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Background: The Chiron Procleix HIV-1/HCV Assay is a qualitative nucleic acid assay system for the detection of HIV-1 and HCV virus RNA in human plasma. The TIGRIS analyzer is under development as an integrated nucleic acid testing system, which fully automates all steps necessary to perform the Chiron Procleix HIV-1/HCV Assay, from sample processing through amplification and detection. Features such as specimen barcode reading, compatibility with a wide range of sample tubes, automated worklist creation, a Reagent Dispense Verification system and high throughput make the Tigris system suitable for medium and high volume screening of blood and plasma donations. Methods: Performance of the Procleix HIV-1/HCV Assay has been tested on the TIGRIS system on multiple instruments over a period of three months using sensitivity panels. Results: The assay sensitivity on the TIGRIS instrument was 99.5% (2349/2360) for 100 c/ml HIV-1 and 98.8% (2334/2362) for 30 c/ml HIV-1. For HCV virus detection, assay sensitivity was 99.9% (2356/2358) and 98.2% (2284/2325) at 100 c/ml and 30 c/ml, respectively. Initial reactive rate with a negative panel was 0.18% (4/2258) and Internal Control failure rate was 0.24% (32/13,340). The instrument throughput is greater than 400 tests in 8 hours. No false positive results were obtained when negative samples were interspersed in the same worklist with high positive HIV-1 samples containing 10[sup 9] c/ml. A 100% positivity rate for HIV-1 and HCV at 100 c/ml was obtained when sensitivity panels were spiked with putative interfering substances at the following concentrations: bilirubin at 200 mg/L (20 times normal level), hemoglobin at 5 g/L (500 times normal level), protein at 187.5 g/L (2.5 times normal level) and lipids at 2752 mg/dl (15 times normal level). The Reagent Dispense Verification system was shown to be effective in detection of inaccurate reagent addition when the instrument was tested under induced faulty operational states. Conclusion: The Chiron Procleix HIV1/HCV Assay on the TIGRIS system meets performance requirements for screening of blood donations. [ABSTRACT FROM AUTHOR]

The use of attenuated vaccines or the occurrence of low virulent T-lymphotropic or B-lymphotropic viruses in flocks may alter the immune responses of young chicks in spite of the absence of clinical signs. Infections with a low virulent T-lymphotropic chicken infectious anaemia virus (lvCIAV) followed by infection with an intermediate B-lymphotropic infectious bursal disease virus (iIBDV) were conducted in specific pathogen free chicks. Thirty-six 1-day-old chicks were infected with the lvCIAV strain (CAV-VAC®) and a similar number of chicks were inoculated with phosphate-buffered saline. At 14 days after lvCIAV infection, one group of 18 lvCIAV-infected chicks and one group of 18 uninfected chicks were infected with an iIBDV strain. At 4, 7 and 14 days post infection with iIBDV, six chicks from each group were euthanized and lymphoid organs were collected. Detection of lvCIAV and iIBDV genomes was conducted by polymerase chain reaction and reverse transcriptase-polymerase chain reaction, respectively. Double-labelled lymphoid subsets from the thymus, spleen and bursa were studied by cytofluorometric analysis. The results reveal that previous infection with lvCIAV increases the occurrence of the lvCIAV and iIBDV genome in thymus and/or bursa without the occurrence of clinical signs in dually lvCIAV/iIBDV-infected chicks. However, the decreases of B cells in spleen and bursa and increases of T-cell subsets in bursa observed in chicks infected with iIBDV did not occur in chicks previously infected with lvCIAV. Taken together, these results suggest that previous infection of young chicks with lvCIAV decreases lymphoid disorders induced by iIBDV while subsequent iIBDV infection increases the lvCIAV genome in lymphoid organs.

The chicken infectious anaemia virus (CIAV) infection may induce immunosuppression and persistent infection. The use of vaccination in young chicks is still controversial due to its low immune efficiency. In order to verify the viral persistency of a vaccinal strain of CIAV and its associated-lymphoid cell disorders, 54 1-day-old specific pathogen free chicks were vaccinated (CIAV-VAC(®); Intervet, Millsboro, Delaware, USA) and haematologic examination, expression of viral VP3 gene, humoral response and phenotyping of lymphoid cells were studied in lymphoid organs at various times post vaccination (p.v.). No clinical signs were observed but light heteropaenia was detected in CIAV-vaccinated chicks. The VP3 gene of CIAV was detected by polymerase chain reaction in the thymus and spleen from day 7 until 28 days p.v. Thymic larger CD4(+)CD8(+) cells increased only at 7 days p.v. while smaller CD4(+)CD8(+) cells decreased after 14 and 28 days in CIAV-vaccinated birds. The CD4 expression, in contrast to that seen for CD8, decreased in thymocytes from the CIAV-vaccinated group. In the spleen and bursa, the percentage of CD8(+) cells increased at 7 and 28 days p.v. only, while CD4(+) cells decreased simultaneously. The vaccinated chicks also exhibited a higher number of splenic CD3(-)CD8(+) cells (natural killer cells). The anti-CIAV antibody responses, however, remained low in most vaccinated chicks and did not persist up to 18 days p.v. These results suggest that the vaccinal virus strain is clinically attenuated but persists in the thymus and spleen in some birds, inducing a low humoral immune response and altering thymopoiesis.

Introduction: Health regulatory colleges promote continued competence by requiring members to submit yearly portfolios that document learning. Previous studies conclude that portfolios can be valuable tools to promote continuous learning in health college members, but portfolios are time-consuming to complete and difficult to evaluate. This exploratory study compares the features of portfolio models in regulatory colleges, as a basis for future studies., Methods: Data were collected through a document review of the portfolio models described on the Web sites of 14 Canadian health regulatory colleges., Results: All models contain 3 common components of self-directed learning: (1) self-diagnosis, (2) learning plan and activities, and (3) self-evaluation. Several include member profiles and peer feedback. A broad range of formal, nonformal, and informal activities are accepted as evidence of learning; a few colleges restrict learners' freedom in selecting these activities., Discussion: There is a dual philosophy of learning in portfolio models that includes both humanist and technical paradigms. Low numbers of members are selected for audit of completed portfolios. The possibility of last-minute preparation and the lack of support to members who struggle with self-directed learning methods are issues to be resolved. Although portfolios are designed to enhance learning and reflection, quality cannot be ensured unless compliance is enforced, and learning outcomes are measured. Professionals should be guided regarding how to complete portfolios. More health regulatory colleges should announce the number of portfolios they audit. In general, the number of portfolios audited by each profession may need to be increased.

Growth rate in broiler birds has increased substantially in the last decade due to improvement in genetics, feed formulation, cleaner environment, and vaccine formulations. As a result, it has become necessary to review and revise prediction method for vaccination in chicks. This study was undertaken to determine the possible use of the rate of weight gain rather than age in predicting vaccination time. Two groups of 1-day-old broilers originating from old and young breeders, respectively, and with different levels of maternal antibodies against infectious bursal disease virus (IBDV) were used in this study. The chicks were divided into four groups and subjected to two feed regiments: groups A1 and B1 were fed broiler feed for normal growth rate, and groups A2 and B2 were fed breeder feed for slower growth rate. At 1, 4, 8, 12, 16, 22, 29, and 36 days of age, 22 chicks in each group were weighed, and blood samples were collected. Serum samples were tested for antibodies against IBDV by enzyme-linked immunosorbent assay (ELISA) and virus neutralization test. Maternal antibody decline curves for each group were plotted according to chick age and chick weight. Fast-growing birds in groups A1 and B1 showed a faster rate of antibody decline, whereas slow-growing birds in groups A2 and B2 had a slower rate of antibody decline. Based on the effect of weight gain on maternal antibody decline, a new way of predicting vaccination time for IBDV based on measuring maternal antibody titers at 4 days of age was proposed and tested. The predicted antibody decline was shown to correspond to the real ELISA titers measured in our experiments (R = 0.9889), whereas a lower correlation (R = 0.8355) was detected between real ELISA titers and the titers predicted by the current method using age-based Deventer formula.