Ivermectin: a potent new antiparasitic agent   总被引：22，自引：0，他引：22  

W C Campbell  M H Fisher  E O Stapley  G Albers-Sch?nberg  T A Jacob 《Science (New York, N.Y.)》1983,221(4613):823-828

Ivermectin is the 22,23-dihydro derivative of avermectin B1, a macrocyclic lactone produced by an actinomycete, Streptomyces avermitilis. It is active at extremely low dosage against a wide variety of nematode and arthropod parasites, apparently by virtue of its action on the mediation of neurotransmission by gamma-aminobutyric acid. It is now in commercial use in various countries for the treatment and control of parasites in cattle, horses, and sheep, and is expected to become available for use in swine and dogs. Since studies with the drug in man are in a preliminary stage, it is not yet known whether ivermectin will be useful in human medicine.  相似文献   

Tissue, developmental, and tumor-specific expression of divergent transcripts in Wilms tumor   总被引：17，自引：0，他引：17  

A Huang  C E Campbell  L Bonetta  M S McAndrews-Hill  S Chilton-MacNeill  M J Coppes  D J Law  A P Feinberg  H Yeger  B R Williams 《Science (New York, N.Y.)》1990,250(4983):991-994

  相似文献   

Conviction seeking efficacy: Sustainable agriculture and the politics of co-optation     

David Campbell 《Agriculture and Human Values》2001,18(4):353-363

Proponents of sustainable agriculture seek deeply rooted social changes, but to advance this agenda requires political credibility and work with diverse partners. Asthe literature on political co-optation makesclear, the tension between conviction andcredibility is persistent and unavoidable; nota problem to be solved so much as a built-incondition of movement politics. Drawing on acase history of California's largestsustainable agriculture organization, astructural assessment is made of the strategicchoices facing movement leaders, organizationaltensions that accompany these choices, andperceived gains and losses. The case historydemonstrates how movement leaders craft middlerange strategies that adapt to politicalcircumstances while retaining attachments tocore values and constituencies. Thesestrategies are ripe with tradeoffs, placingdemands on leaders who must implement them in aspirit that sustains organizational vitalitywhile broadening political and social impact.But they also enlarge the democraticsensibilities of movement leaders, increasingtheir ability to listen, learn, and forgealliances based on shared goals rather thansimilar motives.  相似文献   

Reconstitution of DNA segregation driven by assembly of a prokaryotic actin homolog     

Garner EC  Campbell CS  Weibel DB  Mullins RD 《Science (New York, N.Y.)》2007,315(5816):1270-1274

Multiple unrelated polymer systems have evolved to partition DNA molecules between daughter cells at division. To better understand polymer-driven DNA segregation, we reconstituted the three-component segregation system of the R1 plasmid from purified components. We found that the ParR/parC complex can construct a simple bipolar spindle by binding the ends of ParM filaments, inhibiting dynamic instability, and acting as a ratchet permitting incorporation of new monomers and riding on the elongating filament ends. Under steady-state conditions, the dynamic instability of unattached ParM filaments provides the energy required to drive DNA segregation.  相似文献   

The genome sequence of Trypanosoma cruzi, etiologic agent of Chagas disease     

El-Sayed NM  Myler PJ  Bartholomeu DC  Nilsson D  Aggarwal G  Tran AN  Ghedin E  Worthey EA  Delcher AL  Blandin G  Westenberger SJ  Caler E  Cerqueira GC  Branche C  Haas B  Anupama A  Arner E  Aslund L  Attipoe P  Bontempi E  Bringaud F  Burton P  Cadag E  Campbell DA  Carrington M  Crabtree J  Darban H  da Silveira JF  de Jong P  Edwards K  Englund PT  Fazelina G  Feldblyum T  Ferella M  Frasch AC  Gull K  Horn D  Hou L  Huang Y  Kindlund E  Klingbeil M  Kluge S  Koo H  Lacerda D  Levin MJ  Lorenzi H  Louie T  Machado CR  McCulloch R 《Science (New York, N.Y.)》2005,309(5733):409-415

Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention.  相似文献   

Characterization of a Unique “Super Soft” Kernel Trait in Wheat     

Craig F. Morris  James A. Anderson  G. E. King  Arthur D. Bettge  Kimberly Garland‐Campbell  R. E. Allan  E. Patrick Fuerst  Brian S. Beecher 《Cereal Chemistry》2011,88(6):576-583

Kernel texture in wheat (Triticum sp.) is central to end‐use quality and utilization. Here we report the discovery of a novel soft kernel trait in soft white winter wheat (T. aestivum L.). Two heritable kernel phenotypes were selected among F₃‐derived sibs, hereafter designated “normal soft” (wild‐type) and “super soft.” Normal soft lines exhibited single kernel characterization system (SKCS) hardness index (HI) values typical of soft wheat (HI ≈ 20), whereas the super soft lines were unusually soft (HI ≈ 5). Under some environments, individual super soft lines exhibited HI values as low as HI = –4. The super soft trait was manifested in reduced SKCS kernel texture and higher break flour yields, with some increase in sodium carbonate SRC (solvent retention capacity) values and sponge cake volumes. Straight‐grade flour yield, flour ash, milling score, and cookie diameter were largely unaffected. With the possible exception of the sodium carbonate SRC values, we observed no indication that the super soft trait conferred any negative aspects to commercial soft wheat quality. As such, the super soft trait may provide wheat breeders with new opportunities to modify the end‐use quality of wheat.  相似文献   

Use of a point-of-care urine drug test in a dog to assist in diagnosing barbiturate toxicosis secondary to ingestion of a euthanized carcass     

Vicki L. Campbell  DVM  DACVA  DACVECC  ; Amy L. Butler  DVM  MS  DACVECC    Katharine F. Lunn  BMVS  MS  PhD  MRCVS  DACVIM 《Journal of Veterinary Emergency and Critical Care》2009,19(3):286-291

Objective – To describe a case of barbiturate toxicosis in a dog secondary to ingestion of a previously buried euthanized goat carcass and to discuss the utility of urine drug testing in diagnosing barbiturate toxicosis.
Case Summary – A 6-year-old neutered male Border Collie was presented to a university veterinary teaching hospital for evaluation of ataxia and acute collapse. Past pertinent history included Addison's disease that had been managed for 1 year. A companion dog was seen 12 hours earlier chewing on the partially decomposed head of a goat that had been euthanized 47 days previously and buried on the owner's property. The dog was laterally recumbent, unresponsive to stimuli, and hypothermic on physical examination. Initial blood work revealed hyponatremia and hyperkalemia, with a Na/K ratio of 18.5. The dog was volume resuscitated and received an injection of dexamethasone sodium phosphate due to a suspected Addisonian crisis. Despite this treatment, the dog remained laterally recumbent and unresponsive to stimuli. A urine drug screen was performed and was positive for barbiturates. A diagnosis of barbiturate toxicosis secondary to ingestion of a euthanized goat carcass was made. The dog was treated supportively over 12 hours with IV fluids and activated charcoal. The dog was able to walk 11 hours after presentation and was subsequently discharged from the hospital.
New or Unique Information Provided – Urine drug testing is a fast, easy, and point-of-care test that may be useful in dogs to assist in the diagnosis of barbiturate intoxication. Proper disposal of euthanized animals is necessary to prevent toxicosis and possible death of companion animals and wildlife.  相似文献   

Risk factors for post-weaning mortality of Merino sheep in south-eastern Australia   总被引：1，自引：1，他引：0  

AJD Campbell  AL Vizard  JWA Larsen 《Australian veterinary journal》2009,87(8):305-312

Objective   To measure associations between body weight, growth rate, sex, time of shearing and post-weaning mortality of Merino sheep.
Design   Uni- and multivariable survival analyses of sheep mortality during the first year after weaning, using records (n = 3657) from two field experiments conducted in Western Victoria from 1996 to 2003.
Results   Overall mortality was 14.3% (range 4.5–26.8%) and mean maximum mortality rate was 29 deaths/1000 weaners/month. Increased mortality risk was associated with decreases in fleece-free body weight and mean weaner growth rate, particularly at low weights and growth rates. Weaners in the lightest weaning weight quintile had a hazard ratio of 3.5, compared with the middle quintile. The hazard ratio for a 2-kg decrease in weaning weight was 1.2 to 1.7 for weaners lighter than 22 kg. The hazard ratio for a reduction in mean weaner growth rate in the first 5 months after weaning of 0.25 kg/month was 1.1 to 6.8 if mean growth rate was less than 1 kg/month, but did not differ significantly from 1 at greater growth rates. The hazard ratio for wether weaners was approximately 1.5 compared with ewe weaners. The hazard ratio for weaners shorn between December and May, compared with unshorn weaners, was 1.2 to 3.5, with the greatest risk difference associated with shearing in March (45 deaths/1000 weaners/month).
Conclusion   Improving the body weight and mean growth rate of weaner sheep is likely to reduce post-weaning mortality. Lightweight weaners in a flock should be managed separately from the main portion after weaning. In southern Australia, not shearing spring-born Merino weaners between December and May may assist in reducing overall post-weaning mortality.  相似文献   

Blood Lactate Concentrations in Anesthetized Dogs with Intracranial Disease     

L. A. Sullivan  V. L. Campbell  L. S. Klopp  S. Rao 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(3):488-492

Background: The importance of blood lactate concentrations in dogs with intracranial disease has not been established, despite frequently observed hyperlactatemia in dogs undergoing general anesthesia for advanced imaging, surgery, or both.
Hypothesis: Blood lactate concentrations are elevated in anesthetized dogs with intracranial disease, compared with dogs with intervertebral disc disease (IVDD).
Animals: Eighty-five hospitalized dogs undergoing advanced imaging, surgery, or both for primary neurologic disease; 30 with intracranial disease; 55 with IVDD.
Methods: Retrospective study. Age, breed, neurologic diagnosis, time from anesthesia induction to measurement of blood lactate, blood lactate concentration under anesthesia, and concurrently measured heart rate, mean arterial pressure, PCV, arterial hemoglobin oxygen saturation, and arterial partial pressure of oxygen were included in a multivariable linear regression analysis.
Results: Dogs with meningioma (adjusted mean lactate 2.99 mmol/L, 95% CL 2.21–4.05, P < 0.0001) and hydrocephalus (adjusted mean lactate 1.5 mmol/L, 95% CL 0.99–2.27, P = 0.003) had higher blood lactate concentrations compared with dogs with IVDD (adjusted mean lactate 0.79 mmol/L, 95% CL 0.6–1.04). Only dogs with meningioma had clinically important hyperlactatemia (>2.5 mmol/L).
Conclusions: Prospective studies are warranted to determine the degree and clinical importance of high blood lactate concentrations in dogs with intracranial disease.  相似文献   

Differential Tolerances of Amaranthus Strains to High Levels of Aluminum and Manganese in Acid Soils     

C. D. Foy  T. A. Campbell 《Journal of plant nutrition》2013,36(9):1365-1388

Species of Amaranthus are grown extensively as leafy green vegetables in tropical Africa and Asia and as high yielding grain crops in Western South America, Central America, Northern India, Western Nepal, and Pakistan. The crop is often grown on acid, marginal soils, under subsistence conditions, where liming even the soil plow layer may not be economically feasible. Hence, the identification or development of strains with high tolerance to acid soils would be beneficial. Aluminum and Mn toxicities are the most important growth‐limiting factors in many acid soils. The objective of our research was to determine the tolerances of selected Amaranthus strains to high levels of these elements in acid soils.

Fifteen strains, representing five species, were grown in greenhouse pots of an acid, Al‐toxic Tatum soil limed to pH 4.8 and 5.8. Strains differed significantly in tolerance to the acid soil. Relative yields (pH 4.8/pH 5.8%) ranged from 50.1 to 6.3% for tops and from 54.5 to 5.7% for roots. Four strains of A. tricolor L. (vegetable type) were significantly more tolerant than six strains of A. cruentus L. (seed and vegetable type). Strains of A. hypochondriacus L. and A. caudatus L. studied were intermediate in tolerance.

Twelve strains, representing four species, were grown on an acid, Mn‐toxic Zanesville soil at pH 4.6 and 6.3. Strains also differed significantly in tolerance to this acid soil; however, overall growth was better and strain differences were smaller than on Al‐toxic Tatum soil at pH 4.8. On Zanesville soil the relative top yields (pH 4.6/pH 6.3%) ranged from 74.1 to 18.6%. The most tolerant group included three strains of A. tricolor and one strain of A. hypochondriacus, but four strains of A. cruentus were also fairly tolerant. The sensitive end of the scale included one strain of A. cruentus and two strains of A. hypochondriacus.

In general, strains that were most tolerant to the Al‐toxic Tatum soil were also among the most tolerant to the Mn‐toxic Zanesville soil. Likewise, those most sensitive to the high Al soil were most sensitive to the high Mn soil. But some strains that were sensitive to excess Al in Tatum soil were fairly tolerant to high Mn in Zanesville soil.

Results suggest that superior strains of Amaranthus can be selected or developed for use on acid soils.  相似文献