Mouse scrapie and polyadenylated RNA metabolism in L cells     

Alistair J. Lax  E.Jane Manning  Michael C. Clarke  Richard H. Kimberlin 《Veterinary microbiology》1981,6(4):375-378

It has previously been reported that infection of mice with the scrapie agent alters polyadenylated RNA (poly (A) RNA) metabolism. In particular, it was claimed that incubation of L cells with extracts from scrapie-infected mice changed the level of poly (A) RNA in the L cells. We have attempted to repeat this work, using the original techniques, but have been unable to confirm the published findings. Furthermore our work suggests that the techniques used would not have yielded purified poly (A) RNA, and analysis of the data from the previous publications supports this view.  相似文献   

Metabolism of methylated analogs of aldrin and dieldrin by liver preparations from male and female rat     

K.A. Hassall  A. Dionyssiou-Asteriou  D. Manning 《Pesticide biochemistry and physiology》1978,8(3):287-301

Analogs of aldrin and dieldrin have been synthesized, the molecules of which lack a methylene bridge but have two methyl groups attached to olefinic or oxirane ring carbon atoms. Their metabolism was studied using NADPH-supplemented 12,000g × 30-min supernate of livers from Wistar and CD strains of rats. The dimethylated olefin was not metabolized to its epoxide but was converted by supernate of liver from rats of both sexes to a labile hydroxylated metabolite. Exogenous NADPH increased the rate at which the olefin was metabolized, but concentrations of NADPH which increased the yield of the labile metabolite when added to female rat liver preparations decreased the yield when added to those from the male. This metabolite had a mass spectrum which was consistent with it being a hydroxymethyl derivative. The dimethylated epoxide was metabolized more slowly than the olefin, and a notable sex difference in the route of metabolism was evident. With supernate from livers of female rats the only metabolite detected by gas-liquid chromatography had a mass spectrum consistent with it being a ring-hydroxylated epoxide. Male rat liver supernate formed small quantities of the same compound, but the major metabolite had a mass spectrum indicative of a hydroxymethyl epoxide. No hydrolysis of the oxirane ring of the epoxide has been detected. The relevance of these results to the planned synthesis of cyclodienes of optimal biodegradability is mentioned.  相似文献   

Stressor effects of handling on the immature fowl.     

B M Freeman  A C Manning 《Research in veterinary science》1979,26(2):223-226

Chicks were handled for 5 min twice daily for five consecutive days per week over a three-week period. The control birds were not handled once they had been allotted to their brooders. The growth rate of the treated birds was significantly decreased. There was no adrenal hypertrophy; the concentration, but not the content, of adrenal cholesterol was significantly increased. Plasma glucose, FFA and cholesterol concentrations were similar in the groups at the end of the experiment. The lipolytic response of the handled birds to a further stimulus of handling was significantly greater than that of unhandled birds experiencing novel handling stimulus. There was also a significant decrease in the concentration of corticosterone in the plasma of the handled birds but not in the unhandled group. There was thus no evidence of habituation.  相似文献   

Group-Housing of Lactating Sows - Effects on Reproductive Performance     

AM Dalin  F Hultén 《Reproduction in domestic animals》1998,33(3-4):103-106

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Cumulus–Oocyte Communications in the Horse: Role of the Breeding Season and of the Maturation Medium     

S Colleoni  AM Luciano  F Gandolfi 《Reproduction in domestic animals》2004,39(2):70-75

Horse is a seasonal breeder and information on oocyte quality outside the breeding season is very limited. Ovaries obtained at the slaughterhouse are a convenient but often limited source of oocytes in this species. As the low quantity of ovaries leads to an intensive use of all available material, it would be useful to know whether ovaries collected during the non‐breeding season are suitable for in vitro maturation (IVM). In an attempt to characterize the effect of season on oocyte quality, we investigated the permeability of the gap junctions (GJ) present between cumulus cells and oocytes because of their important role in oocyte growth and maturation. We also compared the effect of supplementing the maturation medium with bovine serum albumin (BSA) or oestrus mare serum (EMS). A total of 645 oocytes isolated from 158 and 154 ovaries collected during the breeding and the non‐breeding season, respectively, were used in this study. Oocytes were matured for 30 h in TCM 199 supplemented either with 10% EMS or with 4 mg/ml BSA. The presence of permeable GJs between cumulus cells and oocytes was investigated with the injection of a 3% solution of the fluorescent dye Lucifer yellow into the ooplasm. No differences in efficiency of oocyte retrieval or oocyte meiotic competence were detected between oocytes collected during the breeding and non‐breeding season. The vast majority (90%) of the oocytes collected during the breeding season had fully functional communications with their surrounding cumulus cells but such communications were completely interrupted in 55.3% of the oocytes collected during the non‐breeding season. During the non‐breeding season, the proportion of oocytes whose communications with cumulus cells were classified as closed or intermediate at the end of maturation was lower in the group matured with BSA than with EMS (71.4 vs 97.7, p < 0.05). The same trend, although not statistically significant, was observed during the breeding season also. The presence of BSA caused an incomplete cumulus expansion during both seasons. Our data indicate that oocytes collected during the non‐breeding season do not show any meiotic deficiency but lack active communication with the surrounding cumulus cells at the time of their isolation from the ovary. No data are available at present for determining the consequences on the developmental competence even if data from other species suggest that this is likely.  相似文献   

Alkaline and Acid Phosphatase, β‐Glucuronidase and Electrolyte Levels in Fractionated Stallion Ejaculates     

AM Kareskoski  T Reilas  S Sankari  M Andersson  K Güvenc  T Katila 《Reproduction in domestic animals》2010,45(6):e369-e374

Seminal plasma (SP) is a mixture of contents from the testes, epididymides and accessory sex glands. The sperm concentration is highest in the first few jets, or fractions, of the ejaculate, and the composition of SP varies between these fractions because accessory gland secretions are released in a specific order. The aim of this study was to compare the levels of Na, Cl, K, Mg, Ca, inorganic phosphate (Pi) and the enzymes alkaline phosphatase (AP), acid phosphatase (ACP) and β‐glucuronidase (BG) in the different fractions of the ejaculate and in different stallions. All semen collections were done using a computer‐controlled phantom that collects the ejaculatory jets separately in five cups. The cups with the highest (HIGH) and the lowest (LOW) sperm concentration were analysed. In Trial I, semen was collected from three reproductively normal stallions. In Trial II, ejaculates of two reproductively normal stallions were compared to those of two subfertile stallions. In Trial III, semen was collected from seven stallions with varying reproductive history. The sperm‐rich fractions contained the highest levels of AP, ACP, BG and inorganic phosphate, and the values were positively correlated to the sperm concentration. Significant differences between the subfertile and the fertile stallions pairs in HIGH : LOW ratios were found in Pi and Cl concentrations. The highest concentrations of Ca and Mg were found in the last fractions with low sperm concentrations, with no significant differences between the fertile and the subfertile stallion pairs. The concentrations of K, Na and Cl were similar in HIGH and LOW fractions and in whole ejaculate samples. Pre‐sperm fluid contained the highest concentrations of Na and Cl. Some of the possible variation in storage tolerance between ejaculates and ejaculatory fractions could perhaps be explained by differences in the composition of SP.  相似文献   

Effect of Dietary Total Protein and Animal Protein on Growth and Feed Efficiency of Juvenile Channel Catfish Ictalurus punctatus and Their Response to Edwardsiella ictaluri Challenge     

Menghe H.  Li  David J.  Wise  Bruce B.  Manning Edwin H.  Robinson 《Journal of the World Aquaculture Society》2003,34(2):223-228

A laboratory study was conducted to evaluate effects of dietary total protein and animal protein source and concentration on growth and feed efficiency of juvenile channel catfish Ictalurus punctutus and their response to Edwardsiellu ictuluri challenge. Eight diets evaluated were: three diets containing either 28, 32, or 36% crude protein with 6% menhaden fish meal and 6% meat and bonehlood meal and five diets containing 32% crude protein with either no animal protein, 68 or 12% menhaden fish meal, or 6% or 12% meat and bonehlood meal, respectively. Twenty channel catfish with an average weight of 6.6 g/fish were stocked into each of forty 110-L flow-through aquaria (five aquaridtreatment). Fish were fed to approximate satiation twice daily for 9 wk. Fish in each tank were then exposed to E. ictaluri . There were no differences in feed consumption, weight gain, feed efficiency, and survival before and after challenge among fish fed diets containing 28, 32, or 36% protein with 6% menhaden fish meal and 6% meat and bone/ blood meal. Fish fed a 32% all-plant protein diet had weight gain and feed efficiency similar to fish fed diets containing 12% menhaden fish meal, but had a higher weight gain than fish fed a 32% protein diet containing 6% meat and bonehlood meal. No significant differences were observed in survival after E. ictuluri challenge among fish fed diets containing the various levels of animal proteins. Results indicate that dietary protein levels varying from 28% to 36% do not appear to affect growth, feed efficiency. and E. icraluri resistance or susceptibility in fingerling channel cattish fed to satiation and raised from approximately 7 to 56 g under laboratory conditions. Data also demonstrate that a 32% all-plant protein diet can be fed to small fingerling channel catfish without adversely affecting growth, feed efficiency, or resistance to E. ictuluri .  相似文献   

Stress of transportation for broilers   总被引：3，自引：0，他引：3  

B M Freeman  P J Kettlewell  A C Manning  P S Berry 《The Veterinary record》1984,114(12):286-287

Transporting birds for two to four hours over distances of up to 224 km (140 miles) induced hyperlipacidaemia and hypoglycaemia while the concentration of plasma cholesterol decreased and then increased significantly. These responses were the same in summer and winter. Body temperature was not affected by the experimental conditions. There was a consistent increase in plasma corticosterone which was greater in winter than in summer.  相似文献   

Postovulatory Effect of Intravenous Administration of Lipopolysaccharide (E. coli,O55:B5) on the Contractile Activity of the Oviduct,Ova Transport,Binding of Accessory Spermatozoa to the Zona Pellucida and Embryo Development in Sows     

AM Mwanza  H Rodríguez‐Martínez  H Kindahl  S Einarsson 《Reproduction in domestic animals》2002,37(5):269-274

The effect of lipopolysaccharide (LPS) (E. coli, O55:B5), administered 18 h after ovulation in the second oestrus after weaning, on the contractile activity of the oviduct, ova transport, sperm binding to zona pellucida (ZP) and embryo development, was studied in 14 Swedish crossbred (Landrace Yorkshire) multiparous sows. The endotoxin group (E‐group) sows were administered with 300 ng/kg of LPS while the control group (C‐group) sows were administered with 5 ml of saline i.v. via an indwelling jugular cannula. Immediately after evidence of standing oestrus, a Millar^® pressure transducer was placed intraluminally about 3 cm into the mid‐isthmus, via laparotomy. Pressure recordings of the oviduct were collected from all conscious sows until slaughter. After slaughter, the genital tract opposite to the side with the transducer was retrieved, and three equal isthmic segments and the first third of the uterine horn part adjacent to the utero‐tubal‐junction (UTJ) were flushed separately to recover the ova. The intervals (mean±SD) from ovulation to slaughter (OS) and insemination to ovulation (IO) were not different between the E‐group (44.5±5.7 h; 13.3±6.5 h) and the C‐group (42.7±5.9 h; 14.8±4.1 h), respectively. Ova recovery rate (RR) in the E‐group (80.2±22.9%) did not differ from that in the C‐group (85.2±4.5%). The frequency distribution of ova recovered in the different segments did not significantly (p>0.05) differ between the groups. The E‐group showed higher cleavage rate than controls. A higher proportion of spermatozoa bound to the ZP was also found in the E‐group compared with controls. The isthmic intraluminal pressure slightly increased (p=0.07) 18 h after ovulation and immediately following LPS in the E‐group, compared with the C‐group. The frequencies of phasic pressure fluctuations were significantly (p<0.05) lower at 30 and 38 h after ovulation in the E‐ than in the C‐group. It can be concluded from the present study that a single i.v. administration of LPS (300 ng/kg body weight) to sows, 18 h after ovulation might be associated with changes in isthmic pressure and the frequency of phasic pressure fluctuations, increased numbers of spermatozoa attached to the ZP and an enhanced embryo development but not with ova transport rates.  相似文献   

Effect of anaerobic cecal microflora and dietary lactose on colonization resistance of layer chicks to invasive Salmonella enteritidis.   总被引：4，自引：0，他引：4  

D E Corrier  B Hargis  A Hinton  D Lindsey  D Caldwell  J Manning  J DeLoach 《Avian diseases》1991,35(2):337-343

The effect of oral inoculation with anaerobic cultures of cecal microflora and providing lactose in the feed on colonization resistance to invasive Salmonella enteritidis was evaluated in newly hatched leghorn chicks. Salmonella colonization of the ceca, tissue invasion and organ colonization, horizontal transmission, and seroconversion were significantly decreased (P less than 0.01) in chicks inoculated with cecal flora. The addition of lactose to the feed, in the absence of cecal microflora, failed to provide protection. Dietary lactose enhanced colonization resistance in chicks that were inoculated with anaerobic cultures of cecal flora. The results indicated that establishment of normal cecal flora in layer chicks together with the addition of lactose to the diet markedly increases resistance to cecal colonization and organ invasion, and decreases horizontal transmission of S. enteritidis.  相似文献