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Biomedical subjects

L Newberry

Publications and source records attributed to L Newberry.

6 recordsLinked to original sources
PubMed2004

Typing of Haemophilus paragallinarum strains by using enterobacterial repetitive intergenic consensus-based polymerase chain reaction.

The enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique was used for fingerprinting of reference strains and Mexican isolates of Haemophilus paragallinarum. A total of nine ERIC patterns were given by the nine serovar reference strains of this bacteria. Two Modesto (C-2) reference strains from different sources showed the same ERIC pattern. Seventeen ERIC patterns were obtained among 29 Mexican isolates included in the study, belonging to serovars prevalent in Mexico (A-1, A-2, B-1, and C-2). Obtained results indicate that the ERIC-PCR technique could be used as a molecular laboratory tool for subtyping of H. paragallinarum.

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PubMed1991

Action spectrum of antiviral factor from chicken sera.

Rous sarcoma virus infections of regressor line chickens stimulate the transient production of antiviral factors in the serum. Earlier the present authors reported that a viral neutralization factor (VNF) inactivated Rous sarcoma virus during a 3-h incubation. The VNF is likely to have a broad antiviral and antimicrobial spectrum because it is active against several unrelated pathogenic poultry viruses. The present study measured the activity of VNF against Newcastle disease virus, infectious bursal disease virus, and infectious bronchitis virus. The VNF is active in immunologically incompetent systems and must be preincubated with the virus in order to inhibit it. Based upon the current experiments, it is proposed that VNF is not an immunomodulator but directly inactivates the virus. The VNF agent appears to be one of a newly identified class of nonspecific antiviral agents produced in vivo in chickens in response to a viral infection.

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PubMedDate not supplied

Changes in serum ovotransferrin levels in chickens with experimentally induced inflammation and diseases.

A competitive enzyme immunoassay was developed to measure the changes in serum levels of ovotransferrin (OTF) during inflammation and infectious diseases in chickens. The assay is based on the competition of serum OTF with a fixed concentration of biotin-labeled OTF to bind to a rabbit anti-chicken transferrin antibody immobilized on microtiter wells. After several washing steps, the antibody-bound biotinylated OTF is probed with streptavidin-horseradish peroxidase conjugate (HRP) followed by a colorimetric detection of the HRP activity. The relative changes in the optical density of color are plotted against the competing concentrations of OTF with logarithmic regression to generate a standard curve that is used to determine the concentrations of OTF in unknown samples. Serum had no effect on the measurement of OTE By this method, the time course changes of serum OTF levels in 4-wk-old male broiler chickens that were subjected to inflammation by croton oil injection were measured. The results showed croton oil-induced inflammation elevated serum OTF levels at 16 hr postinjection. OTF levels reached a peak by 72 hr, remained high through 120 hr, and returned to a basal level of olive oil-injected controls by 240 hr. There were no changes in serum OTF levels at any of the above time points in olive oil-injected control chickens. For studies with poultry diseases, specific-pathogen-free (SPF) male chickens were challenged with known bacterial and viral pathogens, and serum was collected at the height of the infection, i.e., 7 days after the challenge. Compared with uninjected controls, the SPF chickens challenged with Escherichia coli, fowl poxvirus, respiratory enteric orphan virus, infectious bursal disease virus, infectious bronchitis virus, or infectious laryngotracheitis virus had higher levels of OTF in serum. Inflammation-induced changes in serum OTF levels were also evident in the changes in the density of a 65-kD band protein corresponding to OTF. These results demonstrate that serum OTF may be a nonspecific clinical marker of inflammation associated with traumatic or infectious avian diseases.

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