Effects of acute administration of d-amphetamine and haloperidol on procedural learning in man

The effects of an indirect dopamine-agonist, d-amphetamine, and a non-selective dopamine receptor antagonist, haloperidol, were investigated in normal male volunteers using a between-subjects double-blind design in a procedural learning task, thought mainly to involve unconscious/automatic learning. The results showed: (1) d-amphetamine facilitated response speed, whereas haloperidol inhibited it, in comparison to placebo; (2) the linear increase in procedural learning corresponded with pharmacological manipulation of degree of dopaminergic activity, i.e. subjects given haloperidol showed the least, and subjects given d-amphetamine the greatest, procedural learning. The implications of these findings are discussed in relation to investigation of abnormalities of procedural learning processes in schizophrenia. Received: 28 June 1996/Final version: 2 October 1996     

Pharmacokinetics of orally administered norethisterone enanthate in rabbit, monkey, and women

Norethisterone enanthate (NET-En), an established intramuscular long-acting contraceptive agent, has previously been shown to be effective in inhibiting fertility in two rodent species even 4 days after oral ingestion. Pharmacokinetics of NET and NET-En were studied after oral and intramuscular doses in two animal species and a few women. The results suggest that the NET-En was absorbed within a day in all the species after oral dose. The estimates of relative bioavailability ranged from 13 to 51% in rabbits, monkeys, and women. The elimination half-life was 5–10 days. The presence of the active component, NET, in the circulation over the experimental period of 15 days suggests that NET-En could be useful as a long-acting oral pill. The suppression of progesterone levels during the luteal phase of menstrual cycle in women also supports this finding.     

Interference of factor V Leiden on protein S activity: evaluation of a new prothrombin time-based assay.

Protein S activity in plasma from factor V Leiden (FVL)-positive patients may be lower than expected. We investigated a new commercially available method for protein S for such interference. Protein S activity was measured for plasmas from 50 individuals with FVL and their results were compared with those obtained for plasmas from 47 sex-matched and age-matched individuals without FVL. We assumed that the median protein S activity value from a relatively large number of individuals with or without FVL would not be significantly different if there is no influence from FVL. The FVL-positive plasmas gave relatively (albeit not significantly) lower protein S levels than FVL-negative plasmas when both were tested undiluted (86 versus 93 IU/dl, P = 0.06). Those differences were reduced (98 versus 102 IU/dl, P = 0.58) when testing was performed on diluted plasmas. Furthermore, the proportion of patients with FVL identified as low-abnormal on the basis of the specific cut-off values (undiluted = 64 U/dl; diluted = 71 IU/dl), which was 8% when testing was performed on undiluted plasmas, was reduced to 4% when testing was performed on diluted plasmas. Conversely, the corresponding proportions of patients without FVL remained unaltered (4.3 versus 4%). In conclusion, these results indicate that the evaluated method is somewhat affected by FVL and that dilution of plasma prior to testing improves specificity. Protein S activity measurement for FVL-positive patients should be performed on diluted plasma and the results interpreted on the basis of the cut-off value specifically determined for diluted plasmas.     

Nucleolin Promotes Homologous DNA Pairing in vitro

We purified to near homogeneity a previously identified 100 kDa mammalian homologous DNA pairing protein. The purified 100 kDa protein also catalyzed high levels of cell-free homologous DNA recombination activity. This ATP-dependent activity was capable of forming conservative recombinant products between two circular, double-stranded DNA molecules. We were unable to detect any DNA polymerase, DNA ligase, or 5' or 3' exonuclease activity associated with this purified material. The purified 100 kDa protein bound silver nitrate as well as a monoclonal antibody specific for nucleolin. A recombinant protein comprised of the Escherichia coli maltos-ebinding protein fused to the carboxyl-terminal two-thirds of human nucleolin possessed homologous DNA pairing activity. These data indicate that the 100 kDa homologous DNA pairing protein is nucleolin. The observation that nucleolin can carry out homologous DNA strand pairing in vitro raises the prospect that it may function similarly in vivo.     

Anaesthesia and the Sturge-Weber syndrome

We report a series of 13 patients with Sturge-Weber syndrome anaesthetised on 17 occasions. Anaesthesia management varied depending on the clinical manifestations which ranged from localized, superficial skin lesions to extensive systemic involvement. These patients tolerate anaesthesia well but anaesthetic management includes evaluation for associated anomalies. Difficulty with intubation may occur due to angiomas of the mouth and upper airway. Anaesthesia should be planned to avoid trauma to the haemangiomata and increases in intraocular and intracranial pressure. Nous rapportons une série d’observations concernant des porteurs du syndrome de Sturge-Weber anesthésiés à 17 occasions. L’anesthésie a varié selon les manifestations cliniques qui allaient de la lésion superficielle localisée à l’atteinte systémique grave. Ces patients tolèrent bien l’anesthésie mais celle-ci nécessite une recherche des anomalies associées pour fin d’évaluation. La présence d’angiomes de la bouche et des voies respiratoires supérieures peut rendre l’intubation difficile. La planification de l’anesthésie doit inclure la prévention du traumatisme aux hémangiomes et de l’augmentation de la tension intraoculaire et cérébrale.     

Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts

Background. Results of aortic arch reconstruction in the setting of biventricular physiology are well documented in the adult population, however, in children, surgical outcome of this subgroup of patients is less clear.

Methods. We studied the clinical outcomes of 37 children aged 8 days to 15 years (median 26 months), who underwent aortic arch reconstruction for arch hypoplasia from 1982 to 1997. The children were divided into three groups: Group 1 (20 patients) had isolated aortic arch lesions, Group 2 (13 patients) had associated intra-cardiac pathology yet conserving a biventricular physiology, Group 3 (4 patients) had Williams Syndrome. Previous interventions for coarctation had been performed in 30 patients (81%). Arch repair consisted of a patch aortoplasty in the majority of patients (35 of 37 children).

Results. Operative mortality occurred in 5 children, 4 in Group 2 (31%), 1 in Group 3 (25%) and none in Group 1. Permanent neurological complications occurred in 2 children (5 %). During the follow-up, which ranged from 1 month to 8 years, balloon angioplasty for arch obstruction was required in 1 child. There was one late death, associated with a subsequent intra-cardiac repair.

Conclusions. Aortic arch surgery in children with isolated arch hypoplasia, is associated with excellent early and late survival in addition to a low reintervention rate. Alternative perfusion and operative strategies must be implemented in infants with associated intra-cardiac anomalies to improve results.