Interaction of zearalenone and soybean isoflavone in diets on the growth performance, organ development and serum parameters in prepubertal gilts.

The aim of the present research was to determine the interactive effect of zearalenone (ZEA) and soybean isoflavone (ISO) on the growth performance, development of organs and serum parameters in prepubertal gilts. Ninety 75-day-old female pigs (Duroc × Landrace × Yorkshire, 26.5 ± 0.60 kg) were randomly allocated to nine diet treatments during the 21-day study. The experiment employed a 3 × 3 factorial design using a non-soybean meal diet with the addition of 0, 0.5 or 2.0 mg/kg ZEA and 0, 300 or 600 mg/kg ISO. The results indicated that simultaneous addition of ZEA and ISO had no significant influence on the growth performance in prepubertal gilts. Zearalenone with 2 mg/kg increased (p < 0.05) the relative weight of the reproductive organs (including uterus and vagina) but had no obvious effects (p > 0.05) on the relative weight of the heart, liver, lung, kidney and spleen. Isoflavone at 600 mg/kg could offset the increased weight of the reproductive organs induced by ZEA. Simultaneous addition of ZEA and ISO to prepubertal gilts increased the level of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase in the serum (p < 0.05) at day 14 but their levels decreased (p < 0.05) over time. Zearalenone increased the level of malondialdehyde and decreased the concentrations of superoxide dismutase and glutathione peroxidase (p < 0.05) in the serum. The results suggested that ISO added to diets at 600 mg/kg could reduce the increase in the relative weight of reproductive organs and relieve the oxidative stress induced by ZEA added at 2 mg/kg during the growth phase in prepubertal gilts.

Biodetoxification of aflatoxin B1 in cottonseed meal by fermentation of Cellulosimicrobium funkei in duckling diet.

Two experiments were conducted to optimize the fermentation of cottonseed meal by Cellulosimicrobium funkei (C. funkei) for the ability of the bacteria to degrade aflatoxin B1 (AFB1) and then to evaluate the bacterial detoxification in ducklings. In experiment 1, the fermentation of cottonseed meal by C. funkei was improved by changing the inoculation amounts by 10% (108 cfu/mL), using a 1:0.5 material to water ratio at 35°C temperature for a 144 h reaction duration, which resulted in an 83.4% biodegradation of AFB1. In experiment 2, 112 one-day-old male Cherry Valley ducklings were randomly allocated to 4 experimental groups with 4 replicates of 7 birds each. For a period of 2 wk the controls received a base duckling diet (BD), a second group received a base diet contaminated with 10% AFB1 cottonseed meal (96.8 µg AFB1/kg), a third group was fed a base diet added with 5% unfermented and 5% fermented AFB1-contaminated cottonseed meal (57.0 µg AFB1/kg), and the fourth group was fed a base diet added with 10% AFB1-contaminated fermented cottonseed meal (16.0 µg AFB1/kg). The growth performance, relative organ weights, and serum biochemistry were analyzed. The results showed that the feed conversion ratio in the second group was lower than that of the controls at wk one and 2 (P < 0.05). Also, after 2 wk, group 2 ducklings had increased relative weights of the liver, kidneys, and spleen, increased activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), increased concentration of blood urea nitrogen (BUN) and creatinine (Crt), and decreased relative weight of Fabricius bursa (P < 0.05). In addition, the concentrations of total protein (TP) and albumin (ALB) in serum were also significantly higher at weeks one and 2 (P < 0.05). These alterations were attenuated or prevented when 5 or 10% fermented cottonseed meal substituted equal amounts of unfermented cottonseed meal in the diet. In conclusion, fermentation of AFB1-contaminated feed materials by C. funkei offers a new strategy to reduce the negative effects of aflatoxicosis in ducklings.

Three-dimensional reconstruction of mammalian 40 S ribosomal subunit.

The small (40 S) subunit from rabbit reticulocyte ribosomes has been reconstructed from electron micrographs of a negatively stained single-particle specimen to a resolution of 3.85 nm. The reconstruction reveals a morphology consisting of a broad wedge-shaped head structure set atop a quasi-cylindrical body. Distinctive features recognized in two-dimensional projections, such as the beak, back lobes, and feet, can now be localized in three dimensions. By reference to a recent reconstruction of the monomeric 80 S ribosome we can identify the interface and exterior surfaces of the subunit, thus enabling more detailed functional interpretations.

Protective effects of estradiol against amyloid beta protein-induced inhibition of neuronal Cl(-)-ATPase activity.

Low concentrations of amyloid beta proteins (Abetas, 1-10 nM) were recently demonstrated to reduce Cl(-)-ATPase activity in parallel with an increase in the intracellular Cl(-) concentration ([Cl(-)]i) and decreases in plasma membrane phosphorylated phosphatidylinositol (PIP and PIP2) levels in cultured rat hippocampal neurons. In this study, 17 beta-estradiol (estradiol) at a therapeutic concentration (1.8 nM) for Alzheimer's disease was found to block these Abeta (Abeta25-35)-induced changes. This protective effect of estradiol on Cl(-)-ATPase activity was antagonized by a pure estrogen receptor antagonist, ICI182780 and inhibitors for cyclic GMP-dependent protein kinase (PKG) (KT5823), Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) (KN62) and phosphatidylinositol (PI) 4-kinase (wortmannin and quercetin). Estradiol recovered Abeta-induced decreases in plasma membrane phosphoinositide (PIP and PIP2) levels, this effect being inhibited by KT5823 and KN62. Glutamate toxicity was augmented in neurons with elevated [Cl(-)]i either by Abeta-treatment or carbachol+KCl+LiCl-treatment. The increased glutamate toxicity in the Abeta-treated neurons was attenuated by estradiol. Thus, a therapeutic concentration of estradiol protected Abeta-treated neurons against inhibition of Cl(-)-ATPase activity and an increase in [Cl(-)]i through its receptor, probably via PKG- and CaMKII(-)mediated recovery of PI4P formation. Elevated [Cl(-)]i may be related to enhancement of glutamate toxicity.

Soybean isoflavone reduces the residue of zearalenone in the muscle and liver of prepubertal gilts.

The aim of the present study was to evaluate the protective effects of isoflavone (ISO) against zearalenone (ZEA) residues in the muscle and liver tissues of prepubertal gilts. Seventy 75-day-old, prepubertal, female pigs (Duroc × Landrace × Yorkshire, 26.5 ± 0.60 kg) were allocated randomly to seven diet treatments for 21days as follows: one control group (fed the basal diet) and six groups fed the basal diet with the addition of either 0.5 or 2.0 mg/kg ZEA plus either 0, 300 or 600 mg/kg ISO. The results showed that the diet with 2.0 mg/kg ZEA added caused an increase of ZEA residue level in muscle tissue (P < 0.05), and that the addition of both 0.5 and 2.0 mg/kg ZEA increased the residue level of ZEA in the liver of prepubertal gilts (P < 0.05). Addition of 600 mg/kg ISO to 2.0 mg/kg ZEA-contaminated diet decreased the ZEA residue level in liver tissue (P < 0.05), and the addition of 300 or 600 mg/kg ISO to the 2.0 mg/kg ZEA-contaminated diet decreased the residue levels of ZEA in muscle tissue (P < 0.05). Western blot analysis demonstrated that feeding ZEA to prepubertal gilts increased their protein expression of 3α/3ß-hydroxysteroid dehydrogenase (HSD; P < 0.05), and that the addition of 300 or 600 mg/kg ISO to the 2.0 mg/kg ZEA-contaminated diet decreased the protein expression of 3α/3ß-HSD (P < 0.05), compared with the addition of 2.0 mg/kg ZEA alone. The results demonstrated that muscle and liver tissues retain residual ZEA when pigs are fed a diet contaminated with high concentrations of ZEA, and that the concentration of ZEA in muscle and liver tissues increased with increased amounts of ZEA in the feed. In diets contaminated with high levels of ZEA, the addition of ISO may accelerate the biotransformation and degradation of ZEA and its metabolites, and reduce the residues of ZEA in liver and muscle tissues of prepubertal gilts.

Interaction of zearalenone and soybean isoflavone on the development of reproductive organs, reproductive hormones and estrogen receptor expression in prepubertal gilts.

The aim of the present study was to investigate the interactive effect of zearalenone (ZEA) and soybean isoflavone (ISO) on the development of reproductive organs, reproductive hormones and estrogen receptor expression in prepubertal gilts. Ninety 75-day-old female pigs (Duroc × Landrace × Yorkshire, 26.50 ± 0.60 kg) were randomly allocated to nine diet treatments during the 21 day study. The experiment employed a 3 × 3 factorial design using a non-soybean meal diet with addition of 0, 0.5 or 2.0mg/kg ZEA and 0, 300 or 600 mg/kg ISO. The results indicated that diets supplemented with 600 mg/kg ISO could reduce the increased weight of the reproductive organs induced by ZEA at 2mg/kg (P<0.05) while feed containing ISO and 0.5mg/kg ZEA increased the weight of the reproductive organs compared with pigs fed diets with 0.5mg/kg ZEA alone. Diets with ISO at 600 mg/kg reduced the large width of vulvas induced by diets with 2mg/kg ZEA (P<0.05). Simultaneous provision of ZEA and ISO to prepubertal gilts increased the level of E2 at days 7 and 14, but decreased it at day 21 (P<0.05). Pigs simultaneously fed 2mg/kg ZEA and 600 mg/kg ISO had the highest level of FSH (P<0.05). There was a significant interaction (P<0.05) between ZEA and ISO supplementation on the level of LH, and pigs offered diets with 2mg/kg ZEA and 600 mg/kg ISO had the lowest level of LH on days 14 and 21. Animals supplemented simultaneously with ZEA and ISO showed higher ERα/ERß mRNA expression compared to those offered diets containing 0.5mg/kg ZEA alone or basal diets. However, this simultaneous supplementation resulted in a lower level of ERα/ERß mRNA expression compared to offering diets with 2mg/kg ZEA alone. It appears that ISO can counteract the estrogenic influence of a high dosage of ZEA (2mg/kg). This affect might be attributed to competitive binding with estrogen receptors, thereby weakening the estrogenic effect of ZEA. Meanwhile, interactions between ZEA and ISO may interfere with the functioning of E2, FSH and LH in prepubertal gilts.

Decline of serum levels of free testosterone in aging healthy Chinese men.

OBJECTIVE: To investigate the age-related change of serum androgen levels in healthy men and to define a cut-off value of serum testosterone for the diagnosis of androgen deficiency in the aging male. METHOD: 1080 healthy men aged 20 to 70 years old were enrolled in Beijing, Shanghai, Xian and Chongqing. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), calculated free testosterone (cFT), sex hormone binding globulin (SHBG), 17beta-oestradiol (E2), the T/LH ratio, and T/SHBG as a free testosterone index (FTI) were all determined. RESULTS: Serum total T did not significantly decline, but the cFT, T/LH and FTI progressively decreased with aging. To determine androgen deficiency, the 10th percentile value of men < 40 years was defined as the lower cut-off value for cFT, T/LH or FTI, which were 0.3 nmol/L, 2.8 nmol/IU, and 0.4 nmol/IU respectively. With the median value of cFT of men aged between 20 and 49 years as the criterion, the level of cFT was lower in 2.82% of men from 40 to 49 years, in 19.53% from 50 to 59 years, in 22.57% from 60 to 69 years, and in 33.19% of men > or = 70 years. Taking the above value of cFT as the cut-off point, the prevalence of androgen deficiency in men 40-49 years was 13.0%, 31.8% in men 50-59 years, 30.1% in men 60 to 69 years, and 46.7% in men > 70 years. CONCLUSIONS: (i). While serum total T values do not decline with aging, the levels of cFT gradually decline with aging; (ii) when using the value of cFT of the 10th percentile of men aged 20 to 39 years as the cut-off point, the prevalence of androgen deficiency was < 15% before the age of 50 years, and about 30% thereafter, approaching 45% after the age of 70 years; and (iii) in this study the values of T/LH paralleled those of cFT closely; therefore, T/LH could serve as a surrogate for cFT.

The C-terminus and the Ca2+ low-affinity binding sites in bacteriorhodopsin.

Bacteriorhodopsin (bR) is found previously to have two high-affinity and four to six low-affinity Ca2+ binding sites. Our previous studies with site-directed mutation suggested that the two high-affinity sites are located within the protein and close to the retinal pocket. In order to investigate the location of the four to six low-affinity binding sites, we studied Ca2+ binding to deionized bR as well as its variant in which its C-terminus is removed by papain treatment. Potentiometric titration with Ca(2+)-selective electrodes were carried out and Scatchard plots were obtained from the titration data. We found that most of the low-affinity sites are eliminated upon removal of the C-terminus in bR. This suggests that the low-affinity sites in bR are on the surface. The involvement of the C-terminus in these sites is discussed.

Effect of linoleic acid hydroperoxide on endothelial cell calcium homeostasis and phospholipid hydrolysis.

The relationship between intracellular free calcium ion concentrations ([Ca2+]i) and release of arachidonic acid from membrane phospholipids following peroxidation was examined in rabbit aortic endothelial cells treated with linoleic acid hydroperoxide (LOOH). LOOH (0.1-0.4) mumol/10(6) cells) caused a rapid and dose-dependent transient increase in [Ca2+]i in the presence of extracellular Ca2+ that remained elevated over baseline for 15 to 30 s. In the absence of extracellular Ca2+, LOOH also evoked a transient increase in [Ca2+]i of lesser magnitude which immediately returned to basal (or below basal) levels. In this regard, the rise in intracellular Ca2+ after LOOH or vasopressin (AVP) treatments involved, at least in part, related intracellular pools that in each case was followed by influx of extracellular Ca2+. The intracellular membrane sources known to be affected by vasopressin were not directly involved. Most notably, the LOOH evoked rise in [Ca2+]i was not associated with release of IP3, suggesting that the source of intracellular Ca2+ is not IP3-sensitive pools. However, pretreatment with LOOH strongly inhibited the rise in [Ca2+]i upon subsequent addition of AVP or LOOH and the extent of such inhibition was dependent on the availability of free intracellular Ca2+ and presence of extracellular Ca2+. These findings suggest that reuptake of Ca2+ into intracellular membrane pools is reduced in the presence of LOOH and/or the availability of Ca2+ from agonist-sensitive sites is inhibited by LOOH. An increase in free 20:4 levels was found after LOOH treatment that was only partly prevented using intracellular Ca2+ chelators which maintained [Ca2+]i at basal levels after LOOH treatment. These findings suggest that LOOH induction of phospholipid hydrolysis proceeds following small transients in [Ca2+]i that are considerably less than that evoked by agents such as AVP, approximating basal Ca2+ concentrations. Inhibition of LOOH-induced lipid peroxidation by vitamin E also prevented the rise in [Ca2+]i and 20:4 release indicating that phospholipid hydrolysis is dependent, at least in part, on membrane lipid peroxidation. Inhibition of protein kinase C (PKC) completely blocked LOOH-induced release of 20:4 but had little effect on the LOOH-induced rise in [Ca2+]i, suggesting an indirect relationship between LOOH-induced membrane Ca2+ signalling events, with intervention via PKC-mediated induction of phospholipid hydrolysis. A rapid and progressive translocation of PKC to the membrane fraction was evident after LOOH addition over the time course corresponding to the maximal release of 20:4 which was also inhibited by vitamin E.(ABSTRACT TRUNCATED AT 400 WORDS)

The KKAy mouse: a model for the rapid development of glomerular capillary basement membrane thickening.

The renal tissue of 12-, 29-, 90- and 165-day-old genetically obese, hyperphagic, diabetic KKAy and age-matched nondiabetic C57BL/6 mice was morphometrically analyzed to characterize the development of peripheral glomerular capillary basement membrane thickening in the kidney of this animal model. Peripheral glomerular basement membrane (GBM) thickness was unremarkable in KKAy mice at 12 days of age (prior to onset of hyperinsulinemia) or at 29 days of age (after development of hyperinsulinemia). By 90 days of age, when the KKAy mice became severely hyperinsulinemic and hyperglycemic, the peripheral GBM thickness was greater (13%, p less than 0.002) in the diabetic compared with the nondiabetic mice. Furthermore, the peripheral GBM thickness was exacerbated (20%, p less than 0.001) by 165 days of age in the KKAy mice. The results of the present study suggest that peripheral glomerular capillary basement membrane thickening has an early onset and develops rapidly in the KKAy mouse in comparison with other diabetic animal models. Therefore, the KKAy mouse seems to be an appropriate model for further investigation of early structural and functional defects in the glomerular filtration barrier.

A Fourier-transform infrared spectroscopic comparison of cultured human fibroblast and fibrosarcoma cells: a new method for detection of malignancies.

Infrared vibration spectroscopy appears to be a more powerful technique for tumor diagnosis than visible or UV spectroscopy. In the present work, Fourier-transform infrared (FTIR) spectroscopy was used to compare cultured normal fibroblast and fibrosarcoma cells. Significant differences were observed by comparing the spectra of the normal human cells with that of the cancer cells. The PO2 symmetric stretching mode at 1082 cm-1 is shifted to a higher frequency in the cancer cell and a broad band, whose center is located at 1064 cm-1 in the cancer cell is reduced in intensity. In addition, the decrease in intensity of the CH2 bending mode relative to that of CH3 mode is detectable only in the fibrosarcoma cell. This FTIR difference between fibroblast and fibrosarcoma cells suggests that either fatty acid chains or protein side chains of the cancer cells are partially degraded resulting in more terminal carbon (e.g., CH3). It is also possible that changes in the environment upon carcinogenesis induces a change in the relative absorption cross section for CH3 and CH2 bending vibrations. These results suggest that FTIR spectroscopy may become a promising and sensitive technique for tumor identification.