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Biomedical subjects

A W Smith

Publications and source records attributed to A W Smith.

At least 109 records · Page 6Linked to original sources
PubMed1988

Immunogenicity, pathogenicity, and transmissibility of a recombinant vaccinia virus in calves.

Experiments concerned with the immunogenicity, pathogenicity, and transmissibility of a recombinant vaccinia:Sindbis virus were conducted. The WR strain of the recombinant vaccinia:Sindis virus was found to be infective for calves and mildly pathogenic, resulting in local tissue reaction. It was not transmissible to other calves. Also, it was found to be immunogenic when inoculated intradermally into calves, and antibody was produced against the parent vector virus (vaccinia) and the Sindbis antigen. Recombinant virus given IV to calves induced no detectable clinical signs, nor did the calves develop neutralizing antibodies. Furthermore, second-passage lesion material containing up to 10(7) tissue culture infective doses of the recombinant virus failed to induce development of lesions or illness in intradermally inoculated calves, and virus could not be recovered from the inoculation sites. In this series of experiments, this vaccinia recombinant given intradermally was immunogenic, mildly pathogenic at the local injection site only, and was not transmissible to contact animals, thus demonstrating the potential efficacy and safety of the WR strain of vaccinia virus when used as a live vector system in cattle.

Animals↗
PubMed1988

Euthanasia.

Explore the source record for details and available documents.

Animal Welfare↗
PubMed1987

Mortality from meningococcal disease during an epidemic in The Gambia, West Africa.

Mortality from meningococcal disease was determined during an epidemic in a rural area of The Gambia with few medical resources, but where a system of registration of births and deaths had been established before the introduction of a primary health care programme. 33 deaths were recorded among 127 patients, a case mortality rate of 26%. 84% of deaths occurred within the first 24 h of illness and many patients died before they could reach any source of treatment. Previous studies, based on regional statistics or on hospital series, may have underestimated mortality from epidemic meningitis in Africa. Mortality from this infection will be reduced only if treatment can be made readily accessible to patients early in the course of their illness.

Adolescent↗
PubMed1987

Antibodies to marine caliciviruses in the Steller sea lion (Eumetopias jubatus Schreber).

Sera from 145 Steller sea lions (76 adults, three subadults, 37 pups, and 29 fetuses) were tested for neutralizing antibodies to nine marine calicivirus serotypes. Antibodies were found to San Miguel sea lion virus (SMSV) types 1, 5, 6, 7, 8, 10 and 13, and to Tillamook (bovine) calicivirus, but no antibodies were found to the walrus calicivirus. Titers (microtiter neutralization assay) ranged from 1:20 to 1:320, with many positive reactions at the higher dilutions (greater than or equal to 1:80). Antibodies to SMSV's 5 and 10 were most common among animals sampled in Alaskan waters, while antibodies to SMSV-6 were most common among pups from the southern Oregon coast. These data provide evidence that Steller sea lions, like their California sea lion (Zalophus c. californianus Lesson) counterparts, have experienced widespread exposure to multiple serotypes of marine caliciviruses.

Animals↗
PubMed1987

Prevalence and distribution of serum neutralizing antibodies to Tillamook (bovine) calicivirus in selected populations of marine mammals.

Neutralizing antibodies to Tillamook calicivirus (TCV) were found in sera collected from California sea lions (Zalophus c. californianus Lesson) in 1983 and 1984 and in sera collected from Steller sea lions (Eumetopias jubatus Schreber) in 1976 and 1985. The combined prevalence of antibodies for these two species was 10/228 = 4.38%. Titers ranged from 1:20 (five animals), to 1:40 (four animals), to 1:80 (one animal) by standard microtiter neutralization assay. The seropositive pinnipeds were dispersed widely along the margins of the eastern Pacific rim, from the Bering Sea to the Santa Barbara Channel. Antibodies to TCV were not found in sera collected from northern fur seals (Callorhinus ursinus L.), Pacific walruses (Odobenus rosmarus divergens Illiger), seals of the family Phocidae, or several cetacean species. Tillamook calicivirus was isolated originally in 1981 from dairy calves in Oregon; the finding of neutralizing antibodies in two widely distributed species of sea lions suggests the possibility of a marine origin for this agent.

Animals↗
PubMed1987

Serology and virology of the bowhead whale (Balaena mysticetus L.).

Sera from four bowhead whales (Balaena mysticetus L.) were examined for the presence of specific antibodies, and tissue and swab samples from six and four animals respectively were processed for isolation of viruses and for initiation of bowhead whale cell cultures. All sera were negative for antibodies to nine serovars of Leptospira interrogans and to 21 orthomyxovirus subtypes and a paramyxovirus (Newcastle disease virus). All sera were positive, however, for neutralizing antibodies to one or more calicivirus serotypes. Two untyped adenoviruses were isolated from colon samples of two different whales, but neutralizing antibodies to the agents could not be demonstrated in any sera. Three primary bowhead whale cell cultures were derived from kidney (two cultures) and testis (one culture), from three individual whales.

Animals↗
PubMed1987

First isolation of a calicivirus from the Steller sea lion (Eumetopias jubatus).

A calicivirus was isolated from the rectum of a Steller sea lion (Eumetopias jubatus) pup on Rogue Reef, off the southern Oregon coast. Based on the results of neutralization tests with specific typing antisera, the isolate was identified as San Miguel sea lion virus serotype 6 (SMSV-6). Blood obtained from nine of 37 pups (24%) during virus sample collection procedures had specific neutralizing antibodies to SMSV-6. The isolation of SMSV-6 from a Steller sea lion represents, to our knowledge, the first isolation of any virus from this widely distributed marine mammal species, and serves to reconfirm the host-nonspecificity of yet another calicivirus of marine origin.

Animals↗
PubMed1986

Antibodies to marine caliciviruses in the Pacific walrus (Odobenus rosmarus divergens Illiger).

Sera from 155 Pacific walruses (Odobenus rosmarus divergens Illiger), sampled in the Chukchi Sea during the summer of 1983, were tested for serum neutralizing (SN) antibodies to six marine calicivirus serotypes. Serotypes tested included San Miguel sea lion virus (SMSV) types 1, 5, 8, and 10, previously isolated from northern fur seals (Callorhinus ursinus Linné) in the Bering Sea; walrus calicivirus (WCV), previously isolated from walrus feces collected off sea ice in the Chukchi Sea; and Tillamook calicivirus (TCV), a bovine isolate from Oregon of suspected marine origin. No antibodies were found to SMSV-1, SMSV-10, or TCV. Antibodies to SMSV-5 were found in two animals (titers 1:20 and 1:160); antibodies to SMSV-8 were found in four animals (all 1:20); and antibodies to WCV were found in one animal (titer 1:40). Antibodies to WCV have been found in the Pacific walrus previously; however, this represents the first report of antibodies to any of the SMSV serotypes in this marine mammal.

Animals↗
PubMed1986

First isolation of calicivirus from reptiles and amphibians.

Calicivirus isolations were made from 4 poikilothermic species in a zoologic collection. Viruses were recovered from 8 asymptomatic Aruba Island rattlesnakes (Crotalus unicolor; rectal swab samples) and from 8 symptomatic animals (4 Aruba Island rattlesnakes, 2 Bell's horned frogs [Ceratophrys orata], 1 rock rattlesnake [C lepidus], and 1 eyelash viper [Bothrops schlegeli] tissue samples obtained at necropsy). On the basis of cross-neutralization test results, the 16 isolates were antigenically indistinguishable and were considered to represent a unique calicivirus serotype, tentatively designated reptilian calicivirus Crotalus type 1. These isolations could not be associated causally with any specific disease entity either in naturally infected poikilotherms or in experimentally infected snakes and pigs.

Animals↗
PubMed1986

ELISA tests for dapsone and pyrimethamine and their application in a malaria chemoprophylaxis programme.

Enzyme-linked immunosorbent asays (ELISAs) are described for determining levels of dapsone and pyrimethamine in urine. Both assays have a sensitivity of about 20 mug/l and are reproducible, but each produces some false positives. The problem of false positive reactions was partially obviated by requiring positive results in both assays. In a pilot study involving 50 children aged 3 months to 4 years who were given a single dose of Maloprim (pyrimethamine + dapsone), 75% were positive for dapsone 7 days after administration of the drug, while 25% were still positive 15 days after its administration. The corresponding proportions for pyrimethamine were 73% and 30%, respectively. Comparison of the results obtained in a larger chemoprophylaxis trial with those from the pilot study indicated that the assays described could be used to investigate whether antimalarials had been taken.

Child, Preschool↗
PubMed1985

Characterization of a new calicivirus isolated from feces of a dog.

Canine calicivirus (CaCV), isolated from feces of a dog with diarrhea, was readily propagated in cultures of canine cells and in a dolphin cell line. Serologic evidence indicated many dogs in at least one geographic area had been infected with CaCV, but its role as an etiologic agent of disease was not established. In cell culture most CaCV virions were strongly cell-associated making purification difficult. CaCV was established as a member of the Caliciviridae by morphology and physicochemical properties of virions (density, sedimentation rate, single major polypeptide, RNA genome size), although some of the properties differed slightly from those of previously described caliciviruses; evidence was also obtained for caliciviral RNA species in infected cells. Based on tests with antisera to numerous caliciviruses and presumed caliciviruses, CaCV appeared to be not closely related to any previously described virus except the stunting syndrome agent of chickens.

Animals↗
PubMed1985

Isolation and identification of caliciviruses from dogs with enteric infections.

Caliciviruses were isolated from 7 dogs and 1 captured coyote with enteritis. There was a high fatality rate in dogs 4 to 16 weeks of age. The occurrence in these dogs of concurrent infection with known enteric pathogens such as Salmonella sp, canine parvovirus, canine coronavirus, and canine rotavirus did not allow making any conclusions regarding the pathogenicity of this newly recognized calicivirus. The caliciviruses were characterized by electron microscopy and were further identified as being closely related to feline calicivirus by immunoelectron microscopy with specific antibody.

Animals↗
PubMed1985

Calicivirus isolation from three species of primates: an incidental finding.

Calicivirus isolations were made from 3 species of subhuman primates. Viruses were recovered from gingival lesions associated with periodontal disease in a spider monkey, from the oropharynx of a healthy silver leaf langur, and from the spleen of a lowland gorilla that had died of systemic coccidioidomycosis. Based on the results of cross-neutralization tests, all 3 isolates were serologically indistinguishable from a primate calicivirus Pan paniscus type 1. These isolations appeared to be incidental in nature and could not be associated causally with any specific disease entity.

Animals↗
PubMed1985

Immunisation of cattle with a recombinant togavirus-vaccinia virus strain.

Genetic engineering techniques have been used to construct a vaccinia virus recombinant which contains and expresses togavirus (Sindbis) genetic information. Intradermal inoculation of this recombinant strain into calves caused a transient pock-type lesion at the site of inoculation and elicited the production of substantial levels of anti-Sindbis virus neutralising antibodies. These results suggest that recombinant vaccinia virus vaccines may have potential for use in veterinary medicine.

Animals↗