Colostral antibody induced interference of inactivated bluetongue serotype-8 vaccines in calves.

Since its introduction into northern Europe in 2006, bluetongue has become a major threat to animal health. While the efficacy of commercial vaccines has been clearly demonstrated in livestock, little is known regarding the effect of maternal immunity on vaccinal efficacy. Here, we have investigated the duration and amplitude of colostral antibody-induced immunity in calves born to dams vaccinated against bluetongue virus serotype 8 (BTV-8) and the extent of colostral antibody-induced interference of vaccination in these calves. Twenty-two calf-cow pairs were included in this survey. The median age at which calves became seronegative for BTV was 84 and 112 days as assayed by seroneutralisation test (SNT) and VP7 BTV competitive ELISA (cELISA), respectively. At the mean age of 118 days, 13/22 calves were immunized with inactivated BTV-8 vaccine. In most calves vaccination elicited a weak immune response, with seroconversion in only 3/13 calves. The amplitude of the humoral response to vaccination was inversely proportional to the maternal antibody level prior to vaccination. Thus, the lack of response was attributed to the persistence of virus-specific colostral antibodies that interfered with the induction of the immune response. These data suggest that the recommended age for vaccination of calves born to vaccinated dams needs to be adjusted in order to optimize vaccinal efficacy.

[Can children visit their relatives in an adult ICU?]. / Les enfants peuvent-ils venir visiter leurs parents hospitalisés en réanimation oncohématologique?

For the last three years, our oncology ICU (intensive care unit) has been opened to visiting children between 0 and 18 years. Our objective was to attempt to decrease the psychological burden in critically ill cancer patients and their children. We report here the evaluation of this new policy. Encouraged by the child psychologists in our hospital, we first recorded the opinions of the nursing staff, patients and relatives about this innovative approach. As our preliminary findings were favourable, a liberalised greeting and education policy for visiting children was implemented. A dedicated procedure was followed in order to provide children with a better understanding of their parent's disease, to alleviate any traumatic experience the visit might cause and to create an environment where mutual confidence would reign. After 2 years, each visiting child, patient, accompanying parent and the nursing staff were directly questioned using a specifically designed questionnaire. The daily lives of the staff, children, families and patients themselves appeared to be dramatically improved, even in the most difficult medical situations. Based on these promising results, the new policy has definitively been adopted in our unit. We propose that children ought to be allowed to visit a parent in the ICU and that this policy warrants evaluation in other types of units.

Reduced oxidative stress and blood lactic acidosis in trained breath-hold human divers.

We hypothesized that the repetition of brief epochs of hypoxemia in elite human breath-hold divers could induce an adaptation of their metabolic responses, resulting in reduced blood acidosis and oxidative stress. Trained divers who had a 7-10 year experience in breath-hold diving, and were able to sustain apnea up to 440 sec at rest, were compared to control individuals who sustained apnea for 145 sec at the most. The subjects sustained apnea at rest (static apnea), and then, performed two 1-min dynamic forearm exercises whether they breathed (control exercise) or sustained apnea (dynamic apnea). We measured arterial blood gases, venous blood pH, and venous blood concentrations of lactic acid, thiobarbituric acid reactive substances (TBARS), and two endogenous anti-oxidants (reduced glutathione, GSH, and reduced ascorbic acid, RAA). In control subjects, the three experimental conditions elicited an increase in blood lactic acid concentration and an oxidative stress (increased TBARS, decreased GSH and RAA concentrations). In divers, the changes in lactic acid, TBARS, RAA, and GSH concentrations were markedly reduced after static and dynamic apnea, as well as after control exercise. Thus, human subjects involved in a long duration training programme of breath-hold diving have reduced post-apnea as well as post-exercise blood acidosis and oxidative stress, mimicking the responses of diving animals.