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Biomedical subjects

D J Briggs

Publications and source records attributed to D J Briggs.

33 records · Page 2Linked to original sources
PubMed1995

Lectin histochemistry of normal and herpesvirus-infected bovine nasal mucosa.

Proliferation of Pasteurella haemolytica serotype 1 in the nasal cavity following stress or viral infection is an important event in the pathogenesis of bovine pneumonic pasteurellosis. Enhanced adhesion of P. haemolytica to nasal mucosa could be one factor that predisposes animals to this proliferation. Nasal mucosa from normal and bovine herpesvirus-1 (BHV1)-infected cattle were examined histochemically for their glycoconjugate composition. Twenty lectins were screened, six of which were chosen for subsequent study. Three of these were specific for N-acetylgalactosamine (NAGal) (Dolichos biflorus, Glycine max, and Vicia villosa), and one each was specific for N-acetylgalactosamine/galactose (Griffonia simplicifolia-I), mannose/glucose (Canavalia ensiformis), and N-acetylglucosamine (Triticum vulgaris). For the surface mucosa and submucosal glands, there was greater reactivity in samples from BHV1-infected than from normal cattle for all six lectins. Reactivity was most prominent for the NAGal-specific lectins. Neuraminidase treatment of samples from normal and BHV1-infected cattle tended to result in greater lectin reactivity. Lectin reactivity was generally more intense in focally inflamed areas, but diffuse reactivity was not substantially affected by inflammation. BHV1-induced alteration of nasal mucosal glycoconjugates could enhance adhesion and colonization of P. haemolytica to nasal surfaces and may be one factor responsible for the increased number of P. haemolytica serotype 1 in the nasal cavity following viral infection.

Animals↗
PubMed1995

Developing indicators for environment and health.

This article demonstrates the need for indicators in the policy-making process and presents some of the current work on developing environmental indicators at the international, national and local levels. The paucity of indicators to demonstrate relationships between environment and health is outlined and a causal chain for physical pollutants--from source activity to emission, concentration and exposure--is presented. While indicators can be developed at each of these stages, indicators from earlier in the chain reflect processes which can more readily be controlled by policy; data is also more readily available for these indicators, yet only the later indicators are likely to provide a reliable guide to human exposure. A survey of 26 indicator projects from around the world yielded 8 sets which are in use and for which data exists. These were found to be only partially health-related and heavily weighted towards the source activity indicator category. Their utility as reliable indicators of human exposure is therefore seriously open to doubt and there is consequently a need to develop indicators specifically to assess environmental and health relationships.

Bias↗
PubMed1995

The use of geographical information systems in studies on environment and health.

Geographical information systems (GIS) provide a powerful technology for the spatial analysis of environmental and health data. Major areas of application include the assessment and mapping of environmental exposure, mapping of health outcome, and the analysis of spatial relationships between environment and health. The use of GIS nevertheless brings with it many potential problems and pitfalls. This article reviews some of the recent applications in relation to studies of environment and health, and examines some of the research issues involved.

Bias↗
PubMed1993

Risk factors for systemic hypersensitivity reactions after booster vaccinations with human diploid cell rabies vaccine: a nationwide prospective study.

To determine the incidence of and risk factors for adverse reactions following the boosters, we conducted a nationwide prospective study of persons receiving pre-exposure booster vaccination with human diploid cell rabies vaccine (HDCV). Persons who had previously received three pre-exposure doses of HDCV and whose rabies neutralizing antibody titres were < or = 1:5 were enrolled in the study if they stated that they intended to receive a booster. Of the 98 persons enrolled in the study, 40 (41%) were in risk groups for whom boosters are not recommended. Three (3%) of 98 developed generalized urticaria or wheezing within 1 day of receiving boosters and three others (3%) developed urticaria 6 to 14 days after the booster. No differences were found between individuals with reactions (either type) and those with no adverse reaction according to age, gender, occupation, history of previous allergies, or time since or route of primary vaccination. Reactions were somewhat more common among persons who received primary vaccinations by the intramuscular route (i.m.) and booster vaccinations by the intradermal route (i.d.) (3/15, 20%) or primary vaccinations i.d. and booster vaccinations i.m. (2/10, 20%), and somewhat less common among persons who received both these vaccinations i.d. (1/52, 2%) or i.m. (0/7). The number of persons who develop allergic reactions may be minimized by administering vaccinations only when vaccination is strictly indicated. The influence of the route of primary and booster vaccinations on the development of reactions deserves further study.

Adult↗
PubMed1992

Longevity of rabies antibody titre in recipients of human diploid cell rabies vaccine.

Sera from individuals across the USA and Peace Corps Volunteers (PCV) were assayed for neutralizing antibody to human diploid cell rabies vaccine (HDCV). A pairwise comparison between intramuscular (i.m.) and intradermal (i.d.) administration, PCV and non-PCV, revealed statistically significant differences between i.m. and i.d. for PCV and non-PCV, and between PCV and non-PCV for i.d. and i.m. administration. Survival analysis and frequency tables employing chi 2 tests determined that the percentage probability of maintaining an adequate titre from 1.5-2.0 years after primary vaccination was 99% in non-PCV i.m., 93% in non-PCV i.d., 88% in PCV i.m., and 64% in PCV i.d.

Adolescent↗
PubMed1992

Binding rate of rabies virus to alpha interferon primed mouse neuroblastoma cells.

Mouse neuroblastoma cells (MNA) were primed with 20 I.U. of alpha interferon (Mu IFN-alpha) prior to exposure to the Challenge Virus Standard strain of rabies virus (CVS). Saturation of CVS receptor sites occurred when 0.71 microgram of 3H-CVS protein bound to 20,000 MNA cells. After 180 min incubation time, the amount of viral protein attributed to specific binding was estimated to be 0.45 microgram. Mu IFN-alpha treatment of MAN cells did not increase the number of specific cell receptor sites to CVS but it did significantly increase the rate that CVS was able to bind to cell receptors. The amount of time required to reach saturation of MNA cell receptors to CVS decreased from 120 min in untreated cells to 30 min in Mu IFN-alpha primed MNA cells. Although treatment with Mu IFN-alpha increased the binding rate of rabies virus to MNA cells, the virus was unable to complete a productive infection 48 hrs after the Mu IFN-alpha was removed.

Animals↗
PubMed1991

The effect of neurotoxin on rabies virus binding to mouse neuroblastoma cells.

Mouse neuroblastoma cells were exposed to alpha bungarotoxin, a neurotoxin known to inhibit rabies virus binding to the nicotinic acetylcholine receptor located at the neuromuscular junction in muscle tissue. The total amount of 3H-CVS virus that bound to neurotoxin treated cells was separated into specific and non-specific binding using a cold competition assay. Comparison of untreated and neurotoxin treated cells demonstrated that the majority of cell-associated virus in untreated cells was of a specific nature whereas the majority of the cell-associated virus in neurotoxin treated cells was due to non-specific binding.

Animals↗
PubMed1987

Comparative prevalence of rabies antibodies among household and unclaimed/stray dogs as determined by the immune adherence haemagglutination assay.

The immune adherence haemagglutination assay (IAHA), widely used for human viral disease diagnosis, has been adapted for detection of rabies virus antibodies in dog sera. Rabies virus antibody titres obtained by the IAHA correlated well with those obtained by the currently accepted test for rabies antibody determination, the rapid-fluorescent-focus-inhibition test (RFFIT). Although it is not known if the antibodies detected in IAHA test represent neutralizing antibodies against rabies, IAHA has several advantages over the RFFIT: the IAHA is rapid, requiring about seven hours for results to be available; it is relatively inexpensive and easy to perform; uses reagents commonly available in any routine virology laboratory; and uses inactivated rabies virus, thus eliminating hazards associated with the use of live virus in RFFIT. Using this test we found that rabies antibody titres were significantly higher, and at the same time more prevalent, among household dogs than among the unclaimed/stray dogs. The results re-emphasize the increased hazard associated with unclaimed/stray dogs and the need for vaccination of all dogs.

Animals↗
PubMedDate not supplied

Informing environmental health policy in urban areas: the HEADLAMP approach.

Urban areas represent complex environments in which to protect health. Accurate and highly resolved information is thus a prerequisite for effective environmental health policy. The HEADLAMP approach is designed to improve decision-making by providing indicators, based on sound science, to all relevant stakeholders, in an appropriate and usable form. The approach comprises three linked stages: categorization of the issues to be addressed, construction of relevant indicators, and policy formulation and implementation. Nevertheless, the application of this approach faces many challenges. The environment-health chain is both lengthy and complex, so that a wide range of indicators is needed from different points in this chain. The DPSEEA framework provides a useful, though limited, structure to help define and organize these indicators. This complexity also means that the indicators have to be linked, so that problems can be tracked from cause to effect and the effectiveness of actions at different points in the DPSEEA chain can be evaluated. Indicators also have to be designed in ways reflecting the spatial and temporal complexity of urban areas--namely, the rapid rates of change in urban environments and the marked spatial variations in environmental and sociodemographic conditions. Effective methods of participation are equally essential if the indicators are to represent the concerns of the stakeholders involved, and if decisions are to be made on a collective basis. Good indicators thus must be designed to fit many different and varying purposes. The challenge is to devise indicators that serve these purposes by representing the intricacies that are inherent in urban areas, rather than by hiding that complexity.

Data Collection↗
PubMedDate not supplied

Application of the positive/negative ratio method of analysis to quantitate antibody responses to infectious bursal disease virus using a commercially available ELISA.

An enzyme-linked immunosorbent assay (ELISA) test kit has been developed for infectious bursal disease virus (IBDV), and it is widely used for the detection and quantification of IBDV antibody. With results obtained using the commercial kit, a method of analysis was performed utilizing a positive/negative (P/N) ratio standard curve. A prediction equation was derived from this analysis by which the ELISA titer of a serum sample could be determined using one serum dilution. Values obtained using this method were compared with values obtained by the virus-neutralization equivalent method recommended by the kit manufacturer. The results were comparable in that the trends in titer were similar. The P/N ratio standard curve method is another way of determining titer using the IBDV ELISA test kit.

Animals↗
PubMedDate not supplied

Probability of survival based on ELISA titer following challenge of vaccinated chickens with the X-73 strain of Pasteurella multocida.

The probability of survival of chickens following a challenge dose of the X-73 strain of Pasteurella multocida was calculated based on enzyme-linked immunosorbent assay (ELISA) titer. Chickens were vaccinated subcutaneously with the Clemson University strain of P. multocida. On days 3, 5, 7, 10, 12, 14, 21, and 28 post-vaccination, 10 vaccinated chickens and 5 unvaccinated controls were selected at random, bled, and then challenged with 2000 colony-forming units of X-73. The ELISA titers to P. multocida vaccination and responses to challenge were recorded. A logistic procedure predicted probability of survival related to ELISA titer. The ELISA titer and survival were highly correlated. A flock profile for each day of challenge was developed based on a probability of survival (PS) at the following levels: PS less than 25%, 25% less than or equal to PS less than 50%, 50% less than or equal to PS less than 75%, and PS greater than or equal to 75%. The antibody response of the chickens through 28 days post-vaccination demonstrated a classic response to vaccination.

Animals↗
PubMedDate not supplied

An enzyme-linked immunosorbent assay for detecting antibodies to Pasteurella multocida in chickens.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect the humoral antibody response in chickens receiving subcutaneous injections of the CU vaccine strain of Pasteurella multocida. Serum samples were collected twice weekly for 3 weeks, and chicken antibody responses were monitored using ELISA. The positive/negative ratio method of analysis was used to determine the antibody titer of vaccinated chickens. After a loge transformation of the ELISA titer, a linear relationship was confirmed between ELISA titer and positive/negative ratio. Regression analysis was used to construct a standard curve and derive an equation from this relationship. Using this equation, only one dilution was needed to determine the antibody titer of any unknown serum sample. The ELISA technique was used to monitor the mean antibody titer of vaccinated chickens over the 3-week period. A classic primary response curve occurred when titer was plotted against time.

Animals↗