Refine search
Results 1-10 of 280
Preliminary studies of the development of Anaplasma marginale in salivary glands of adult, feeding Dermacentor andersoni ticks.
1988
Kocan K.M. | Wickwire K.B. | Ewing S.A. | Hair J.A. | Barron S.J.
On each day of feeding on susceptible calves, salivary glands obtained from groups of adult ticks that transmitted Anaplasma marginale were examined for A marginale colonies by use of light microscopy and transmission electron microscopy. On day 8 of feeding, salivary glands were examined, using fluorescein-labeled antibody and methyl green-pyronine stain. Use of fluorescein-labeled antibody consistently revealed small numbers of fluorescent foci in salivary gland acinar cells obtained from ticks that had fed for 8 days. Colonies of A marginale were seen by transmission electron microscopy only in salivary gland acini of male ticks; these colonies could not be identified, using light microscopy, in companion 1-micron plastic sections stained with Mallory stain. Methyl green-pyronine stain, used commonly to detect theilerial parasites in tick salivary glands, did not differentiate A marginale from cytoplasmic inclusions normally found in salivary gland acinar cells.
Show more [+] Less [-]Relationship of days in gestation at exposure and development of brucelloses in strain 19-vaccinated heifers.
1988
Crawford R.P. | Adams L.G. | Williams J.D.
Heifers injected with 10(8) (n = 40), 10(9) (n = 39), or 10(10) (n =39) colony-forming units of Brucella abortus strain 19 were conjunctivally exposed to 10(7) colony-forming units of strain 2308 during gestation. At parturition, milk from each quarter of the udder, a piece of placenta, and 2 swab specimens of the uterus from the dam plus a swab specimen of the rectum from each calf were cultured for Brucella. If the calf was dead or died, additional specimens of lung, stomach contents, and a mediastinal lymph node also were cultured. Days in gestation was determined for each heifer, using data from rectal palpation after breeding and crown-rump length and weight of calf at parturition, with the median value used for data analysis. In each vaccine dosage group, the proportion (%) of heifers developing brucellosis increased as days in gestation at exposure increased. Strain 2308 was isolated from 3 (11%) of 26, 16 (25%) of 64, and 18 (64%) of 28 heifers that were grouped as less than 121, 121 to 150, and greater than 150 days in gestation at time of exposure, respectively. Thirty-two (86%) of the 37 infected heifers were less than 260 days in gestation at parturition, and calves were premature. Heifers with premature calves were more likely to be infected, and tissues were more likely to yield multiple isolations of strain 2308, regardless of days in gestation at exposure or of days after exposure to parturition. Days after exposure to premature parturition of infected heifers ranged from 35 to 110.
Show more [+] Less [-]Effect of abraded intramammary device on outcome in lactating cows after challenge exposure with Streptococcus uberis.
1988
Paape M.J. | Schultze W.D. | Cortlett N.J. | Weinland B.T.
Intramammary devices (IMD) were abraded with medium-grade emery cloth or were left smooth. One IMD of each type was inserted into a mammary quarter of each of 5 lactating cows. The remaining 2 quarters served as controls. Quarter foremilk, bucket milk, and stripping milk samples were collected for 3 consecutive days at 2 weeks after IMD insertion, and milk somatic cell counts (SCC) were determined. Milk samples also were collected immmediately after and 0.5, 1,2,4,6,8, and 11 hours after milking. All quarters were challenge exposed with 250 colony-forming units of Streptococcus uberis at 2 months after IMD insertion. Foremilk and stripping milk samples were collected for bacteriologic culture and SCC at the next 10 milkings. Mean foremilk, bucket milk, and stripping milk SCC (X 10(6) cells/ml) were 0.18, 0.07, and 0.91, respectively, for quarters with abraded IMD; 0.06, 0.05, and 0.43, respectively, for quarters with smooth IMD; and 0.03, 0.03, and 0.15, respectively, for control quarters. Mean SCC after milking ( X 10(6) cells/ml) for the various intervals were 0.70, 1.29, 0.70, 0.97, 1.15, 1.17, 0.77, and 0.85 for quarters with abraded IMD; 0.43, 0.62, 0.61, 0.45, 0.64, 0.60, 0.31, and 0.26 for quarters with smooth IMD; and 0.15, 0.24, 0.15, 0.19, 0.15, 0.15, 0.14, and 0.06 for control quarters. After challenge exposure, 2 of 5 of the quarters with abraded IMD, 4 of 5 of the quarters with smooth IMD, and 8 of 9 of control quarters became infected. Results indicated that abraded IMD increased SCC in stripping milk to concentrations that provided 60% protection against challenge exposure with S uberis.
Show more [+] Less [-]Campylobacter jejuni infections in gnotobiotic pigs.
1988
Boosinger T.R. | Powe T.A.
Pharmacokinetics and bioavailability of ceftriaxone administered intravenously and intramuscularly to calves.
1988
Soback S. | Ziv G.
Influence of alterations in heart rate on echocardiographic measurements in the dog.
1988
Jacobs G. | Mahjoob K.
Hymenolepidid and dilepidid cestodes with armed rostellum in shrews, Sorex spp., from Hokkaido, Japan.
1988
Sato H. | Kamiya H. | Ohbayashi M.
Comparative study of leptospiral strains ictero No. 1 and RGA by restriction endonuclease DNA analysis.
1988
Hata K. | Yamaguchi T. | Ono E. | Yanagawa R.
Eructation of gas through the gastroesophageal sphincter before and after gastric fundectomy in dogs.
1988
Strombeck D.R. | Turner W.D. | Harrold D.
Effects of topical application of amitraz on plasma glucose and insulin concentrations in dogs.
1988
Hsu W.H. | Schaffer D.D.