I Van Vlaenderen

Compaction rate of in vitro fertilized bovine embryos related to the interval from insemination to first cleavage

A study was conducted on early cleavage divisions and timing of compaction in bovine preimplantation-stage embryos. Zygotes were produced using conventional in vitro maturation and fertilization procedures. Twenty hours post insemination, the zygotes were denuded and cultured with oviduct epithelial cells in B2 medium + 10% estrous cow serum. Starting at 24 hours post insemination, the embryos (n=657) were evaluated every 6 hours and then were put into different co-culture drops according to their cell number. Starting from 78 hours post insemination, the cleavage rate was evaluated every 12 hours. Embryos were stained with Hoechst 33342 at the compacted morula stage or when they were degenerated, at 162 hours post insemination. Developmentally capable embryos were characterized by a rapid cleavage rate in the first 3 cell cycles and by an extended 8- to 16-cell stage. Peak concentrations of 2-, 4-, 8- and 16-cell stages emerged at 36, 42, 60 and 102 hours post insemination, respectively. Compaction did not occur until 126 hours post insemination. The rate of compaction was significantly higher in embryos that were at the 2-cell stage before or at 36 hours post insemination (P < 0.05). The mean cell numbers of compacted morulae that were identified at 126 and 138 hours post insemination were 30.9 +/- 6.8 and 31.6 +/- 7.7, respectively. These results indicate that developmentally capable bovine embryos reach the 2-cell stage at 36 hours post insemination, and that they become compacted at the 32-cell stage, which usually occurs between 126 and 138 hours post insemination.

Birth of double-muscled Belgian Blue calves after transfer of in vitro produced embryos into dairy cattle

The possible application of the bovine in vitro fertilization technique for economical beef production was evaluated by transferring in vitro produced Belgian Blue embryos to synchronized dairy cows and heifers. In total, 4167 oocytes, collected in the slaughterhouse from double-muscled Belgian Blue cows, were matured in vitro. Frozen-thawed semen from 3 Belgian Blue bulls was used for in vitro fertilization. Zygotes were cultured in B(2) + 10% estrous cow serum together with oviductal cells at 39 degrees C in 5% CO(2) in air. After 7 days, 576 (13.8%) transferable embryos were obtained. One hundred and eighteen of the most advanced embryos were selected for fresh transfer into 90 recipients. Some of the remaining embryos were frozen using conventional methods. After fresh transfer, 50 recipients (55.6%) had elevated progesterone at day 23. Thirty cows (33.3%) calved after a mean gestation length of 282.8+/-6.0 days and produced 25 single births and 5 twins. The sex ratio was 71.4%. The mean birth weight was 45.1+/-8.3 kg. Three calves were of the conventional type instead of double-muscled and 2 calves died of congenital malformations. After transfer of in vitro produced frozen-thawed Belgian Blue embryos into 27 recipients (1 embryo/recipient), 2 bull calves (7.4%) were born. Bovine embryo production by in vitro techniques could form a low-cost supply of beef calves. However, to render it commercially attractive, selection of sires and dams has to be performed with great care.

A comparative study of the effect of one-step addition of different vitrification solutions on in vitro survival of vitrified bovine embryos

Three experiments were conducted to study the effect of vitrifying in vivo-produced bovine embryos using one-step addition of different vitrification solutions. In Experiment 1, 23 compact morulae to early blastocyst stage embryos were vitrified using a solution consisting of DMSO (2.6 M), acetamide (2.6 M), propylene glycol (1.3 M), and polyethylene glycol (7.5 mM). Only 1 embryo expanded after a 30-second exposure period. In Experiment 2, 11 compact morulae to early blastocysts were exposed for 2 minutes to a vitrification solution containing glycerol (3.4 M) and propylene glycol (3.4 M). None of the embryos survived after vitrification and post-thaw in vitro culture. Dilution of the cryoprotectants in experiments 1 and 2 were carried out in 1 M sucrose for 10 minutes. In Experiment 3, 20 compact morulae-early blastocysts were vitrified after 3 minutes of exposure to a vitrification solution consisting of 7.15 M ethylene glycol, 2.5 mM ficoll and 0.3 M sucrose prepared in embryo transfer freezing medium. As recommended for mouse and rabbit embryos, the cryoprotectant in Experiment 3 was diluted in 0.5 M sucrose. Fifteen compact morulae-early blastocysts expanded or hatched after 48 hours post-thaw in the in vitro culture. It is concluded that ethylene glycol is less toxic following one-step addition of vitrification solution to in vivo-produced bovine compact morulae-early blastocysts than the other vitrification solutions tested. A low concentration of sucrose for dilution of ethylene glycol was also found to reduce the chance of possible osmotic injuries due to dehydration.

TRASTUZUMAB TREATMENT OF EARLY STAGE BREAST CANCER IS COST-EFFECTIVE FROM THE PERSPECTIVE OF THE BELGIAN HEALTH CARE AUTHORITIES

Abstract Trastuzumab (Herceptin®, Roche) is a recombinant, humanized monoclonal antibody directed against the neu-HER2 protein, since May 2002 reimbursed in Belgium for the treatment of metastatic HER2+ breast cancer and since June 2007 also in adjuvant therapy of HER2+ early stage breast cancer. The purpose of this study was to estimate the cost-effectiveness from the Belgian health care payer perspective of reimbursing trastuzumab in the latter indication. A Markov state transition model was designed to adequately capture the natural history and course of disease for early stage breast cancer patients, and to simulate cost and disease progression over a life time perspective. The model estimates differences in outcomes for patients treated with adjuvant trastuzumab during 1 year compared to current therapy, and captures cost consequences and health benefits of trastuzumab treatment. Health benefits were expressed in terms of quality-adjusted life years gained, and future benefits were discounted at 1.5%. Costs were calculated from the perspective of the Belgian authorities’ health care budget, and future costs were discounted at 3%. Where relevant, the costs per Markov state were obtained from the IMS Hospital Disease database. Additionally, an expert opinion analysis on resource use during the follow-up of treated early breast cancer patients provided the cost estimates for states with minor or without hospital costs. The incremental cost-effectiveness ratio based on a life time simulation was estimated at € 10,315 per quality-adjusted life year gained. It can be concluded that trastuzumab treatment of HER2+ early stage breast cancer patients is cost-effective from the perspective of the Belgian health care authorities.

Prevalence of herds with young sows seropositive to pseudorabies (Aujeszky's disease) in northern Belgium

In Belgium, pseudorabies in swine has been the subject of a mandatory eradication programme since 1993. From December 1995 to February 1996, a survey was conducted in the five provinces of northern Belgium to estimate the provincial pseudorabies virus (PRV) herd seroprevalence. Seven hundred and twenty randomly selected herds were included in this survey. To detect recently infected animals, only young sows were sampled. The results show that 44% of these herds had an important number of PRV-seropositive young sows. The highest herd seroprevalence was observed in West Flanders (68%), followed by Antwerp (60%), East Flanders (43%), Limburg (18%), and Flemish Brabant (8%). Assuming a diagnostic test sensitivity and specificity of 95% and 99%, respectively, and a true PRV within-herd prevalence of 43%, the overall true PRV herd prevalence was estimated to be 35%. A logistic multiple-regression revealed that the presence of finishing pigs was associated with a two-fold increase in odds of a herd being seropositive (odds ratio (OR)=2.07, 95% confidence interval (CI) = 1.31-3.26); a breeding herd size > or =70 sows was associated with a four-fold increase in odds of a herd being seropositive (OR = 4.09, 95% CI = 2.18-7.67); a pig density in the municipality of >455 pigs/km2 was associated with a 10-fold increase in odds of a herd being seropositive (OR = 9.68, 95% CI = 5.17-18.12). No association was detected between the PRV herd seroprevalence and purchase policy of breeding pigs (purchased gilts, or use of homebred gilts only).

Salvage of oocytes from sterile genetically valuable cows, resulting in the birth of a calf

The objective of this study was to determine the possible application of in vitro fertilization techniques for calf production in incurable sterility patients or in involuntary cull cows. Ten sterile or fatally injured dams of high genetic value were submitted to in vitro fertilization procedures. Ovaries were recovered after slaughter in eight animals or after ovariectomy in two cows. A total of 261 oocytes were obtained and matured in vitro. Frozen-thawed sperm from eight different bulls of high breeding value (selected to match with one particular cow) was separated with Percoll and used for in vitro fertilization in the presence of heparin. Seventy four embryos started to cleave and 7 days post-insemination, 13 transferable embryos were obtained. Eleven embryos were transferred fresh into nine recipients and produced two pregnancies. One pregnant recipient died of hydro-allantois, the other delivered a live bull calf 288 days after in vitro fertilization.

Estimating the comparative clinical and economic consequences of tulathromycin for treatment of present or anticipated outbreaks of bovine respiratory disease in feedlot cattle in the United States1

The goal of this study was to determine the clinical and economic impact of using tulathromycin as first line treatment for bovine respiratory disease (BRD) compared with other commonly used antimicrobials. Two decision trees were developed simulating the consequences of treating cattle at high risk of developing BRD [control model (CM)] or cattle with first clinical BRD episode [treatment model (TM)]. As comparators florfenicol and tilmicosin were considered in both models whereas enrofloxacin was included in the TM because it was only labeled for treatment of BRD at the time of development of the calculators. A total of 5 (CM) and 10 (TM) comparative clinical studies that reported efficacy data for the selected drugs and indications were identified as suitable for model population. The following outcomes were considered: first treatment success, number of subsequent BRD treatments, chronics, and mortalities. Cost parameters were considered from the perspective of the producer and included treatment costs (first treatment and retreatments) and costs of chronics and deaths derived from published sources for 2010 (default). The models allowed the estimation of clinical and economic consequences according to each individual trial outcomes. Treatment with tulathromycin resulted in more first treatment successes and fewer removals (chronics and deaths) in all comparisons. The average total number of antimicrobial treatments required for the management of BRD was also least with tulathromycin as first treatment option. Because of better efficacy, total costs over the entire study periods were always lowest with tulathromycin. Depending on the study selected as the basis for the efficacy evaluation, cost savings with tulathromycin were calculated in the CM between US

The effect of immunization against gonadotropin-releasing factor on growth performance, carcass characteristics and boar taint relevant to pig producers and the pork packing industry: A meta-analysis

21.00 and

Cost-Effectiveness analysis of Quadrivalent Versus trivalent Influenza Vaccination In Germany — Linking a Dynamic Transmission Model with Health and Economic Outcomes

47.86 (vs. florfenicol) and

VA1 ARE THE BENEFITS OF FLU VACCINATION IN THE ELDERLY CORRECTLY SIMULATED IN ECONOMIC ASSESSMENT MODELS

11.37 and