Functional dissection of Odorant binding protein genes in Drosophila melanogaster.

Most organisms rely on olfaction for survival and reproduction. The olfactory system of Drosophila melanogaster is one of the best characterized chemosensory systems and serves as a prototype for understanding insect olfaction. Olfaction in Drosophila is mediated by multigene families of odorant receptors and odorant binding proteins (OBPs). Although molecular response profiles of odorant receptors have been well documented, the contributions of OBPs to olfactory behavior remain largely unknown. Here, we used RNAi-mediated suppression of Obp gene expression and measurements of behavioral responses to 16 ecologically relevant odorants to systematically dissect the functions of 17 OBPs. We quantified the effectiveness of RNAi-mediated suppression by quantitative real-time polymerase chain reaction and used a proteomic liquid chromatography and tandem mass spectrometry procedure to show target-specific suppression of OBPs expressed in the antennae. Flies in which expression of a specific OBP is suppressed often show altered behavioral responses to more than one, but not all, odorants, in a sex-dependent manner. Similarly, responses to a specific odorant are frequently affected by suppression of expression of multiple, but not all, OBPs. These results show that OBPs are essential for mediating olfactory behavioral responses and suggest that OBP-dependent odorant recognition is combinatorial.

Nightmares, life events and behaviour problems in preschool children.

A postal survey was carried out to identify nursery school children with frequent nightmares in an English city. Of the 22 children reported as suffering from frequent nightmares, 14 came from families who were willing to be interviewed further. A control group with no nightmares, matched for age and sex, was selected from the returns. The mothers of the children in the two groups were interviewed using the Preschool Behaviour Checklist and a life events scale. The results showed that neither life events nor behaviour problems were more prevalent in the frequent nightmares group.

A social skills group for autistic children.

The evolution and preliminary evaluation of a social skills training group for 10 autistic children aged between 9 and 16 years was described. These children attended a special unit which aimed to integrate them into normal school provision. The paper consists of a description of the evolution of the group and the training methods employed and an evaluation of the effect of the group. This was accomplished by the use of a standard teacher's questionnaire. The results of the evaluation are described and the implications for further study of this means of helping autistic individuals discussed.

Gastro-oesophageal pressure gradient changes produced by induction of anaesthesia and suxamethonium.

The pressures in the lower oesophageal sphincter (high pressure zone or HPZ) and stomach were measured in 15 patients with duodenal ulcer and 14 patients with no gastrointestinal disease. All the patients were premedicated with morphine 10 mg i.m. In the patients without duodenal ulcer, the pressure gradient between HPZ and stomach was 6.6 +/- 0.62 mm Hg (mean +/- SEM) before diminishing to 4.9 +/- 0.86 after induction of anaesthesia with thiopentone. During fasciculations following i.v. suxamethonium, the gradient increased to 7.1 +/- 1.0 mm Hg. In patients with duodenal ulcer, although the absolute pressures were less, the gradients during the study were similar to those in healthy patients. We conclude that there is no increased risk of regurgitation during fasciculations induced by suxamethonium.

A comparison of the effect of three anaesthetic techniques on postoperative arterial oxygenation in the elderly.

Ninety patients (age range 49--99 yr) with a fracture of the neck of the femur were anaesthetized by a technique using halothane in oxygen in a closed circuit, halothane and 66% nitrous oxide in oxygen in a Magill circuit or artificial ventilation with 66% nitrous oxide in oxygen ("IPPV group"). In all three groups, there was a small decrease in PaO2 from an overall mean of 9.07 kPa before operation to 8.13 kPa at 60 min after anaesthesia. There was no significant difference between the groups in respect of the decrease; it was concluded that closed-circuit halothane in oxygen anaesthesia for this type of surgery was not accompanied by a significant degree of absorption collapse.