and hydroxyl radical scavenging activity, and protective effects of DMC on human umbilical vein endothelial cells against cytotoxicity induced by H₂O₂ were tested. DMC was found to have high ABTS radical scavenging activity (176.5 ± 5.2 μmol trolox equivalents/500 μmol DMC) and strong ferric reducing antioxidant power (213.3 ± 5.8 μmol trolox equivalents/500 μmol DMC). In addition, DMC scavenged the hydroxyl radicals, with IC₅₀ values of 243.7 ± 6.3 μM, slightly lower than the reference antioxidant ascorbic acid (ASC). Moreover, DMC could protect the human umbilical vein endothelial cells against H₂O₂-induced cytotoxicity by decrease intracellular and extracellular ROS levels, reduction in catalase (CAT) activity and increment in malondialdehyde (MDA) level. These results suggested that DMC has the potential to be used in the therapy of oxidative damage.     

Synergistic hepatotoxicity of N,N-dimethylformamide with carbon tetrachloride in association with endoplasmic reticulum stress

N,N-Dimethylformamide (DMF) is an organic solvent extensively used in industries such as synthetic leather, fibers and films, and induces liver toxicity and carcinogenesis. Despite a series of experimental and clinical reports on DMF-induced liver failure, the mechanism of toxicity is yet unclear. This study investigated whether DMF in combination with a low dose of hepatotoxicant enhances hepatotoxicity, and if so, on what mechanistic basis. Treatment of rats with either DMF (50–500 mg/kg/day, for 3 days) or a single low dose of CCl₄ (0.2 ml/kg) alone caused small increases in plasma transaminases and lactate dehydrogenase activities. However, combinatorial treatment of DMF with CCl₄ markedly increased blood biochemical changes. Histopathology confirmed the synergism in hepatotoxicity. Moreover, DMF + CCl₄ caused PARP cleavage and caspase-3 activation, but decreased the level of Bcl-xL, all of which confirmed apoptosis of hepatocytes. Consistently, DMF + CCl₄ treatment markedly increased lipid peroxidation. By contrast, treatment of DMF in combination with lipopolysaccharide, acetaminophen or d-galactosamine caused no enhanced hepatotoxicity. Given the link between endoplasmic reticulum (ER) dysfunction and cell death, ER stress response was monitored after DMF and/or CCl₄ treatment. Whereas either DMF or CCl₄ treatment alone marginally changed the expression levels of glucose-regulated protein 78 and 94 and phosphorylated PKR-like ER-localized eIF2α kinase, concomitant treatment with DMF and CCl₄ synergistically induced them with increases in glucose-regulated protein 78 and C/EBP homologous protein mRNAs. Our results demonstrate that DMF treatment in combination with CCl₄ synergistically increases hepatocyte death, which may be associated with the induction of severe ER stress.     

Lowering of oxidative stress improves endothelial function in healthy subjects with habitually low intake of fruit and vegetables: A randomized controlled trial of antioxidant- and polyphenol-rich blackcurrant juice

Inadequate intake of the recommended five-a-day fruit and vegetable portions might contribute to increased cardiovascular disease risk. We assessed the effects of dietary intake of a blackcurrant juice drink, rich in vitamin C and polyphenols, on oxidative stress and vascular function. This was a double-blind, placebo-controlled, parallel group study of 66 healthy adults who habitually consume <2 portions of fruit and vegetables per day. Participants were randomly allocated to consume 250 ml of placebo (flavored water) or low or high blackcurrant juice drink four times a day for 6 weeks. Flow-mediated dilation (FMD) and plasma concentrations of F₂-isoprostanes and vitamin C were measured. In the high blackcurrant juice drink group FMD increased significantly (5.8±3.1 to 6.9±3.1%, P=0.022) compared with the placebo group (6.0±2.2 to 5.1±2.4%). Plasma vitamin C concentration increased significantly in the low (38.6±17.6 to 49.4±21.0 µmol/L, P<0.001) and high (34.6±20.4 to 73.8±23.3 µmol/L, P<0.001) blackcurrant juice drink groups compared with the placebo group (38.1±21.0 to 29.0±17.6 µmol/L). F₂-isoprostane concentrations were significantly lower in the high blackcurrant juice drink group (225±64 pg/ml) compared with the low blackcurrant juice drink (257±69 pg/ml, P=0.002) and placebo group (254±59 pg/ml, P=0.003). At follow-up, changes in plasma vitamin C correlated significantly with changes in FMD (r=0.308, P=0.044). Consumption of blackcurrant juice drink high in vitamin C and polyphenols can decrease oxidative stress and improve vascular health in individuals with habitually low dietary fruit and vegetable intake.     

Copper/zinc and copper/selenium ratios,and oxidative stress as biochemical markers in recurrent aphthous stomatitis

ProjectRecurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae, and oxidative stress presumably contributes to its pathogenesis. The aim of this study is to scrutinize the relationship between oxidative stress and serum trace elements (copper, Cu; zinc, Zn; selenium, Se), and to evaluate the ratios of Cu/Zn and Cu/Se in this disorder.ProcedurePatients with RAS (n = 33) and age- and sex-matched healthy control subjects (n = 30) were enrolled in this study. Malondialdehyde (MDA) concentrations in plasma and the activities of superoxide dismutase (SOD1; CuZnSOD), glutathione peroxidase (GPx) and catalase (CAT) in erythrocyte were determined as spectrophotometric. Also, the levels of Se, Zn and Cu in serum were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction.Results and conclusionsOxidative stress was confirmed by the significant elevation in plasma MDA, and by the significant decrease in CAT, SOD1, and GPx (p < 0.05). When compared to controls, Zn and Se levels were significantly lower in patients, whereas Cu levels was higher in RAS patients than those in controls (p < 0.05). In addition, the correlation results of this study were firstly shown that there were significant and positive correlations between Se–CAT, Se–GPx, and Cu–MDA parameters, but negative correlations between Se–Cu, Se–MDA, Cu–CAT, Cu–SOD1 and Cu–GPx parameters in RAS patients. Furthermore, the ratios of Cu/Zn and Cu/Se were significantly higher in the patients than the control subjects (p < 0.05). Our results indicated that lipid peroxidation associated with the imbalance of the trace elements seems to play a crucial role in the pathogenesis of RAS. Furthermore, the serum Cu/Zn and Cu/Se ratios may be used as biochemical markers in these patients.     

Effects of intermittent watering on water balance and feed intake in male Ethiopian Somali goats

The objective of this study was to investigate the regulation of water balance and dry matter (DM) intake of male Ethiopian Somali goats. Twenty-eight goats were grouped into four treatments; goats watered every day (W1), every 2nd day (W2), every 3rd day (W3) and every 4th day (W4) for a total period of 72 days. Plasma sodium and potassium were analyzed by flame photometry, plasma osmolality by freezing point depression, plasma protein concentration by TS refractometry, and the plasma vasopressin concentration by radioimmunoassay. Goats were fed grass hay ad libitum and were given 200 g of concentrates daily. The calculated daily water intake (ml/kg BW^0.75) of W1, W2, W3 and W4 was 128 ± 4, 86 ± 4, 88 ± 4 and 78 ± 4, respectively, (P < 0.001, W1 versus the other groups). Calculated total concentrates intake did not change, whereas Group W2 and W4 consumed less hay on days of water deprivation (W1 versus W2, P < 0.01; W1 versus W4, P < 0.001). Plasma sodium concentration of W1 was 143 ± 1 mmol/l. Intermittent watering increased plasma sodium concentration from 140 or 141 ± 1 mmol/l to 145 or 146 ± 1 mmol/l every 2nd day in group W2. In W3, it increased from 139 ± 1 to 146 ± 1 mmol/l and in W4 from 137 ± 1 to 149 ± 1 mmol/l (P < 0.001 for all) on days after watering compared to last day of water deprivation, respectively. Corresponding changes were observed in plasma osmolality. Total plasma protein concentration increased only in W3 from 65 ± 1 to 67 ± 1 mmol/l on day 3 (P < 0.01) and in W4 from 65 ± 1 to 67 and 68 ± 1 mmol/l on days 3 and 4, respectively (P < 0.05). The plasma vasopressin concentration of W1 was close to 0.80 ± 0.28 pmol/l on all days, but it increased on dehydration days in W2 (P < 0.05). In W3, the vasopressin concentration increased from 0.95 or 1.19 pmol/l the day after watering to 3.11 ± 0.28 pmol/l on day 3 (P < 0.01). In W4, it was 0.82 ± 0.31 pmol/l the day after watering and reached 6.06 ± 0.31 pmol/l on day 4 (P < 0.001). We conclude that male Ethiopian Somali goats can be watered once every 3rd days, and that longer interval is not recommended because it demands marked mobilization of water saving mechanisms and causes decreased DM intake.     

Influences of short-term pre-slaughter dietary manipulation in sheep and goats on pH and microbial loads of gastrointestinal tract

Sheep (BW = 39.9 kg, n = 16) and goats (BW = 32.8 kg, n = 16) were used in a completely randomized design to determine the effect of short-term pre-slaughter diet and feed deprivation (FD) time on pH and microbial loads in the gastrointestinal tract (GIT) contents. In a 2 × 2 × 2 factorial treatment arrangement, the main effects of species, diet, and FD time prior to slaughter and their interactions were studied. Animals were fed either a hay or concentrate diet for 4 d and then feed deprived for either 12 or 24-h prior to slaughter. The pH of rumen and colon contents as well as weight of GIT was measured. The contents of rumen and rectum were also sampled for microbial analysis. The GIT of sheep (1.82 kg) was heavier (P < 0.05) than that of goats (1.46 kg). The 12-h FD group (1.74 kg) had a higher (P < 0.05) GIT weight than the 24-h FD group (1.53 kg). Hay-fed animals had higher (P < 0.05) rumen (7.08 vs. 6.43) and colon pH values (7.02 vs. 6.56) than those of the concentrate-fed animals. The 24-h FD group (3.39 ± 0.272 log₁₀CFU/g) contained more (P < 0.05) Escherichia coli in the rumen than did the 12-h FD (2.17 ± 0.272 log₁₀CFU/g) group. The concentrate-fed animals (3.49 ± 0.289 log₁₀CFU/g) had higher (P < 0.05) coliform counts in the rumen than the hay-fed animals (2.43 ± 0.289 log₁₀CFU/g). The 24-h FD group (3.42 ± 0.289 log₁₀CFU/g) had a higher (P < 0.05) concentration of coliform than did the 12-h FD group (2.50 ± 0.289 log₁₀CFU/g). The 24-h FD group (3.31 ± 0.259 log₁₀CFU/g) also had higher (P < 0.05) Enterobacteriaceae counts in the rumen than did in the 12-h FD group (2.47 ± 0.259 log₁₀CFU/g). Goats (5.71 ± 0.158 log₁₀CFU/g) had lower (P < 0.05) total plate counts in the rumen compared to sheep (6.27 ± 0.158 log₁₀CFU/g). The concentrate-fed animals had higher (P < 0.05) E. coli (6.44 vs. 4.01 ± 0.468 log₁₀CFU/g), total coliform (6.74 vs. 4.16 ± 0.469 log₁₀CFU/g), Enterobacteriaceae (6.93 vs. 3.83 ± 0.651 log₁₀CFU/g), and total plate counts (7.79 vs. 7.28 ± 0.170 log₁₀CFU/g) in the rectum than the hay-fed animals. The results indicate that microbial loads in the GIT of small ruminants may be reduced by either feeding hay for 4 d or depriving feed for 12-h prior to slaughter.     

Effects of dietary nitrate supplementation on the oxygen cost of exercise and walking performance in individuals with type 2 diabetes: a randomized,double-blind,placebo-controlled crossover trial

Dietary nitrate supplementation has been shown to reduce the oxygen (O₂) cost of exercise and enhance exercise tolerance in healthy individuals. This study assessed whether similar effects could be observed in individuals with type 2 diabetes (T2DM). In a randomized, double-blind, placebo-controlled crossover study, 48 participants with T2DM supplemented their diet for 4 days with either nitrate-rich beetroot juice (70 ml/day, 6.43 mmol nitrate/day) or nitrate-depleted beetroot juice as placebo (70 ml/day, 0.07 mmol nitrate/day). After each intervention period, resting plasma nitrate and nitrite concentrations were measured subsequent to participants completing moderate-paced walking. Pulmonary gas exchange was measured to assess the O₂ cost of walking. After a rest period, participants performed the 6-min walk test (6MWT). Relative to placebo, beetroot juice resulted in a significant increase in plasma nitrate (placebo, 57±66 vs beetroot, 319±110 µM; P < 0.001) and plasma nitrite concentration (placebo, 680±256 vs beetroot, 1065±607 nM; P < 0.001). There were no differences between placebo juice and beetroot juice for the O₂ cost of walking (946±221 vs 939±223 ml/min, respectively; P = 0.59) and distance covered in the 6MWT (550±83 vs 554±90 m, respectively; P = 0.17). Nitrate supplementation did not affect the O₂ cost of moderate-paced walking or improve performance in the 6MWT. These findings indicate that dietary nitrate supplementation does not modulate the response to exercise in individuals with T2DM.     

Effect of pain location on spatial reorganisation of muscle activity

IntroductionWe aimed to determine whether the changes in muscle activity (in terms of both gross electromyography (EMG) and motor unit (MU) discharge characteristics) observed during pain are spatially organized with respect to pain location within a muscle which is the main contributor of the task.MethodsSurface and fine-wire EMG was recorded during matched low-force isometric plantarflexion from soleus (from four quadrants with fine-wire EMG and from the medial/lateral sides with surface EMG), both gastrocnemii heads, peroneus longus, and tibialis anterior. Four conditions were tested: two control conditions that each preceded contractions with pain induced in either the lateral (Pain_L) or medial (Pain_M) side of soleus.ResultsNeither the presence (p = 0.28) nor location (p = 0.19) of pain significantly altered gross muscle activity of any location (lateral/medial side of soleus, gastrocnemii, peroneus longus and tibialis anterior). Group data from 196 MUs show redistribution of MU activity throughout the four quadrants of soleus, irrespective of pain location. The significant decrease of MU discharge rate during pain (p < 0.0001; Pain_L: 7.3 ± 0.9–6.9 ± 1.1 Hz, Pain_M: 7.0 ± 1.1 to 6.6 ± 1.1 Hz) was similar for all quadrants of the soleus (p = 0.43), regardless of the pain location (p = 0.98). There was large inter-participant variation in respect to the characteristics of the altered MU discharge with pain.ConclusionResults from both surface and fine-wire EMG recordings do not support the hypothesis that muscle activity is reorganized in a simple systematic manner with respect to pain location.     

Marcadores bioquímicos,nutricionales y actividad antioxidante en el síndrome metabólico

Background and objectives1) Nutritional assessment of the diet followed by patients with metabolic syndrome, and 2) biochemical analysis of the oxidation-reduction level in patients with metabolic syndrome.Material and methodsA cross-sectional study was conducted in patients with metabolic syndrome in Murcia. Fifty-three patients, 33 with and 20 without (control group) metabolic syndrome, were selected. The intervention consisted of completion of a recall survey and a test to nutritionally assess dietary intake. Anthropometric and laboratory variables, including those related to antioxidant activity, were also tested.ResultsAntioxidant activity was within normal limits in both groups (1.7 ± 0.2 mmol/L in the control group and 1.8 ± 0.1 mmol/L in the metabolic syndrome group) (NS). Superoxide dismutase levels were not significantly different between the groups. Mean glutathione reductase levels (U/L) were higher in the control group as compared to patients with metabolic syndrome (P < .05). As regards oxidative stress biomarkers, mean isoprostane levels were higher in the control group (4.9 ± 6.2 ng/mL) than in metabolic syndrome patients (3.5 ± 3.9 ng/mL) (P < .05). Oxidized LDL values tended to be higher in metabolic syndrome patients (96 ± 23.2 U/L) as compared to the control group (86.2 ± 17.3  U/L), but differences were not significant.ConclusionsThere is a trend to a poorer nutritional and biochemical profile in patients with metabolic syndrome, who also tend to have a greater degree of oxidative stress.