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Biomedical subjects

L L Rodriguez

Publications and source records attributed to L L Rodriguez.

24 records · Page 2Linked to original sources
PubMed1990

Vesicular stomatitis New Jersey virus glycoprotein gene sequence and neutralizing epitope stability in an enzootic focus.

Vesicular stomatitis New Jersey (VS NJ) virus is capable of undergoing rapid evolution in nature and therefore has the potential for antigenic variation. We selected an area of Costa Rica where VS NJ virus is enzootic to study whether this virus used the mechanism of antigenic variation to persist in nature. Three sentinel herds and three nonsentinel herds were observed from 1986 to 1988. Eleven VS NJ virus isolates were collected from naturally infected cattle. Remarkably, nine animals that were bled prior to reinfection with VS NJ virus had neutralizing antibody titers up to 1: 102,400 yet virus was isolated from, and disease was observed in, these animals. Sequence analysis of the portion of the glycoprotein gene coding for the neutralizing epitopes demonstrated that all virus isolates were 98-100% similar with no indication of specific genetic variation. The 3' end of the glycoprotein gene also remained stable in that all isolates were again 98-100% similar in nucleotide sequence. Each isolate was neutralized to equivalent titers with monoclonal antibodies directed against four neutralizing epitopes on the glycoprotein. Additionally, preisolation sera from each animal were able to neutralize the virus that caused the subsequent disease. These results provide evidence that antigenic variation is not a mechanism used by VS NJ virus to persist in an enzootic focus of Costa Rica.

Animals↗
PubMed1990

Serological monitoring of vesicular stomatitis New Jersey virus in enzootic regions of Costa Rica.

The activity of vesicular stomatitis viruses was monitored on 3 dairy farms in Costa Rica. Antibody levels were measured and clinical disease monitored in 165 cattle during a 20 month period (1986-1988). Vesicular stomatitis New Jersey (VS NJ) virus was shown to be enzootic on these farms by a 94.2% prevalence of neutralizing antibody; this did not vary significantly between herds. The mean prevalence of antibody to vesicular stomatitis Indiana (VS IN) virus was 15.2%, but was significantly higher in 1 herd. A total of 25 cases (annual incidence rate of 9%) of clinical vesicular stomatitis (VS) was reported. VS NJ virus was identified as the causal agent by detection of VS NJ virus antigens by the complement fixation test. VS NJ virus was isolated in 11 cases. All episodes of disease occurred between November and January, the beginning of the dry season. Most animals maintained stable neutralizing antibody titers throughout the study, and all diseased animals were previously seropositive to VS NJ virus. A total of 31 animals with neutralizing antibodies to VS NJ virus had a VS NJ virus-specific IgM response, and 6 animals had IgM responses that persisted for as long as 6 months. There was no relation between IgM responses and clinical disease occurrence. VS NJ virus persisted predominantly as a subclinical infection in cattle throughout the year in enzootic areas of Costa Rica. The humoral response did not prevent reinfection with VS NJ virus.

Animals↗
PubMed1986

Characterization of envelope proteins of infectious bovine rhinotracheitis virus (bovine herpesvirus 1) by biochemical and immunological methods.

Ten glycoproteins of molecular weights of 180,000, 150,000, 130,000, 115,000, 97,000, 77,000, 74,000, 64,000, 55,000, and 45,000 (designated as 180K, 150K, etc.) and a single nonglycosylated 107,000-molecular-weight (107K) protein were quantitatively removed from purified bovine herpesvirus 1 (BHV-1) virions by detergent treatment. Immunoprecipitations with monospecific and monoclonal antibodies showed that three sets of coprecipitating glycoproteins, 180K/97K, 150K/77K, and 130K/74K/55K, were the major components of the BHV-1 envelope. These glycoproteins were present in the envelope of the virion and on the surface of BHV-1-infected cells and reacted with neutralizing monoclonal and monospecific antibodies. Antibodies to 150K/77K protein had the largest proportion of virus-neutralizing antibodies, followed by antibodies to 180K/97K protein. Monoclonal antibodies to 130K/74K/55K protein were neutralizing but only in the presence of complement; however, monospecific antisera produced with 55K protein did not have neutralizing activity. Analysis under nonreducing conditions showed that the 74K and 55K proteins interact through disulfide bonds to form the 130K molecule. Partial proteolysis studies showed that the 180K protein was a dimeric form of the 97K protein and that the 150K protein was a dimer of the 77K protein, but these dimers were not linked by disulfide bonds. The 107K protein was not glycosylated and induced antibodies that did not neutralize BHV-1. The 64K protein was not precipitated by anti-BHV-1 convalescent antisera, and monospecific antisera to this protein precipitated several polypeptides from uninfected cell lysates, suggesting that 64K is a protein of cellular origin associated with the BHV-1 virion envelope.

Animals↗
PubMed1984

Characterization of bovine herpesvirus-1 isolated from trigeminal ganglia of clinically healthy cattle.

Isolates of bovine herpesvirus-1 (BHV-1) recovered from tissue explants of trigeminal ganglia of clinically healthy cattle were studied in vitro and in an animal model, and their characteristics were compared with those of vaccine and field strains of BHV-1. The isolates could be distinguished by their plaque size on cell monolayers, but were not significantly different in their thermal inactivation profiles at 48 C. Temperature-sensitive mutants were not found among the isolates when they were grown at 41 C. Selected isolates had different pathogenicity when inoculated in young rabbits.

Adrenal Glands↗
PubMed1979

Organochlorine pesticide residues in soils from six U.S. Air Force bases, 1975--76.

Soil samples collected during 1975 and 1976 from United States Air Force installations in California, Georgia, Ohio, Oklahoma, Texas, and Utah were analyzed for organochlorine pesticide residues. Sigma DDT, chlordane, and dieldrin were the pesticides most commonly found. In 1975, sigma DDT residues were significantly higher in samples from residential areas than in samples from golf courses or areas free of pesticide application. Chlordane residues in 1975 were significantly higher in both residential and golf course areas than in areas where pesticides had not been used. No significant differences were found in 1976 in residue levels of any pesticide monitored among various land use areas.

Hydrocarbons, Chlorinated↗