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Biomedical subjects

R Ruppanner

Publications and source records attributed to R Ruppanner.

51 records · Page 3Linked to original sources

Toxoplasma antibodies among bobcats and other carnivores of norther California.

The prevalence of antibodies to Toxoplasma gondii was investigated among five species of wild carnivores in Norther Ccalifornia. The highest prevalence was among bobcats (Lynx rufus), with 15 of 21 tested being serologically positive. Other results included serological evidence of toxoplasmosis in two of seven raccoons (Procyon lotor), one of three badgers (taxidea taxus) and two of three coyotes (Canis latrans). Two gray foxes (Urocyon cinereoargenteus) were serologically negative. Oone badger with an indirect hemagglutination antibody titer of 1:8192 was found to harbor T. gondii in its brain tissues.

Animals↗

Equine toxoplasmosis: a survey for antibodies to Toxoplasma gondii in horses.

A nationwide sample of horses was tested to determine the prevalence of toxoplasma antibodies in equine animals. Of 1,294 serum samples from horses tested by the microtitration indirect hemagglutin test, 20% were positive. Among the popular breeds of horses, the following antibody prevalences were found: Arabian, 19%; Paint, 22%; Quarter Horses, 13%; Thoroughbred, 24%; and Standardbred, 17%. The antibody prevalence increased from 2% in horses 1 year of age to 18% in 2-year-olds, and rose to 38% in horses 12 years of age. Significant differences were not evident by broad geographic locations across the United States. However, there were differences in prevalence according to premises where the horses were kept. On some ranches, there was no evidence of infection, whereas up to 67% of the horses on other premises were seropositive for toxoplasmosis.

Age Factors↗

Hydatid disease is endemic in California.

Hydatid disease, a parasitic infection of global importance and a condition for which there is no known medical treatment, is established endemically in the Central Valley of California. Only further study will reveal whether or not the infection is now spreading or intensifying or is remaining fairly stable at a relatively low level of endemicity. California physicians should be aware of its presence and the fact that in most sheep-raising areas of the world it constitutes a problem of major medical and public health importance. Although a number of national or regional programs for hydatid disease control have been undertaken, clear progress has been evident only in Iceland, in New Zealand and in the Australian state of Tasmania.(2,4,5)

Adult↗

Q fever hazards from sheep and goats used in research.

Two recent outbreaks of Q fever in research institutions prompted the authors to review extant data, in an effort to delineate hazards to humans from small ruminants used in research. Prevalence of Q fever antibodies was 24% among 2097 sheep and 57% among 1475 goats from various sources. In a facility using sheep for prenatal research, in which an epidemic of human Q fever later occurred, antibody prevalence among sheep was 77%, with larger than usual proportions of high (greater than or equal to 128) titers. Antibody prevalence was 5% in a sample from the general human population and 11% among 347 persons at three research institutions (17% among students, 8% among the research staff). Except for animal caretakers routinely exposed to sheep, antibody prevalence among research staff approximated prevalence in the general population. Suggestions are made for surveillance and vaccination of sheep and goats used in medical research institutions.

Animals↗

Coronaviruses associated with outbreaks of transmissible enteritis of turkeys in Quebec: hemagglutination properties and cell cultivation.

Coronaviruses were observed by electron microscopy in the intestinal contents of turkeys in Quebec flocks where repeated outbreaks of enteritis occurred. Three isolates could be serially propagated in turkey embryos inoculated by the amniotic route with clarified intestinal contents. Purification and concentration of viral particles contained in intestinal contents of infected embryos were achieved by precipitation with polyethylene glycol and ultracentrifugation on sucrose density gradients. Three particle types were demonstrated: intact virions with a density of 1.18 to 1.20 g/ml and incomplete particles with densities of 1.14 and 1.24 g/ml. Hemagglutination of rabbit and guinea pig erythrocytes was demonstrated with the intact viral particles; the hemagglutinin was not dependent on incubation temperature. All the isolates were antigenically related, as shown by hemagglutination-inhibition. The turkey coronaviruses did not cross-react with antisera against coronaviruses of avian infectious bronchitis, porcine transmissible enteritis, bovine neonatal calf diarrhea, or mouse hepatitis. One of the Quebec isolates was shown to induce syncytia formation on its third passage in primary chicken-embryo kidney cell cultures. Electron-microscopic examination of infected cell-culture fluids revealed characteristics coronavirus particles identical to those found in intestinal contents of infected turkeys.

Animals↗

Enzyme immunoassay of Chlamydia in birds.

Serum samples from 192 free-living birds (27 species) were tested for antibodies against Chlamydia using the enzyme-linked immunosorbent assay (ELISA); 97 (51%) were seropositive. The highest antibody prevalence was among pheasants (96%), ducks (88%), and blackbirds (86%). None of 41 starlings tested were seropositive. The serotesting of 42 confined pheasants indicated 100% exposure to the organism. The ELISA is a sensitive, rapid serologic method that can be of epidemiologic and diagnostic value for detecting exposure to Chlamydia. The ELISA could also be used for mass-screening of pet birds where chlamydiosis may be considered a potential public health hazard.

Animals↗

Observation on chemotherapy in cows chronically infected with Coxiella burnetii (Q fever).

Pregnant dairy cows chronically infected with Coxiella burnetii were treated orally with 8 mg of chlortetracycline per kilo of body weight each day for 30 days during their dry period. With the exception of a sample of mammary fluid collected at 28 days, rickettsiae were not recovered from the mammary fluids after the second week of treatment. In addition, the organism was not recovered by mouse inoculation from placental tissues, colostrum or calf tissues that were examined after parturition. Results of oral chemotherapy studies in cows and guinea-pigs suggest that in some cases chlortetracycline may suppress rather than eradicate the Q fever agent.

Animals↗