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21.
Oocytes lose their developmental competence during prolonged storage of the ovary. In the present study, we supplemented the preservation solution for pig ovaries (phosphate buffered saline, PBS) with glucose and preserved the ovaries for 6 h at 25 C. Subsequently, we examined the glucose concentration of the follicular fluid (FF), pH of the FF, survival rate of the granulosa cells, and maturation and developmental competence of oocytes after storage. During storage, the glucose concentration of the FF (2.1 mM), pH of the FF (7.4), and survival rate of the granulosa cells (69.5%) rapidly decreased (glucose concentration: under 1.1 mM; pH: 6.8; and survival rate: 43%). On the other hand, when the preservation solution was supplemented with glucose (15 mM), the glucose concentration of the FF increased and the survival rate of the granulosa cells improved, although the pH of the FF decreased further (from 6.8 to 6.6). In addition, supplementation with glucose significantly improved the rates of oocytes at metaphase II (0 h: 65.0%; 6 h without glucose: 23.8%; and 6 h with glucose: 43.8%) and attenuated the decline in the rates of fertilization and development that resulted from prolonged storage, although there were no significant differences. In conclusion, modification of the preservation solution by the addition of glucose increased the glucose concentration of the FF and improved the rate of maturation of pig oocytes.  相似文献   
22.
Estrus induction is an important step in embryo production. It has been difficult to induce estrus in miniature pigs by intramascular (i.m.) injection of prostaglandin F2alpha (PGF2(2alpha)) in the early luteal stage of the estrous cycle. In the present study, we injected two different doses of PGF2(2alpha) i.m. and into the submucosa of the vaginal vestibule (i.ves.) of miniature pigs, and examined the effect of these treatments on estrus induction. Fifteen miniature pigs were divided into five experimental groups (control, saline injected i.m.; PGF2alpha treated, 1.0 or 1.5 mg of PGF2alpha injected twice i.m. or i.ves.), and the estrus length and concentrations of 17beta-estradiol (E2) and progesterone (P) in the blood were examined. Estrus length was significantly shortened by a large amount of PGF2alpha injected i.ves. In addition, the concentration of P in the blood significantly decreased after two injections of PGF2alpha (i.m. or i.ves.). These results suggest that in miniature pigs, administration of at least 3.0 mg of PGF2alpha is required for the induction of luteolysis and injection of PGF2alpha into the vaginal vestibule is a useful method of estrus induction.  相似文献   
23.
The infection of the feline T-lymphocyte cell line FeT-J with the feline immunodeficiency virus (FIV) Petaluma strain led to the establishment of nonvirus-producing cells. One clone (C15) obtained by limiting dilution was found to express FIV in response to chemical inducers of retroviruses. The chemical treatment of C15 cells led to not only FIV protein synthesis but also an augmentation of viral production. Examination of the C15 cell derivatives obtained by recloning revealed that 10-40% of treated cells constitutively expressed FIV antigens, whereas 100% with expressed FIV antigen in response to the inducer. Chemical induction resulted in more than a 100-fold increase in infectious viral production. The results suggest that a majority of FeT-J cells that are infected with FIV exist in a non-productive state. Establishing a cell line that can be non-productively infected by FIV may help determine the mechanisms of FIV latency.  相似文献   
24.
The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired.  相似文献   
25.
This study aimed to investigate the role of epithelial cells in regulating innate immunity in bovine oviduct epithelial cell (BOEC) culture. We studied the effect of Escherichia coli lipopolysaccharide (LPS) and its interaction with ovarian steroids, estradiol (E2) and progesterone (P4), and luteinizing hormone (LH) at concentrations observed during the preovulatory period on immune responses in BOEC culture. Immunohistochemistry of oviduct tissue showed intensive expression of Toll-like receptor-4 (TLR-4) and TLR-2 in epithelial cells. A dose of 10 ng/ml LPS stimulated TLR-4, cyclooxygenase-2 (COX-2), nuclear factor kappa B inhibitor A (NFKBIA), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) expression, indicating an early pro-inflammatory response. A dose of 100 ng/ml LPS did not induce expression of these genes but stimulated TLR-2, IL-10,IL-4 and microsomal prostaglandin E synthase-1 (mPGES-1) expression and PGE2 secretion, indicating an anti-inflammatory response. Ovarian steroids and LH completely block LPS (10 ng/ml)-induced TLR-4, IL-1β and TNF-α expression as well as LPS (100 ng/ml)-induced TLR-2 expression. Taken together, this study suggests the existence of an early signaling system to respond to infection in the BOEC. In addition, ovarian steroids and LH may play a critical role in inducing homeostasis and in controlling hyperactive pro-inflammatory responses detrimental to epithelial cells, sperm and the embryo.  相似文献   
26.
Age-associated deterioration in both the quality and quantity of mitochondria occurs in older women. The main aim of this study was to examine the effect of age on mitochondrial DNA copy number (mtDNA number) in early developmental stage bovine embryos as well as the dynamics of mtDNA number during early embryo development. Real-time PCR was used to determine mtDNA number. In vitro-produced embryos 48 h after insemination derived from Japanese black cows, ranging in age from 25 to 209 months were categorized based on their cleavage status. There was an overall negative relationship between the age of the cow and cleavage status, to the extent that the ratio of embryos cleaved over the 4-cell stage was greater in younger cows. The mtDNA number did not differ among the cleaved status of embryos. In the next experiment, oocytes collected from each donor cow were divided into 2 groups containing 10 oocytes each, in order to compare the mtDNA number of mature oocytes and early developmental stage embryos within individuals. Upon comparing the mtDNA number between oocytes at the M2 stage and early developmental stage 48 h post insemination, mtDNA number was found to decrease in most cows, but was found to increase in some cows. In conclusion, age affects the cleaving ability of oocytes, and very old cows (> 180 months) tend to have lower mtDNA numbers in their oocytes. The change in mtDNA number during early development varied among individual cows, although overall, it showed a tendency to decrease.  相似文献   
27.
The chemistry of runoff waters from 13 forested watersheds in six regions (four regions from Japan, one from southern China and one from northern Thailand) was evaluated. The Cl concentrations in runoff waters were higher in those watersheds which had closed canopies and were nearer to the ocean. The NO3 concentrations were higher in those watersheds having the developed soils and high moisture conditions, but were lower in tropical and subtropical regions for those watersheds which had high rates of nitrogen uptake and for watersheds with large areas of saturated soils. The SO4 2− concentrations were affected by SO4 2− adsorption properties of the soils: at Shibecha, Jiulianshan, and Chiang Mai with high adsorption capacities SO4 2− concentrations in streams were low. High SO4 2− concentrations were found at Mt. Hiei and Kagawa due to the weathering of sulfur minerals and high levels of atmospheric sulfur deposition. Within regions SO4 2− concentrations were inversely related to NO3 concentrations. A comparison among the watersheds suggested H+ consumption in deeper soil that increased pH and HCO3 concentrations of the runoff waters of some watersheds. Anion concentrations increased with low H.I. (Humidity Index) values suggesting that dry conditions increased concentrations due to high rates of evapotranspiration.  相似文献   
28.
Monoconidial strains of Venturia nashicola Tanaka et Yamamoto were isolated from Japanese or Chinese white pear trees which had never been treated with sterol demethylation inhibitors (DMIs) and their baseline sensitivities to fenarimol were determined by mycelial growth tests on fungicide-amended culture media. Strains were also obtained from Japanese pear orchards, which had been intensively treated with DMIs for several years and monitored for the shifts of fenarimol sensitivity in comparison with the baseline sensitivity. Results suggested slight shifts to lower fenarimol sensitivity in strains isolated from DMI-treated Japanese pear orchards. However, in inoculation tests on pear seedlings, fenarimol still provided adequate control of V. nashicola strains with reduced sensitivity to fenarimol in vitro, suggesting that the performance of this fungicide will still be maintained in the field. © 1998 Society of Chemical Industry  相似文献   
29.
Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high‐producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk‐meter and vacuum shut‐off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum.  相似文献   
30.
Three Japanese Black cows housed with 6 other cows exhibited main clinical symptoms of severe hemoglobinuria. Hematological analyses conducted after antibiotic therapy demonstrated severe anemia, and biochemical analyses indicated both severe hemolysis and disruption of hepatic function. One of the three cows died. Based on the above analyses and observation of typical clinical symptoms, a speculative diagnosis of bacillary hemoglobinuria was made, and immediate high-dose antibiotic treatment improved the general conditions of the surviving animals. Blood samples from the other 2 cows were collected sequentially after antibacterial therapy. Clostridium haemolyticum was detected by a nested polymerase chain reaction analysis of the blood samples. The cows were diagnosed with the second recorded occurrence of bacillary hemoglobinuria in Japan.  相似文献   
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