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Biomedical subjects

A Wiseman

Publications and source records attributed to A Wiseman.

At least 37 records · Page 2Linked to original sources

Immunogenicity of a low-passage, high-titer modified live canine parvovirus vaccine in pups with maternally derived antibodies.

The study evaluated the ability of a low-passage, high-titer modified live canine parvovirus (CPV) vaccine to produce seroconversion in pups with maternally derived hemagglutination inhibition (HI) titers ranging from < 8 to < or = 256. The vaccine's low-passage CPV strain was less attenuated and therefore more infective than conventional modified live CPV strains in order to overcome relatively greater levels of maternally derived antibodies, the principal cause of CPV vaccine failures in pups. To assess vaccine performance under field conditions, healthy pups presented at five private veterinary clinics were used as test animals. A single dose of vaccine was given to 59 pups at 12 weeks of age (Group A). To accommodate the protocol of clinics where earlier CPV vaccination was practiced, 87 other pups were vaccinated with two doses, the first at 8-10 weeks of age, and the second at 12 weeks of age (Group B). Geometric mean HI titers were measured for blood samples obtained at the time of vaccination and at 14 weeks of age. Seroconversion was considered to have occurred if pups developed a fourfold or greater increase in HI titer to a level > or = 64. Of the 59 pups in Group A, 100% seroconverted following the single vaccine dose at 12 weeks of age. Of the 87 Group B pups, 82 (94.3%) seroconverted following either of the two vaccine doses. A geometric mean HI titer of 4828 was measured for Group A, and a geometric mean HI titer of 2028 was measured for Group B. An overall seroconversion rate of 96.5% was achieved in pups with maternally derived HI titers < or = 256.

Animals↗

Therapeutic proteins and enzymes from genetically engineered yeasts.

Human proteins, including enzymes, manufactured with recombinant-DNA yeasts can be used to treat a variety of medical conditions; some redesign of molecular structure (and production techniques) should increase their specificity, efficacy and immunotolerance. Prevention and treatment of diseases due to reactive oxygen species (ROS) and reactive nitrogen species (RNS) may become possible. Therapeutic vaccines for some diseases may be produced by design-specification for particular desirable protein features, on an individual patient basis.

DNA, Recombinant↗

Designer enzyme and cell applications in industry and in environmental monitoring.

Renewed world interest in enzyme biotechnological industries now derives from the expectation that many new biocatalysts will be created by genetic engineering associated with protein engineering designer techniques, or by chemical modification of existing enzymes by use of protein tailoring methods. The biocatalysts produced are mainly enzymes, abzymes (catalytic antibodies) and synzymes (synthetic analogues or mimics), and these will be used in industry, synthesis, therapy: and in bioanalysis of components of foodstuffs, and the environment including water, air and soil. The biocatalysts, including whole cells, are firstly incorporated into a particular bioreactor form by use of enzyme engineering techniques such as immobilization, and are then used, as appropriate, to modify their substrates. Improved processing or enhanced products are thereby achieved in the case of manufacturing industry: or monitoring signals are generated, often in the form of a measurable change in current flow, in the case of environmental biosensors. Designer enzymes and cells can be made now for identified applications where the presently available biocatalysts are inadequate, incompatible or uncompetitive.

Biotechnology↗

Genetically-engineered mammalian cytochromes P-450 from yeasts--potential applications.

High-activity forms of mammalian cytochromes P-450 have now been expressed in yeast. Some members of this superfamily of enzymes detoxify drugs, whilst others activate carcinogens, or interconvert steroid hormones. Applications for these previously unavailable forms of cytochrome P-450 can now be developed, including the biosynthesis of hydroxylated compounds, bioanalysis and tests for hazardous substrates of these enzymes, and therapeutic detoxification devices. All of these applications could use protein-engineered, or protein-tailored enzymes in immobilized form.

Animals↗

Mice expressing a bovine basic fibroblast growth factor transgene in the brain show increased resistance to hypoxemic-ischemic cerebral damage.

BACKGROUND AND PURPOSE: Cerebral intraventricular infusion of acidic or basic fibroblast growth factor has been shown to attenuate ischemic damage to hippocampal CA1 neurons in the gerbil. The purpose of the present study was to determine if the basic fibroblast growth factor transgenic mouse has an enhanced ability to resist the effects of severe cerebral hypoxemia-oligemia. METHODS: Mice that were transgenic for bovine basic fibroblast growth factor were exposed to right carotid artery ligation, hyperglycemia, and 20 minutes of 1% carbon monoxide. After 5 days' recovery, brains were examined for histological damage. RESULTS: Counts of CA1 neurons in the right hippocampus showed a significantly higher number of neurons per millimeter CA1 in hypoxic-ischemic transgenic mice compared with nontransgenic controls (transgenic, 260 +/- 33; nontransgenic, 151 +/- 37 neurons per millimeter CA1; P < .05). CONCLUSIONS: The results indicate that basic fibroblast growth factor transgenic mice, as judged by CA1 hippocampal neuronal survival, have an enhanced ability to resist the effects of a complex hypoxic-ischemic cerebral insult.

Animals↗

Evaluation of an atrophic rhinitis vaccine under controlled conditions.

A vaccine containing inactivated cultures of Bordetella bronchiseptica, toxigenic Pasteurella multocida type D and dermonecrotic P multocida type D toxoid in an oil-in-water adjuvant was given to seven sows, with seven others acting as controls. Half the piglets in each litter were exposed intranasally when four days old to B bronchiseptica and when eight days old to toxigenic P multocida type D. There was considerably less sneezing in the litters of the vaccinated sows and when the piglets were 10 weeks old, only 18 per cent had deformed snouts compared with 74 per cent in the litters of the control sows. The average liveweight gain of the piglets born to vaccinated sows was significantly better (P less than 0.05) between two and 10 weeks of age than that of the piglets born to unvaccinated sows, although there were no significant lower respiratory tract lesions in either group. The conchal atrophy scores were significantly lower (P less than 0.001) in the piglets from the vaccinated sows and were negatively correlated (r = -0.37) with increasing liveweight gain. In the liters of the vaccinated sows, P multocida was not isolated from the nasal passages of the in-contact piglets and from only 7 per cent of those deliberately exposed compared with 65 per cent and 79 per cent, respectively, in the litters of the control sows. P multocida was isolated post mortem from the tonsils of 23 per cent of the piglets of vaccinated sows and from 87 per cent of those from unvaccinated sows.

Animals↗

The organisation of production of genetically-engineered proteins in yeast.

The use of a variety of genetic-engineering techniques to introduce foreign DNA into living yeast cells has resulted in the production in these cells of the corresponding proteins. These include enzymes, antibodies, vaccines, anti-viral agents, and hormones. This article discusses the techniques of genetic engineering in yeast and suggests the lines of future progress in the economic production of novel proteins for use in therapy.

Plasmids↗

Performance of high titre attenuated canine parvovirus vaccine in pups with maternally derived antibody.

The performance of live, attenuated, homologous, canine parvovirus vaccines was studied in 140 puppies aged from four to 11 weeks. In the presence of maternally derived antibody the ability of the vaccines to elicit a serological response, as determined by the haemagglutination inhibition test and a standardised ELISA, was found to be dose (infectious titre) related. An experimental vaccine containing 10(7.0) TCID50 of virus induced seroconversion rates of 95, 89, 82 and 44 per cent in dogs with haemagglutination inhibition antibody titres of less than or equal to 8, 16, 32 and greater than 32, respectively. The standardised ELISA appeared to be better than the haemagglutination inhibition test with respect to variability and subjectivity, especially when titres were low.

Animals↗

An IgM specific ELISA for the serodiagnosis of viral bovine respiratory infections.

A capture ELISA for the detection of IgM antibodies to Infectious Bovine Rhinotracheitis (IBR) and to Bovine Respiratory Syncytial (BRS) viruses was developed. In these assays, the first monoclonal antibody to bovine IgM is used as the catching antibody while the second monoclonal detects specific antiviral antibodies. The test was evaluated on serum samples originating from both experimentally and naturally infected animals. From these studies, it has been shown that primary IBR and BRS virus infections can be confirmed using serum samples collected 5-10 days after the appearance of the clinical signs of disease.

Animals↗

Distribution of Pasteurella haemolytica in the respiratory tracts of carrier calves and those subsequently infected experimentally with Dictyocaulus viviparus.

Distribution of Pasteurella haemolytica in the respiratory tracts of calves with no apparent clinical signs of illness and those infected experimentally with Dictyocaulus viviparus was determined so as to define carrier sites for this organism. The calves had been positive by nasopharyngeal swab for either P haemolytica A2 or A1 for at least two months or for over a month, respectively, before slaughter. P haemolytica A1 was acquired following horizontal spread from other infected calves. It was observed post mortem that P haemolytica A1 or A2 resided in the tonsils and retropharyngeal lymph nodes of calves of both groups. In addition to these sites, P haemolytica A1 was also isolated from the right cranial lung lobe of one of the calves from the D viviparus infected group although there was no evidence of pasteurella associated pneumonia. It was concluded that tonsil and retropharyngeal lymph nodes appear to be the most important carrier sites for P haemolytica when compared to other tissues of the bovine respiratory tract.

Animals↗