Merogony and gametogony of Eimeria mccordocki (Protozoa-Eimeriidae) in the mule deer, Odocoileus h. hemionus     

B Abbas  G Post  W C Marquardt 《Veterinary parasitology》1987,24(1-2):1-5

Eimeria mccordocki and E. madisonensis oocysts were isolated from feces of 21 of 40 captive mule deer in Fort Collins, Colorado. The two species were separated from each other by infecting one mule deer fawn, and the life cycle of E. mccordocki was studied for the first time. Four to six-weeks-old mule deer fawns were inoculated orally with E. mccordocki and killed 9, 13 and 15 days after infection. Asexual and sexual stages of life cycle developed in the ileum of mule deer, only in the surface epithelial cells of the villi. The asexual stages consisted of two generations of meronts.  相似文献   

An indirect enzyme-linked immunosorbent assay (ELISA) for measuring antibodies in chickens infected with infectious bursal disease virus   总被引：3，自引：0，他引：3  

W W Marquardt  R B Johnson  W F Odenwald  B A Schlotthober 《Avian diseases》1980,24(2):375-385

An immuno-enzyme assay for measuring infectious bursal disease antibodies in chickens is described. The test is performed rapidly after coating plates overnight with partially purified antigen prepared in cell culture. Coated plates can be stored for at last 4 months. The chromatographically purified rabbit anti-chicken immunoglobulin-G, conjugated to horseradish peroxidase, was used optimally at a dilution of 1:3,000. It could be stored for at least 10 months without a reduction in titer. The test is safe, highly reproducible, specific, and sensitive. Results can be read visually or by spectrophotometry. Antibodies could be detected as early as 4 days postinfection. Serum titers rose rapidly to high levels, ranging from 1:1,600 to 1:25,600 by one week postinfection. High titers persisted for up to one year. The results of this assay compare favorably with results obtained with the agar-gel precipitin and virus-neutralization tests.  相似文献   

Antibody response to Newcastle disease virus given by two different routes as measured by ELISA and hemagglutination-inhibition test and associated tracheal immunity   总被引：1，自引：0，他引：1  

W W Marquardt  D B Snyder  P K Savage  S K Kadavil  F S Yancey 《Avian diseases》1985,29(1):71-79

The enzyme-linked immunosorbent assay (ELISA) and the conventional hemagglutination-inhibition (HI) test were compared for their ability to measure the primary serological response of chickens inoculated by the intranasal-intraocular (IN-IO) routes with Newcastle disease virus (NDV) and the secondary response after intratracheal (IT) challenge. In addition, these responses were compared with the temporal antibody response of chickens inoculated only once by the IT route. Both tests detected NDV-specific antibody by 7 days postinoculation (PI) in the IN-IO-inoculated group, while ELISA and the HI test detected antibody at 4 and 7 days, respectively, in the IT-inoculated group. Titers measured by each test were parallel in quantifying the antibody response, and titers rose anamnestically in response to secondary IT challenge at 21 days PI. ELISA titers remained high at 42 days PI, but the HI titers began to decline at this time. There was a good agreement (R = 0.94) between the results of the two tests throughout both primary and secondary responses. Conversely, there was little agreement between the results of the two tests after 21 days PI in the absence of secondary challenge. Antibody levels were higher when inoculation was by the primary IT route, and they persisted throughout the experiment (86 days). Ciliary activity served as a measure of tracheal immunity or infection of tracheal epithelium. It was reduced as early as 2 days PI and was nearly or completely absent by 5-6 days PI.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

A rapid method for preparing avian tracheal rings for organ culture     

W W Marquardt  D B Snyder  S K Kadavil 《Avian diseases》1982,26(1):196-199

A simple, rapid method for preparing rings from chicken tracheas is described. Using a polyacrylamide disc gel slicer, up to 100 uniform tracheal rings were obtained from two tracheas with a single cut and without injury to the ciliated tracheal epithelium. The responses of rings cut with a disc gel slicer and those cut conventionally with a scalpel blade were compared by virus titration, virus neutralization, and viability of uninfected 18-day-old-chick embryo rings over a nine-day incubation period. Rings cut with a disc gel slicer did not differ significantly from those cut conventionally with respect to virus titer, neutralization indices, or viability. A disc gel slicer expedites the preparation of functional rings and offers an alternative to the present method of cutting tracheal rings with a scalpel blade.  相似文献   

Forstschule deutscher Internierter in Schlo? Hard (Ermatingen)     

Marquardt 《Forstwissenschaftliches Centralblatt》1917,39(6):265-267

Ohne Zusammenfassung  相似文献   

Development of a model ribosomal RNA hybridization assay for the detection of Sarcocystis and other coccidia.   总被引：4，自引：0，他引：4       下载免费PDF全文

A A Gajadhar  W C Marquardt    C D Blair 《Canadian journal of veterinary research》1992,56(3):208-213

Two regions of the primary structure of the small subunit rRNA of Sarcocystis muris bradyzoites were compared with nucleotide sequences of S. gigantea, Toxoplasma gondii, Plasmodium berghei and Mus musculus and used to design genus- and species-specific probes for the detection and identification of coccidia. Total cellular RNA of purified S. muris, S. cruzi, T. gondii and Eimeria nieschulzi and coccidia-infected tissues of mouse, ox, sheep and pig, were assayed using twenty-base oligomers labelled with 32P. Hybridization occurred at temperatures ranging from 21 degrees C to 41 degrees C or 51 degrees C. One probe detected only S. muris and another successfully hybridized to several members of coccidia, including S. muris, S. cruzi, T. gondii and E. nieschulzi. One ng of total cellular RNA was sufficient to yield detectable hybrids in slot blot assays. The excellent sensitivity suggests that rRNA-based probes are capable of detecting individual parasites, and can assay low levels of coccidial infections not detectable by other methods. The results of this study show that it is possible to customize the specificity of rRNA-based probes for diagnostic, epidemiological or taxonomic purposes.  相似文献   

Raoult's Law and the Melting Point Depression in Mesoscopic Systems     

Nimtz G  Marquardt PD  Stauffer D  Weiss W 《Science (New York, N.Y.)》1988,242(4886):1671-1672

Data on the melting point depression in small indium or gold particles and in liquid water held between lipid bilayers indicate that these systems obey Raoult's law, with the surface atoms or molecules acting like solute particles in a dilute solution.  相似文献   

Comparison of ciliary activity and virus recovery from tracheas of chickens and humoral immunity after inoculation with serotypes of avian infectious bronchitis virus     

W W Marquardt  S K Kadavil  D B Snyder 《Avian diseases》1982,26(4):828-834

Cross-protection tests with homologous and heterologous serotypes of infectious bronchitis virus (IBV) were used to compare ciliary activity and virus recovery from tracheas of chickens. Validation of this technique included correlating the neutralization indices of antiserum obtained from some infected birds. Chickens were inoculated intratracheally with either the JMK or Connecticut (Conn) serotype of IBV. Three weeks later, infected and uninfected groups were challenged by the same route with homologous and heterologous virus. The JMK strain provided immunity against homologous challenge and the Conn strain, as indicated by good ciliary activity and lack of challenge virus recovery. The Conn strain provided only homologous protection, as ciliostasis occurred and virus was recovered after challenge with the JMK strain. In each case, antiserum to immunizing virus neutralized only the homologous virus. Controls were uniformly susceptible and lacked neutralizing antibody. A similar experiment with the Ark 99 serotype and a recent isolate (397) of IBV revealed complete cross-protection of the tracheas. Antiserum to each virus neutralized the homologous and heterologous virus in each case in reciprocal tests. The results indicate that these two viruses are closely related. The complete agreement between ciliary activity and virus isolation indicates that ciliary activity is a reliable, objective criterion upon which tracheal immunity can be judged in cross-protection tests.  相似文献   

Identification of different BLV provirus isolates by PCR, RFLPA and DNA sequencing     

Beier D  Blankenstein P  Marquardt O  Kuzmak J 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(7-8):252-256

A first attempt for the investigation of molecular epidemiology of BLV was carried out. PCR amplicons of a part of the env gene of BLV isolated from 309 cattle of different geographical origin were compared with known BLV env sequences. Using RFLPA most of the PCR products can be assigned to the Australian, the Japanese or the Belgian subgroup. A phylogenetic tree resulting from the comparison of the sequences of these env fragments demonstrates the relations and differences between and within the subgroups.  相似文献   

Ciliary activity: a criterion for associating resistance to infectious bronchitis virus infection with ELISA antibody titer     

D B Snyder  W W Marquardt  S K Kadavil 《Avian diseases》1983,27(2):485-490

Vaccination and challenge experiments using infectious bronchitis virus (IBV) were conducted on groups of specific-pathogen-free chickens. Three weeks post-vaccination with one of the four IBV strains used, chickens were challenged with the homologous immunizing strain of IBV. Subsequently, the chickens were sacrificed, their tracheas were examined for ciliostasis, and the specific IBV antibody content of their sera was measured by enzyme-linked immunosorbent assay (ELISA). Results showed that protection was conferred by primary vaccination, as ciliostasis was not observed in tracheas from groups vaccinated and then challenged. No protection was observed in control groups that received only a challenge exposure, and the virus was readily recovered from their tracheas. Homologous protection was present in chickens that had ELISA titers as low as 624 and neutralization indices as low as 2.9, whereas susceptible controls had titers of less than 100 and less than 1.0, respectively.  相似文献