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1.
Outer dense fibres (ODF) are important substructures of mammalian sperm tails that are involved in the regulation of sperm motility. In this study, we investigated the identity of several sodium dodecyl sulphate (SDS)‐insoluble ODF proteins. Bovine ODF were purified by separating sperm heads and tails using ultrasound and Percoll® density gradient centrifugation. Sperm flagella were treated with the detergent cetyltrimethylammonium bromide (CTAB). CTAB‐insoluble material, which reportedly represents the ODF fraction, was collected, and electron microscopy confirmed a highly purified ODF fraction. We found after solubilization of this fraction with SDS that high amounts of insoluble material were retained after centrifugation. SDS‐insoluble material was collected and quantitatively dissolved in 8 M urea. SDS‐gel electrophoresis in the presence of urea revealed polypeptides with apparent molecular masses of approximately 25, 43, and 50 kDa. Subsequent immunoblotting with anti‐cytokeratin antibodies detected two urea‐soluble, SDS‐insoluble proteins with apparent molecular masses of 45 and 66 kDa. The 45‐kDa protein was identified as cytokeratin 19. An antibody reacting with a palette of cytokeratins (CK 1–18 and CK 20), KL1, was the only antibody that reacted with the 66‐kDa polypeptide. We conclude that sperm ODF fractions contain at least one each of type I and type II intermediate filaments. As keratins and intermediate filaments are described as rope‐like structures, we suggest that these intermediate filaments play an important structural or tension‐bearing role in sperm flagella.  相似文献   
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The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.  相似文献   
4.
Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.  相似文献   
5.
Quinclorac (3,7-dichloro-8-quinolinecarboxylic acid) is a new herbicide in United States rice production. Field studies were conducted in 1990 and 1991 in Mississippi to determine the influence of application timings and rates on weed control efficacy and rice yield. Control of Echinochloa crus-galli (L.) Beauv. (barnyard-grass), Sesbania exaltata (Raf.) Rydb. ex A. W. Hill (hemp sesbania) and Ipomoea wrightii Gray (palmleaf morning glory) were greatest with early post-emergence application. Efficacy of pre-emergence application depends strongly on soil moisture, with significantly reduced weed control resulting when applied to dry soil. Weed control with pre-emergence application to moist soil was comparable with early post-emergence application at higher rates of quinclorac. Pre-plant and incorporated quinclorac controlled weeds effectively. Control of E. crus-galli, S. exaltata and I. wrightii ranged from 73 to 99%, 75 to 99%, and 92 to 99% at 28 days after treatment, respectively. Rice yield generally reflected weed control. No rice injury was observed for any treatment. Results indicate that early post-emergence application of quinclorac is the best time for using reduced rates and field conditions at application should be considered with these rates pre-emergence.  相似文献   
6.
A total of 474 pregnancy tests (of all three types) were carried out on 82 bitches of a variety of breeds. The practical problems and possible sources of error for each test were studied and their accuracy in predicting whether or not the bitches would whelp was ascertained. Palpation of the abdomen, in the period from 26 to 35 days after mating, was found to be 87% accurate in detecting bitches that would whelp and 73% accurate in detecting bitches that would not whelp. The optimum period for using A-mode ultrasound was found to be from 32 to 62 days after mating. In this period the accuracy of detecting bitiches that would whelp was 90%, and for non-whelping bitches was 83%. Two Doppler ultrasound instruments were used. For the superior instrument, the accuracy of detecting whelping bitches was 85% and 100%, in the periods from 36 to 42 days and 43 days to term, respectively. For detection of non-whelping bitches, the accuracy was 100%.  相似文献   
7.
含莫纳可林K红曲降低鸡蛋胆固醇效果的研究   总被引:1,自引:0,他引:1  
48只68周龄的海兰褐蛋鸡分成三组,按0.5%和10%比例分别添加含0.4%莫纳可林K红曲于各组日粮内,饲喂22d,观测其对鸡蛋胆固醇变化的影响。结果表明,投药后5—6d,10%添加组和5%添加组蛋黄胆固醇开始下降;15—22d的胆固醇含量与1~5d相比,10%添加组和5%添加组分别下降了9.02%和5.10%,而对照组升高了5.22%。  相似文献   
8.
Milk fever and calcium metabolism   总被引:1,自引:0,他引:1  
Allen, W.M. & Sansoni, B.F. Milk lever and calcium metabolism. J. vet. Pharmacol. Therap. 8, 19–29.
W.M. Allen, Department of Functional Pathology, AFRC Institute for Research on Animal Diseases, Campion, Newbury, Berkshire RC16 ONN, England.  相似文献   
9.
A method is described for investigating radiographically the shape of the bitch's vagina. The intra-pelvic vagina is readily dilated whereas the intra-abdominal vagina is narrow and tortuous, and cranially is typically ‘spoon-shaped’. Contrast medium entered the uterus during pro-oestrus, oestrus and the post-partum period, indicating patency of the cervix at these times. No cervical relaxation was evident at the end of the luteal phase, i.e. during anoestrus. The possible relevance of these findings to the aetiology of pyometra is discussed.  相似文献   
10.
The relationship between in vitro erythrocyte 75Se uptake (75Se uptake) and erythrocyte glutathione peroxidase (EGSHPx) activity was examined in weaner sheep during periods of selenium depletion and repletion, to determine whether 75Se uptake was better correlated than EGSHPx activity to the development of weaner nutritional myopathy. In the 2 trials conducted, only 3 of 45 Merino wether weaners developed clinical myopathy and histological lesions in skeletal muscles. The 75Se uptake values and EGSHPx activities in these 3 sheep were no different from those in the unaffected sheep. There was a significant negative correlation between 75Se uptake values and EGSHPx activities over the entire period of the trials. It could not be demonstrated that 75Se uptake was any better correlated than EGSHPx activity to the development of nutritional myopathy, and it was concluded that EGSHPx activity indicated selenium status better than 75Se uptake in weaner sheep.  相似文献   
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