Development of an enzyme-linked immunosorbent assay (ELISA) for vitellogenin measurement in greenback flounder Rhombosolea tapirina     

B. Sun  N.W. Pankhurst  M. Watts 《Fish physiology and biochemistry》2003,29(1):13-21

Vitellogenin (Vtg) was purified from the plasma of 17-estradiol (E₂)-injected male greenback flounder,Rhombosolea tapirina. The molecular weight of the native Vtg was estimated by gel filtration as 540 kD. SDS-PAGE and Western blotting analyses indicated that this protein consisted of three bands with molecular weights of 155, 104, 79 kD, respectively. A polyclonal antibody against the highest molecular weight band of putative Vtg was generated in sheep and an indirect antibody-capture competitive enzyme-linked immunosorbent assay (ELISA) was developed. The assay was validatedfor plasma Vtg measurement in greenback flounder. Serial dilutions of plasma from vitellogenic females parallelled the standard Vtg curve, whereas no cross-reaction was observed with the plasma of males in the ELISA. The Vtg ELISA was used to assess the induction of Vtg by E₂ in vivo in males. The induction of Vtg in greenback flounder showed a time- and dose-dependent response as in other species. In E₂-treated fish, detectable levels of Vtg were first found at 48 h, and reached a peak at 96 h post-injection. Plasma levels of Vtg increased as the E2 dose increased with a threshold of 0.1 mg kg^–1.  相似文献   

Effects of dbcAMP on steroidogenesis in isolated ovarian follicles of Atlantic salmon     

M. Watts  N.W. Pankhurst  H. King 《Fish physiology and biochemistry》2003,28(1-4):375-376

In vitro estradiol-17β (E₂) and testosterone (T) production were measured in vitellogenic follicles of Atlantic salmon in response to treatment with human chorionic gonadotropin (hCG) and 2-0-dibutyryladenosine 3′,5′-cyclic monophosphate (dbcAMP). DbcAMP stimulated T production but had no effect on E₂, whereas hCG treatment stimulated E₂ production but T production was low. Elevated intracellular [cAMP] may be part of the normal mechanism for inhibition of aromatase activity at the end of vitellogenesis.  相似文献   

Efficacy of a cold-adapted, intranasal, equine influenza vaccine: challenge trials.     

H G Townsend  S J Penner  T C Watts  A Cook  J Bogdan  D M Haines  S Griffin  T Chambers  R E Holland  P Whitaker-Dowling  J S Youngner  R W Sebring 《Equine veterinary journal》2001,33(7):637-643

A randomised, controlled, double-blind, influenza virus, aerosol challenge of horses was undertaken to determine the efficacy of a cold-adapted, temperature sensitive, modified-live virus, intranasal, equine influenza vaccine. Ninety 11-month-old influenza-na?ve foals were assigned randomly to 3 groups (20 vaccinates and 10 controls per group) and challenged 5 weeks, 6 and 12 months after a single vaccination. Challenges were performed on Day 0 in a plastic-lined chamber. Between Days 1 and 10, animals were examined daily for evidence of clinical signs of influenza. Nasal swabs for virus isolation were obtained on Day 1 and Days 1 to 8 and blood samples for serology were collected on Days 1, 7 and 14. There was no adverse response to vaccination in any animal. Following challenge at 5 weeks and 6 months, vaccinates had significantly lower clinical scores (P = 0.0001 and 0.005, respectively), experienced smaller increases in rectal temperature (P = 0.0008 and 0.0007, respectively) and shed less virus (P<0.0001 and P = 0.03, respectively) over fewer days (P<0.0001 and P = 0.002, respectively) than did the controls. After the 12 month challenge, rectal temperatures (P = 0.006) as well as the duration (P = 0.03) and concentration of virus shed (P = 0.04) were significantly reduced among vaccinated animals. The results of this study showed that 6 months after a single dose of vaccine the duration and severity of clinical signs were markedly reduced amongst vaccinated animals exposed to a severe live-virus challenge. Appropriate use of this vaccine should lead to a marked reduction in the frequency, severity and duration of outbreaks of equine influenza in North America.  相似文献   

Stereodependent bioactivation of R(+)-ethyl S-propyl methylphosphonothioate: Is the S-oxide the active metabolite?     

M.C. French  C.R. Hall  J.M. Harrison  T.D. Inch  D.J. Sellers  A.P. Smith  D.G. Upshall  P. Watts 《Pesticide biochemistry and physiology》1985,24(1):53-60

R(+)-Ethyl S-propyl methylphosphonothioate is bioactivated both in vivo and when perfused through isolated liver to give a product which is much more active as an inhibitor of acetylcholinesterase than the parent compound. The bioactivation does not occur in hepatectomised animals. Acetylcholinesterase inhibited by the active metabolite is not reactivated by pyridine-2-aldoxime methanesulphonate (P2S), whereas enzyme inhibited by the parent compound and its S(?) enantiomer is reactivatable. Attempts to identify the active metabolite were unsuccessful and experiments to explore its stability were inconclusive. Extensive in vitro studies of the inhibition of acetylcholinesterase by the enantiomers of ethyl S-propyl methylphosphonothioate and ethyl S-diisopropylaminoethyl methylphosphonothioates and subsequent reactivation of the enzyme by P2S showed that (a) there are large differences between the rates of inhibition of the R and S enantiomers of both compounds, (b) reactivation profiles are critically dependent on reaction conditions, and (c) the reactivation profiles of the R and S enantiomers of the former compound are indistinguishable under all conditions whereas differences are observed under some conditions for the latter pair of enantiomers. The results are discussed in terms of the possibility that the S-oxide of R(+)-ethyl S-propyl methylphosphonothioate is the active metabolite and it is concluded that this is unlikely.  相似文献   

Isoenzyme and cotyledon protein variation for identification of black beans (Phaseolus vulgaris L.) with similar seed morphology     

D. R. Driedger  B. M. Watts  A. Hussain  L. G. Elias 《Euphytica》1993,74(1-2):27-34

Summary Methods developed to identify genetically diverse varieties of beans (Phaseolus vulgaris L.) were applied to closely related lines that were difficult to distinguish on the basis of seed morphology. Seedling tissues and seeds of black beans, were examined electrophoretically for isoenzyme and cotyledon proteinn protein patterns. Seven enzymes, extracted from seeds or from seedling stem, root or leaf tissues, were compared for polymorphism. Peptidase, polyphenol oxidase, phosphoglucoisomerase and glutamate oxaloacetate transaminase patterns were the same for all lines. Some differences were observed for acid phosphatase, peroxidase and esterase patterns, but complete discrimination of the six selected lines was not possible on the basis of isoenzyme patterns alone. Using polyacrylamide gel electrophoresis (PAGE) of dissociated 0.1 M acetic acid soluble proteins at pH 3.1 (acid-PAGE), or sodium dodecyl sulphate PAGE (SDS-PAGE) of residual protein extracts, all but one pair of samples in each case could be distinguished from the other samples. Using both techniques all of the lines could be identified unequivocally.  相似文献   

Adverse effects of simulated harvesting of short-rotation willow and poplar coppice on vertical pressures and rut depths     

C.W. Watts  L.J. Clark  W.C.T. Chamen  A.P. Whitmore 《Soil & Tillage Research》2005,84(2):192-199

Little is known of the effects of mechanized harvesting on ground conditions during the harvesting of short-rotation coppice. An investigation was therefore carried out in which different vehicles were used to simulate the effects of wheeling from heavy and light harvesters and crop removal equipment. The experiments were carried out on sites containing Bowles hybrid willow (Salix viminalis) and poplars (Populas rap) and on clay and sandy loam soils. The effect of different vehicles was assessed in terms of rut damage and direct measurements of soil stress using buried sensors. Maximum stresses measured 0.3 m below tractor wheels ranged from 50 to 200 kPa, but the greatest stresses, 350 kPa, were recorded under laden trailer wheels. Maximum stresses measured beneath crawler tracks were only 25 kPa. Similarly, substantial ruts were caused by vehicles simulating wheeled harvesters, the deepest ruts were caused by laden trailers but crawler tracks created least disturbance. Wheeling was carried out at soil water contents above the plastic limit and the deepest ruts were created on clay rather than sandy loam soil. The effects of the stresses generated in the soil could impede future root growth, and the deeper ruts formed could damage existing root systems of coppice.  相似文献   

Analysis of myoglobin derivatives in meat or fish samples using absorption spectrophotometry   总被引：1，自引：0，他引：1  

S K Wolfe  D A Watts  W D Brown 《Journal of agricultural and food chemistry》1978,26(1):217-219

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Estrogenic activity in white and red wine extracts   总被引：8，自引：0，他引：8  

Klinge CM  Risinger KE  Watts MB  Beck V  Eder R  Jungbauer A 《Journal of agricultural and food chemistry》2003,51(7):1850-1857

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Effectiveness of protected areas in north-eastern New South Wales: recent trends in six measures     

R.L PresseyT.W Barrett  M.E Watts 《Biological conservation》2002,106(1):57-69

We applied six measures of effectiveness to recent decisions about additional conservation areas in north-eastern New South Wales. Three have been widely used previously: (1) number of conservation areas; (2) total extent of conservation areas; and (3) representativeness (the proportion of natural features such as forest types or animal species represented in conservation areas to some targeted level). The other measures were: (4) efficiency or representation bias (the extent to which some features are protected above target levels at the expense of others that remain poorly protected); (5) relative protection of vulnerable areas within public land (percentage protection of flat, fertile areas relative to that of steep and/or infertile areas); and (6) relative protection of vulnerable areas across all tenures (the correlation between the amount of protection given to features and their vulnerabilities to clearing). We applied the measures in two chronological comparisons: the reserve system in 1994, 1996 and 1997; and before and after the Interim Assessment Process of 1996 which involved negotiations over new reserves and extensive unreserved areas that were temporarily deferred from logging. Over the study period, despite expansion of formal conservation and progress towards quantitative conservation targets, gazetted reserves remained strongly biased to the steep and/or infertile parts of public lands. Both gazetted reserves and areas deferred from logging increased the bias in protection away from forest types most vulnerable to clearing and for which regional conservation targets had already been most compromised. Two major challenges for future conservation decisions in the region are common to conservation planning generally: (1) to focus protection within public tenure on habitats and species most vulnerable to threatening processes such as logging; and (2) to provide more effective conservation management on private lands where loss of native vegetation continues.  相似文献   

A 50,000-year record of climate oscillations from Florida and its temporal correlation with the heinrich events     

Grimm EC  Jacobson GL  Watts WA  Hansen BC  Maasch KA 《Science (New York, N.Y.)》1993,261(5118):198-200

Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf.  相似文献