Postoperative bradycardia is not uncommon following the Fontan procedure in patients with a functional single ventricle. The surgical connections created with various Fontan modifications may complicate access to the atria for transvenous implantation of a permanent pacemaker. We describe approaches to overcoming problems with atrial access in an adolescent with complex congenital heart disease who required permanent transvenous atrial pacing for tachycardia-bradycardia after Fontan surgery.

Adolescent↗

PubMedDate not supplied

An assessment of the pharmacokinetics and pharmacodynamics of single doses of amlodipine in elderly normotensives.

This study characterizes the single dose pharmacokinetic characteristics of the dihydropyridine calcium antagonist drug amlodipine in a group of 16 elderly subjects, aged 65 to 86 years (8 M:8 F). The most notable pharmacokinetic features were a prolonged terminal elimination half life of 48 +/- 16 hours and a delayed tmax of 7.3 +/- 1.3 hours. Consistent with the time to achieve peak plasma drug concentrations, there was a modest but significant reduction in blood pressure at 6-8 hours after dosing. Comparison of these results with those of published data for young subjects indicate not only a greater degree of intersubject variability but also a longer half life in the elderly, suggestive of reduced drug clearance, which may lead to higher plasma drug concentrations particularly at steady state.

Aged↗

PubMedDate not supplied

Seroprevalence of five arboviruses in Zebu cattle in the Central African Republic.

Sequential blood samples taken from 237 adult and 147 young Zebu cattle in the Central African Republic (CAR) were examined by enzyme-linked immunosorbent assay for the presence of antibodies to Rift Valley Fever (RVF), Dugbe (DUG), Crimean-Congo haemorrhagic fever (CCHF), Chikungunya (CHIK) and Wesselsbron (WSL) viruses. Antibodies to DUG and CCHF viruses were detected in 70% and 61% respectively, of the sera from adult cattle, probably due to common antigens. This hypothesis is supported by the fact that CCHF virus was isolated only 3 times from ticks, whereas DUG virus was isolated from almost all ticks. Ticks of the genus Hyalorama, the most important vectors of CCHF, are rare on Zebus in CAR. CCHF virus has a limited role in local human pathology, probably because its distribution is limited by the scarcity of its main vector and the immunological barrier resulting from the presence of antibodies to DUG virus. Antibodies to RVF virus were found in about 8% of adult cattle. Zebus do not play an important role in the spread of CHIK and WSL viruses among humans; these viruses were found in only one and 5, respectively, of the 183 cattle examined.

Animals↗

PubMedDate not supplied

Immunological relationships between rabies virus and rabies-related viruses studied with monoclonal antibodies to Mokola virus.

Specific monoclonal antibodies (mAb) were prepared against a rabies-related lyssavirus, Mokola virus. A strain isolated in the Central African Republic, Mok-3, was used as immunogen. After 3 fusions more than 90 hybridoma cultures secreting mAb were identified. According to their different patterns of reactivity against rabies and rabies-related viruses, 61 ascites fluids were obtained. The antibody class was IgM for 2 of them and IgG for 59. They were specific for one of the 4 major viral proteins, as determined by immunofluorescence, neutralization and immunoblotting tests. Their patterns of reactivity were determined against 6 different strains of rabies-related viruses: Lagos-bat virus from Nigeria (Lag-1) and the Central African Republic (Lag-2), Duvenhage virus from the Republic of South Africa (Duv-1) and Federal Republic of Germany (Duv-3), Mokola virus from Nigeria (Mok-1) and Cameroon (Mok-2) and a fixed strain of rabies virus, the challenge virus strain (CVS). According to their reactivities with these strains and the pattern of fluorescence, the mAb were classified into 11 different groups with intracytoplasmic fluorescence and 7 groups with cell surface fluorescence. A differential diagnosis of these lyssaviruses is possible in tissue culture using some of these mAb.

Animals↗

PubMedDate not supplied

Emergence of tics in children with attention deficit hyperactivity disorder treated with stimulant medications.

The emergence of tics in children treated with stimulant medication for attention deficit hyperactivity disorder (ADHD) was investigated. A retrospective chart review of the medical records of 555 subjects was performed to examine the emergence of tics in relation to treatment with a stimulant medication, dosage, duration of treatment, and age of subjects. A total of 7.8% of the subjects treated with stimulants developed tics: 8.3% of subjects treated with methylphenidate, 6.3% with dextroamphetamine, and 7.7% with pemoline. The subjects who developed tics were significantly younger than those who did not. Subjects treated with higher doses of stimulant medication were not more likely to develop tics. While the emergence of tics was common, these subjects may have developed tics irrespective of stimulant medication. Controversy remains as to the long-term risk of tics in relation to stimulant medication and to appropriate practice should tics emerge during the course of stimulant medication treatment.

Attention Deficit Disorder with Hyperactivity↗