The Effect of Sympathomimetic Medication on Cardiovascular Functioning of Children with Attention-Deficit / Hyperactivity Disorder : Cardiovascular Topic

Objective : The aim of this study was to investigate the effects of sympathomimetic medication on the cardiovascular system of children with attention-deficit / hyperactivity disorder (ADHD). Methods : Cardiovascular functioning of children with ADHD (n = 19) was tested while the children were stimulant free and during a period in which they were on stimulant medication. Electrocardiograms (ECGs) were obtained by means of a Schiller CardioLaptop AT-110 ECG recorder using the standard 12-lead cable positioning for a resting ECG. Blood pressure was measured by means of a stethoscope and mercury sphygmomanometer. Results : The main findings of this study were that methylphenidate usage is associated with increases in heart rate (HR) and blood pressure (BP); and that it does not adversely affect HR-corrected QT and JT intervals or cardiac dispersion values. Conclusion : Methylphenidate causes an increase in HR as well as increases in both systolic and diastolic BP; but no change in cardiac depolarisation and repolarisation duration or homogeneity

Immunity against Babesia rossi infection in dogs vaccinated with antigens from culture supernatants.

Soluble parasite antigens (SPA) from different Babesia species have been shown earlier to induce protective immunity when used as vaccine. However, initial attempts to produce such vaccine against Babesia rossi infection using SPA from B. rossi culture supernatants were not or only partially successful. Here we show that when dogs were vaccinated with a vaccine comprising SPA from B. rossi combined with SPA from Babesia canis protective immunity against experimental challenge infection was induced. Immunity was reflected in reduced clinical signs that resolved spontaneously, and reduction of parasitaemia and SPA in the blood. Not a single infected erythrocyte could be found in blood smears of dogs that had been repeatedly boosted (three vaccinations in total). In contrast, three out of four control dogs required chemotherapeutic treatment to prevent death. The fourth control dog showed a transient parasitaemia that resolved spontaneously. Vaccination did not prevent the development of a transient anaemia. It is concluded that a vaccine containing a mixture of SPA obtained from in vitro culture supernatants of B. rossi and B. canis induces protection in dogs against heterologous challenge infection with B. canis (as shown before) or B. rossi.