Development of bovine oocytes reconstructed with different donor somatic cells with or without serum starvation

We conducted this study to examine whether serum starvation in culture contributes to better development of bovine reconstructed oocytes and to evaluate which serum-starved somatic cell is the most effective for cloned calf production. In Experiment 1, donor cells of four different types (cumulus cells, ear fibroblasts, oviduct cells and uterine cells) were either serum-starved or not before fusion with enucleated oocytes, and reconstructed oocytes were further cultured for 168 h. Regardless of serum starvation, cumulus cells or ear fibroblasts yielded higher (P < 0.05) rates of fusion than other cells (62.6-69.3 versus 33.3-38.7%). In the serum-starved group, the first cleavage after reconstruction was significantly increased in cumulus cells and ear fibroblasts, compared with oviduct cells (93.4-94.3 versus 78.8-86.0%), and oocytes reconstructed with either of these yielded more blastocysts than oocytes reconstructed with oviduct or uterine cells (40.6-43.8 versus 20.3-19.0%). We observed a similar pattern in the non-starved group, but we found a significant increase in blastocyst formation was found only in cumulus cells compared with other donor cells (42.6 versus 15.4-27.7%). Overall comparison showed that serum starvation increased the rates of cleavage and development to the blastocyst stage, but we found a statistical significance only in the cleavage rate (80.0 versus 89.5%). In Experiment 2, we transferred randomly selected 59 blastocysts that were developed from oocytes reconstructed with serum-starved cells to 44 synchronised recipients. Of those recipients, 23 became pregnant on Day 60 after transfer (52.3%) and 12 (27.3%) delivered cloned calves. The mean gestation length and birth weight was 275 +/- 8 days and 39.6 +/- 15.6 kg, respectively. Although there was no significant difference among donor cells, blastocysts that were derived from oocytes reconstructed with ear fibroblasts yielded the highest rates of pregnancy (50.0%) and delivery (27.3%). In conclusion, serum starvation is effective for improving preimplantation development of oocytes reconstructed with cumulus or ear fibroblast cells and it may positively influence on obtaining better pregnancy outcome.

Isolation and characterization of the ethynylestradiol-biodegrading microorganism Fusarium proliferatum strain HNS-1

We cultivated hundreds of sediment, soil, and manure samples taken from rivers and farms in a medium containing ethynylestradiol (EE2) as the sole source of carbon, so that microorganisms in the samples would acclimatize to the presence of EE2. Finally, we isolated an EE2-degrading microorganism, designated as strain HNS-1, from a cowshed sample. Based on its partial nucleotide sequence (563 bp) of the 28S rRNA gene, strain HNS-1 was identified as Fusarium proliferatum. Over 15 days, F. proliferatum strain HNS-1 removed 97% of EE2 at an initial concentration of 25 mg.L-1, with a first-order rate constant of 0.6 d-1. Unknown products of EE2 degradation, which may be more polar compounds that have a phenolic group, remained in the culture medium.

Nutritive and economic values of high oil corn in layer diet

Two layer feeding trials were conducted to demonstrate the nutritive and economic values of recently developed high oil corn (HOC) in Korea. A corn-soybean meal-based commercial layer diet was chosen as the control diet. The yellow dent corn in the control diet was replaced with HOC to give an isocaloric diet, or replaced with HOC on a 1:1 basis to give a high energy diet. In Trial 1, 510 23-wk-old ISA Brown layers were allotted to three dietary treatments with five replicates per treatment. In Trial 2, 600 38-wk-old Hy-Line Brown layers were allotted to three dietary treatments, again with five replicates per treatment. Both trials were conducted for 15 wk. To measure the ME values of typical corn and HOC, two metabolism trials were performed with layers and adult roosters. The HOC used in this trial contained approximately 94% higher crude fat (6.60% as-fed basis) compared with typical corns. The gross energy, AMEn, and TME values of HOC, are 5.7 to 7.7% higher than those of typical corns, indicating that the energy use of each corn were similar. Oil from the HOC contains 6.5 to 8.3% more oleic acid and 6 to 7% less linoleic acid than oil from typical corns. HOC feeding, on an isocaloric basis or on 1:1 replacement with typical corn, did not exert any effect on various laying performances, including the physical quality of egg. This result reflects the quality of the commercial diet chosen as the control diet, which was already fairly good, such that the performance was already maximal. The polyunsaturated fatty acid content in yolk from hens fed HOC was higher than that from hens fed typical corns, reflecting higher linoleic acid content in the HOC. HOC feeding decreased the saturated fatty acid content in the yolk, due primarily to decreased palmitic acid. If used alone replacing typical corn completely in a layer diet, the acceptance price of HOC was estimated to be 154 won/kg when the price of typical corn was 131 won/kg (118:100). When both corns were allowed to be used, the acceptance price of HOC increased to 184 won/kg (140:100), indicating that a lot cheaper layer diet can be formulated when both HOC and typical corn are used in laying hen diet formulation.

A hybrid fenton oxidation-microbial treatment for soil highly contaminated with benz(a)anthracene

In order to mitigate the strong microbial resistance of benz(a)anthracene [B(a)A] in soil, a hybrid treatment of Fenton oxidation followed microbial culture was carried out. Based on optimal Fenton oxidation. i.e., 1.0 ml of ethanol, 0.2 ml of 0.5 M Fe2+, and 0.3 ml of 30% H2O2 per 1 g of 500 mg B(a)A/kg soil, about 43% of B(a)A-7,12-dione was generated during oxidation of 97% B(a)A. When the comparative biodegradability between B(a)A-contaminated soil and B(a)A-contaminated soil after Fenton oxidation was examined, it was found that 98% of B(a)A-7,12-dione degraded after 63 d in comparison with only 12% of B(a)A over the same period; results demonstrating that Fenton oxidation enhances biodegradability of B(a)A through B(a)A-7,12-dione.

Fenton oxidation of ethanol-washed distillation-concentrated benzo(a)pyrene: reaction product identification and biodegradability

After multiple ethanol washings followed by distillation, concentrated benzo(a)pyrene (B(a)P) in ethanol (approximately 85 mg L(-1)) was treated by Fenton oxidation, where > 99.8% of B(a)P was removed under a pseudo-first-order reaction. GC-MS and HPLC analysis identified B(a)P-1,6-, -3,6-, and -6,12-dione as Fenton oxidation products; all of which are known to have lower toxicity than B(a)P. Microbial resistance experiments demonstrated that B(a)P-1.6-, -3.6-, and -6,12-dione are more easily degraded than B(a)P. These results indicate that the proposed treatment can be effectively applied to remediate B(a)P-contaminated soil.

Localization of phospholipase C-gamma1 signaling in caveolae: importance in EGF-induced phosphoinositide hydrolysis but not in tyrosine phosphorylation

Upon epidermal growth factor treatment, phospholipase C-gamma1 (PLC-gamma1) translocates from cytosol to membrane where it is phosphorylated at tyrosine residues. Caveolae are small plasma membrane invaginations whose structural protein is caveolin. In this study, we show that the translocation of PLC-gamma1 and its tyrosine phosphorylation are localized in caveolae by caveolin-enriched low-density membrane (CM) preparation and immunostaining of cells. Pretreatment of cells with methyl-beta-cyclodextrin (MbetaCD), a chemical disrupting caveolae structure, inhibits the translocation of PLC-gamma1 to CM as well as phosphatidylinositol (PtdIns) turnover. However, MbetaCD shows no effect on tyrosine phosphorylation level of PLC-gamma1. Our findings suggest that, for proper signaling, PLC-gamma1 phosphorylation has to occur at PtdInsP(2)-enriched sites.

Photocatalytic degradation of gaseous perchloroethylene: products and pathway

Batch photocatalytic degradation of 1000-ppm gaseous perchloroethylene (PCE) was conducted with UV irradiation such that nearly 100% was decomposed within 10 min. The main intermediate and final product were identified as trichloroacetylchloride (TCAC) and hydrogen chloride (HCl), respectively, and minor ones as dichloroacetic acid (DCAC), monochloroacetic acid (MCAC), carbon tetrachloride, chloroform, and phosgene. More than 90% of Cl- equivalent, i.e., the sum of the chlorine number in PCE, intermediates, and HCl, was compensated for during the time of PCE degradation; a result indicating that no other major chlorinated intermediates are present during the time of PCE degradation. In a similar experiment, 500 ppm of gaseous TCAC degraded into HCl within 3 h without producing DCAC or MCAC, where like PCE, more than 90% of Cl- equivalent, i.e., the sum of the chlorine number in TCAC and HCl, was compensated for during time of TCAC degradation. Accordingly, gaseous PCE is concluded to predominantly follow a degradation pathway of PCE --> TCAC --> HCl.

Prediction of Fenton oxidation positions in polycyclic aromatic hydrocarbons by Frontier electron density

Five recalcitrant polycyclic aromatic hydrocarbons (PAHs) in ethanol were subjected to Fenton oxidation, and following GC-MS identification of respective oxidation products, their oxidation positions were compared to those predicted by Frontier electron density. Quinone forms of oxidation products were identified in each PAH. With the exception of fluorene, oxidation positions of quinone forms of products of acenaphthylene, anthracene, benz(a)anthracene, and benzo(a)pyrene corresponded with predicted positions in which Frontier electron density was high. From these results, it appears that determining the Frontier electron density of a PAH is a promising method for predicting the Fenton oxidation position.

Bradykinin activates phospholipase D2 via protein kinase cdelta in PC12 cells

Bradykinin (BK) activates phospholipase D (PLD) and induces several responses such as catecholamine secretion, collapse of growth cones, and gene expression in PC12 pheochromocytoma cells. Although two distinct PLD isozymes, PLD1 and PLD2, have been cloned from mammalian cells, the regulatory mechanism for each PLD isozyme by BK is not clear. In our present study, we investigated the activation mechanism of PLD2 by BK in PLD2-overexpressing PC12 cells. BK stimulated PLD2 activity in a concentration-dependent manner within 1 min and this activation was inhibited by pretreatment of the cells with protein kinase C (PKC) inhibitor. PKCalpha and PKCdelta translocated from cytosol to membrane upon BK treatment, and rottlerin potently inhibited the activation of PLD2 by BK. These results suggest that BK activates PLD2 via PKCdelta in PC12 cells.

Phospholipase D2 activity suppresses hydrogen peroxide-induced apoptosis in PC12 cells

Phospholipase D (PLD) plays an important role as an effector in the membrane lipid-mediated signal transduction. However, the precise physiological functions of PLD are not yet well understood. In this study, we examined the role of PLD activity in hydrogen peroxide (H(2)O(2))-induced apoptosis in rat pheochromocytoma (PC12) cells. Treatment of PC12 cells with H(2)O(2) resulted in induction of apoptosis in these cells, which is accompanied by the activation of PLD. This H(2)O(2)-induced apoptosis was enhanced remarkably when phosphatidic acid production by PLD was selectively inhibited by pretreating the PC12 cells with 1-butanol. Expression of PLD2, but not of PLD1, correlated with increased H(2)O(2)-induced PLD activity in a concentration- and time-dependent manner. Concomitant with PLD activation, the PLD2 activity suppressed H(2)O(2)-induced apoptosis in PC12 cells. Expression of PLD2 lipase-inactive mutant (K758R) had no effect on either PLD activity or apoptosis. PLD2 activity also suppressed H(2)O(2)-induced cleavage and activation of caspase-3. Taken together, the results suggest that PLD2 activity is specifically up-regulated by H(2)O(2) in PC12 cells and that it plays a suppressive role in H(2)O(2)-induced apoptosis.

Phospholipase D1 is phosphorylated and activated by protein kinase C in caveolin-enriched microdomains within the plasma membrane

Activities of phospholipase D (PLD) in diverse subcellular organelles have been identified but the details of regulatory mechanisms in such locations are unknown. Protein kinase C (PKC) is a major regulator of PLD. Serine 2, threonine 147, and serine 561 residues of phospholipase D1 (PLD1) were determined as sites of phosphorylation by PKC (Kim, Y., Han, J. M., Park, J. B., Lee, S. D., Oh, Y. S., Chung, C., Lee, T. G., Kim, J. H., Park, S. K., Yoo, J. S., Suh, P. G., Ryu, S. H. (1999) Biochemistry 38, 10344-10351). In our present study, a triple mutation of these phosphorylation sites diminished markedly phorbol 12-myristate 13-acetate (PMA)-induced PLD1 activity in COS-7 cells. We looked at the location of the PLD1 phosphorylation by PKC by observing PMA induced band shifts and by use of anti-phospho-PLD1 monoclonal antibody. The shifted PMA-induced proteins and the immunoreactivity of the anti-phospho-PLD1 antibody were mainly found in the caveolin-enriched membrane (CEM) fraction. Depletion of cellular cholesterol led to a loss of this compartmentalization of phosphorylated PLD1 in the CEM. Replacement of the cellular cholesterol led to the restoration of phosphorylated PLD1 in the CEM. Immunocytochemical studies of COS-7 cells revealed that PLD1 was localized in the plasma membrane as well as in the vesicular structures in the cytoplasm, but the phosphorylation of PLD1 occurred only in the plasma membrane. Our results, therefore, show that phosphorylation, and thereby activation, of PLD1 by PKC occurs in the caveolin and cholesterol-enriched low density domain of the plasma membrane in COS-7 cells.

Hydrogen peroxide-induced phospholipase D2 activation in lymphocytic leukemic L1210 cells

Extracellular hydrogen peroxide (H2O2) has been implicated in the activation of phospholipase D (PLD). However, it was still unclear how this activation occurs and what the molecular identity of the H2O2-stimulated PLD isozyme is. This study shows that H2O2 potently increases the PLD activity in mouse lymphocytic leukemic L1210 cells, which contain exclusively PLD2. In addition, H2O2 increased PLD activity only in PLD2-transfected COS-7 cells and not in PLD1-transfected cells. This suggests that PLD2 is selectively activated by H2O2. Depletion of extracellular Ca2+ with EGTA completely blocked the H2O2-induced PLD activation, indicating that Ca2+ influx is required. Moreover, pretreatment of the cells with the protein kinase C (PKC) inhibitors GF-109203X and RO-31-8220 and down-regulation of PKCalpha by prolonged treatment with 4beta-phorbol 12-myristate 13-acetate inhibited the H2O2-stimulated PLD2 activity, which points to the involvement of PKCalpha. Based on these new findings we suggest that PLD2 activity is specifically up-regulated by H2O2 and that the H2O2-induced PLD2 activation is mediated by Ca2+ influx and PKCalpha activation.

Cytosolic phospholipase A2-mediated regulation of phospholipase D2 in leukocyte cell lines

Phospholipase D (PLD) has been implicated in a variety of cellular processes, including inflammation, secretion, and respiratory burst. Two distinct PLD isoforms, designated PLD1 and PLD2, have been cloned; however, the regulatory mechanism for each PLD isoform is not clear. In our present study we investigated how PLD2 activity is regulated in mouse lymphocytic leukemia L1210 cells, which mainly contain PLD2, and in PLD2 -transfected COS-7 cells. Intriguingly, A23187, a calcium ionophore that induces calcium influx, potently stimulates PLD activity in these two cell lines, suggesting that Ca2+ might be implicated in the regulation of the PLD2 activity. In addition to the A23187-induced PLD2 activation, A23187 also increases PLA2-mediated arachidonic acid release, and the A23187-stimulated PLD2 and PLA2 activities could be blocked by pretreatment of the cells with cytosolic calcium-dependent PLA2 (cPLA2) inhibitors, such as arachidonyl trifluoromethyl ketone and methyl arachidonyl fluorophosphonate in these two cell lines. Moreover, the A23187-induced PLD2 and PLA2 activities could be inhibited by cotransfection with antisense cPLA2 oligonucleotide. These results suggest a role for cPLA2 in the regulation of PLD2 activity in vivo. The inhibitory effect of arachidonyl trifluoromethyl ketone on the A23187-induced PLD2 activity could be recovered by addition of exogenous lysophosphatidylcholine. This study is the first to demonstrate that PLD2 activity is up-regulated by Ca2+ influx and that cPLA2 may play a key role in the Ca2+-dependent regulation of PLD2 through generation of lysophosphatidylcholine.

Removal of low concentrations of carbon tetrachloride in compost-based biofilters operated under methanogenic conditions

Research was performed to demonstrate the removal of carbon tetrachloride (CT) using compost biofilters operated under methanogenic conditions. Biofilters were operated at an empty-bed residence time of 2.8 minutes using nitrogen as the atmosphere. Hydrogen and carbon dioxide were supplied as an electron donor and carbon source, respectively, during acclimation of the bed medium microbes. Once methanogenesis was demonstrated, CT flow to the biofilter was established. Biofilters were operated over a CT concentration range from 20 to 700 ppbv for 6 months. Bed medium microbes were able to remove up to 75% of the inlet CT. At excessively high CT concentrations (> 500 ppmv), methane production and hydrogen utilization by the bed medium microbes appeared to be inhibited. CT removal by the biofilter decreased when the hydrogen supply was removed from the biofilter inlet, indicating that hydrogen acted as the electron donor for reductive dechlorination. The removal efficiency and relatively low empty bed residence times demonstrated by these laboratory-scale biofilters indicate that anaerobic biofiltration of CT may be a feasible full-scale process.

Effects of feather cover and insulative jackets on metabolic rate of laying hens

Two experiments were conducted to determine the influence of feather cover and newly-devised insulative jackets on the heat production in Single Comb White Leghorn laying hens at 20 C. An open-circuit calorimeter was used to measure the gaseous exchange of the birds. With ad libitum feeding, birds with clipped back and breast feathers produced 6% more heat than did normally feathered hens. This difference was removed by placing jackets on the defeathered birds. The jackets also decreased the surface temperature of the feather-clipped areas, indicating an effective insulation. When the jackets were applied to naturally poor-feathered hens, fasting heat production decreased significantly, but not to the base level of that of normally feathered hens.

Effect of the addition of varied salt levels on the performance of growing chickens fed rye diets

A series of feeding trials were conducted with Single Comb White Leghorn cockerels and broiler chickens to determine if salt per se was a contributing factor in the growth-depressing properties of rye. When added salt level increased from .3 to .6% in rye-based diets growth rate and feed conversion efficiency in young chickens improved significantly (P less than or equal to .05) but not to that of corn-fed birds. The relative growth rate of chickens fed rye diets containing .3% added salt was 78 to 86% of that of birds fed rye diets with .6% added salt.

Influence of rye and dietary salt level on water and sodium metabolism in intact and colostomized roosters

A study of water and Na metabolism was conducted with 24 roosters fed diets based on either corn or rye with two levels (.4 and 1.0%) of added salt. A diet containing water-extracted rye and a diet based on corn with a freeze-dried water extract of rye added at a level of 12% were also used in the study. Measurements were made on intact and colostomized roosters. In intact roosters dry matter metabolizability was depressed when rye diets were compared with corn diets. Measurements in feces from colostromized roosters fed rye as compared to those fed corn indicated that moisture, viscosity, and water holding capacity were increased and that bulk density was decreased. Diet salt level did not influence the responses regarding these parameters, but water extraction of rye completely alleviated the effects of rye on dry matter metabolizability and viscosity and partially reduced the influence of rye on fecal moisture while not altering the responses regarding water holding capacity or bulk density of feces. With the exception of feces moisture, the water extract of rye had no influence regarding these parameters. Roosters fed rye in comparison to those fed corn showed increases in water intake and excreta moisture content and decreases in urine sodium concentrations and plasma clearance of sodium. The response to rye regarding these latter parameters was dependent on diet salt level. The data indicated a reduced availability of sodium at the cellular level in rye-fed birds, which was manifest in a difference in route of excretion of sodium such that urine was the major route in corn-fed birds and feces was the major route for birds fed rye. The dietary fiber content of rye appeared to be a major factor in rye influencing sodium availability.