Bovine TB and the development of new vaccines     

Hope JC  Villarreal-Ramos B 《Comparative immunology, microbiology and infectious diseases》2008,31(2-3):77-100

Bovine tuberculosis (bTB) is caused by Mycobacterium bovis. The incidence of bTB is increasing in cattle herds of developed countries that have a wild life reservoir of M. bovis, such as the UK, New Zealand and the USA. The increase in the incidence of bTB is thought to be due, at least in part, to a wildlife reservoir of M. bovis. M. bovis is also capable of infecting humans and on a worldwide basis, M. bovis is thought to account for up to 10% of cases of human TB [Cosivi O, Grange JM, Daborn CJ et al. Zoonotic tuberculosis due to Mycobacterium bovis in developing countries. Emerg Infect Dis 1998;4(1):59–70]. Thus, the increased incidence of bTB, besides being a major economic problem, poses an increased risk to human health. In the UK, the incidence of bTB continues to rise despite the use of the tuberculin test and slaughter control policy, highlighting the need for improved control strategies. Vaccination of cattle, in combination with more specific and sensitive diagnostic tests, is suggested as the most effective strategy for bovine TB control. The only vaccine currently available for human and bovine TB is the live attenuated Bacille Calmette Guerin (BCG). BCG is thought to confer protection through the induction of Th1 responses against mycobacteria. However, protection against TB conferred by BCG is variable and to this date the reasons for the successes and failures of BCG are not clear. Therefore, there is a need to develop vaccines that confer greater and more consistent protection against bTB than that afforded by BCG. Given that BCG is currently the only licensed vaccine against human TB, it is likely that any new vaccine or vaccination strategy will be based around BCG. In this review we discuss immune responses elicited by mycobacteria in cattle and the novel approaches emerging for the control of bovine TB based on our increasing knowledge of protective immune responses.  相似文献   

Isotopic compositions of cometary matter returned by Stardust     

McKeegan KD  Aléon J  Bradley J  Brownlee D  Busemann H  Butterworth A  Chaussidon M  Fallon S  Floss C  Gilmour J  Gounelle M  Graham G  Guan Y  Heck PR  Hoppe P  Hutcheon ID  Huth J  Ishii H  Ito M  Jacobsen SB  Kearsley A  Leshin LA  Liu MC  Lyon I  Marhas K  Marty B  Matrajt G  Meibom A  Messenger S  Mostefaoui S  Mukhopadhyay S  Nakamura-Messenger K  Nittler L  Palma R  Pepin RO  Papanastassiou DA  Robert F  Schlutter D  Snead CJ  Stadermann FJ  Stroud R  Tsou P  Westphal A  Young ED  Ziegler K  Zimmermann L  Zinner E 《Science (New York, N.Y.)》2006,314(5806):1724-1728

Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single (17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is (16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.  相似文献   

The effect of intra-articular mepivacaine administration prior to carpal arthroscopy on anesthesia management and recovery characteristics in horses     

Angela M. Gaesser DVM  Kelley M. Varner DVM  Hope F. Douglas VMD  DACVS  Ciara A. Barr VMD  DACVAA  Klaus Hopster DMV  PhD  DECVAA  David G. Levine DVM  DACVS  DACVSMR 《Veterinary surgery : VS》2020,49(7):1343-1349

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Activity,origins and location of cellulases in a silt loam soil     

C. F. A. Hope  R. G. Burns 《Biology and Fertility of Soils》1987,5(2):164-170

Summary Cellulase activity in a silt loam soil was assayed and characterised using a microcrystalline cellulose substrate (Avicel). Activity was maximal between pH 5.3 and pH 6.0. A 64% loss in activity was observed on air-drying the soil. However, the residual activity was stable to storage at 40°C for 7 days and was resistant to the action of added protease. The component endoglucanase and -D-glucosidase activities in field-moist and air-dried soil were also assayed. The proportion of the soil microbial population able to utilise cellulose was investigated and the persistence of two free (soluble) cellulase preparations of microbial origin was determined following their addition to soil. A rapid decline in the endoglucanase activity of a Streptomyces sp. cellulase preparation was observed while 30% of the original activity of a Trichoderma viride cellulase preparation could still be detected after 20 days. From the data obtained in this study it appears that the major portion of the -D-glucosidase activity is bound to and protected by the soil colloids. By contrast, the major portion of the exo- and endoglucanase activity appears to be free in the soil solution, attached to the outer surfaces of cellulolytic microorganisms or associated in enzyme substrate complexes. The low residual activity measured in air-dried soil may owe its stability to an association with soil colloids or with recalcitrant cellulosic material present in soil.  相似文献   

Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets     

Ishii HA  Bradley JP  Dai ZR  Chi M  Kearsley AT  Burchell MJ  Browning ND  Molster F 《Science (New York, N.Y.)》2008,319(5862):447-450

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.  相似文献   

The effect of harvest date and rate of nitrogen fertilization on the maturity,yield and chipping quality of potatoes     

G. W. Hope  D. C. MacKay  L. R. Townsend 《American Journal of Potato Research》1960,37(1):28-33

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Modelling the effects of forest landscape dynamics on focal species in Glen Affric, northern Scotland     

Hope  Joseph C.E.; Humphrey  Jonathan W.; Stone  Duncan 《Forestry》2006,79(3):293-302

Current conservation policies promote expansion of semi-naturalwoodland in order to offset effects of past loss and fragmentation.However, conflicts of interest may occur when such expansionwould be at the expense of open habitats considered to haveconservation value in their own right. Landscape modelling ispresented as a method that may prove useful in resolving complexland use issues such as this. An example is given of a modellingsystem that uses forest dynamics modelling, focal species andhabitat network analysis to address landscape change issuesin Glen Affric, a key area for biodiversity conservation innorthern Scotland. The results suggest that a dispersed patternof woodland expansion may offer the best chances of achievinga balance between woodland and open ground in a single catchment.However, there are high levels of uncertainty associated withboth model input data and some of the ecological assumptionswithin the modelling process. Landscape modelling is an emergingdiscipline, and further work is needed to enhance confidencein model outputs.  相似文献   

Specificity of four serologic assays for Mycobacterium avium ss paratuberculosis in llamas and alpacas: a single herd study.     

D S Miller  M T Collins  B B Smith  P R Anderson  J Kramsky  G Wilder  A Hope 《Journal of veterinary diagnostic investigation》2000,12(4):345-353

An investigation was conducted for Mycobacterium avium ss paratuberculosis infections in a research herd of llamas and alpacas. Herd culture-negative status was established over a 23-month period by screening any individuals with any signs compatible with paratuberculosis (n = 1), high serology values (n = 8), or other health and research related reasons (n = 24). There were no M. avium ss paratuberculosis isolates from radiometric cultures of multiple tissue and fecal samples from these individuals and no known sources of exposure. Paratuberculosis is uncommon in North American llamas and alpacas: only 5 cases were identified after an extensive search of the Veterinary Medical Data Base, diagnostic laboratory records, publication databases, and personal communications. Therefore, serum samples from llamas (n = 84) and alpacas (n = 16) in the culture-negative herd were used to obtain preliminary estimates of test specificity for 3 enzyme-linked immunoassays (ELISAs) and an agar gel immunodiffusion (AGID) assay kit for detecting serum antibodies to M. avium ss paratuberculosis in South American camelids. The ELISAs were modifications of established bovine assays for antibody detection. With provisional cutoffs, ELISA-A had 52 false positives (specificity 48%), ELISA-B had 8 false positives (specificity 92%), ELISA-C had two false positives (specificity 98%), and the AGID had 0 false positives (specificity 100%). The range of ELISA values for culture-positive llamas and alpacas (n = 10) from other herds overlapped the range of values for culture-negative llamas and alpacas. The accuracy of the ELISAs may be improved by using age- and sex-specific cutoffs because uninfected male llamas and alpacas that were older than 1 year had higher values for some tests. These tests can be used for either llamas or alpacas; the protein-G conjugate ELISA (ELISA-B) may be useful for multispecies applications. These assays are best used for rapid presumptive diagnoses of llamas and alpacas with diarrhea and weight loss and as a screening tool for herds known to be exposed to infection. All seropositive results should be confirmed with culture.  相似文献   

Toxicosis in horses after ingestion of hoary alyssum.   总被引：1，自引：0，他引：1  

R J Geor  R L Becker  E W Kanara  L R Hovda  W H Sweeney  T F Winter  J K Rorick  G R Ruth  E Hope  M J Murphy 《Journal of the American Veterinary Medical Association》1992,201(1):63-67

Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.  相似文献   

Size and shape of the lateral intercellular spaces in a living epithelium   总被引：7，自引：0，他引：7  

K R Spring  A Hope 《Science (New York, N.Y.)》1978,200(4337):54-58

The lateral intercellular spaces of Necturus gallbladder epithelium were seen and measured while the living tissue was perfused in a new chamber. The compliance of the lateral cell membranes was calculated from the measured pressure-volume characteristics of the lateral intercellular spaces.  相似文献