Allocation of attentional resources during habituation to food cues

Two experiments were designed to test the hypothesis that habituation to repeated food cues can be inhibited by allocating processing resources to nonfood cues. In two experiments, the salivary response to 10 presentations of lemon yogurt was assessed while subjects engaged in a controlled cognitive search task (demanding attentional resources), an automatic search task (needing fewer attentional resources), or no task. In Experiment 1, the controlled and automatic search tasks differed in the number of memory set items. In Experiment 2, the size of the memory sets was held constant, and individuals were provided practice to stabilize the different search strategies in the task. The automatic search and no task groups habituated to the repeated presentation of food cues in both experiments, but the controlled search group did not. These results support the hypothesis that allocation of attentional resources to external cues can influence the processing of food cues.     

Effect of fentanyl on the circulatory responses to orotracheal fibreoptic intubation

The effectiveness of fentanyl in attenuating the pressor and heart rate response to orotracheal fibreoptic intubation under general anaesthesia was assessed in 60 healthy patients undergoing elective surgery. Patients were randomly assigned to receive either fibreoptic intubation with or without fentanyl 6 micrograms.kg-1 or traditional Macintosh intubation with fentanyl 6 micrograms.kg-1. A standardised general anaesthetic was administered which included temazepam premedication, thiopentone, atracurium, oxygen, nitrous oxide and isoflurane. The pressor response to fibreoptic intubation was suppressed in those patients who received fentanyl and was similar to that seen in the Macintosh-fentanyl group of patients. The heart rate response to fibreoptic intubation was also significantly reduced in the patients who received fentanyl, but, in contrast, was still significantly greater than that in the Macintosh-fentanyl group. Fentanyl 6 micrograms.kg-1 appears to have a useful place in attenuating the cardiovascular effects of fibreoptic intubation under general anaesthesia.     

Cardiovascular responses to insertion of the laryngeal mask

We have compared, in 40 healthy patients, the cardiovascular responses induced by laryngoscopy and intubation with those produced by insertion of a laryngeal mask. Anaesthesia was induced with thiopentone and maintained with enflurane and nitrous oxide in oxygen; vecuronium was used for muscle relaxation. Arterial pressure was measured with a Finapres monitor. The mean maximum increase in systolic arterial pressure after laryngoscopy and tracheal intubation was 51.3% compared with 22.9% for laryngeal mask insertion (p less than 0.01). Increases in maximum heart rate were similar, (26.6% v 25.7%) although heart rate remained elevated for longer after tracheal intubation. We conclude that insertion of the laryngeal mask airway is accompanied by smaller cardiovascular responses than those after laryngoscopy and intubation and that its use may be indicated in those patients in whom a marked pressor response would be deleterious.     

PLASMA IMMUNOREACTIVE GHRH AND SERUM GH CONCENTRATIONS FOLLOWING PULSATILE GHRH 1-40 ADMINISTRATION IN GH DEFICIENT CHILDREN

We have studied the clearance from plasma of immunoreactive growth hormone releasing hormone 1-40 (IR-GHRH) following intravenous (i.v.) and subcutaneous (s.c.) administration and the relationship between exogenous plasma IR-GHRH concentrations and GH secretion in five GH insufficient children receiving long term nocturnal pulsatile GHRH 1-40. The i.v. studies with GHRH 1-40 1 micrograms/kg demonstrated a distribution half life (t1/2) of 3.9 (SD 0.9) min and an elimination t1/2 of 53.1 (SD 3.2) min. In the s.c. studies the elimination phase was similar to the i.v. results but the transit time to the GHRH peak was slower than the i.v. distribution t1/2 9.9 (SD 3.6) min. These characteristics were maintained during successive pulses of subcutaneous GHRH. The mean IR-GHRH peaks following s.c. GHRH 1-40 administration of 1 microgram/kg and 2 micrograms/kg were 37- and 18-fold lower respectively than the mean IR-GHRH peak observed after the i.v. 1 microgram/kg bolus study. A significant correlation was shown between peak plasma IR-GHRH and serum GH concentrations during the s.c. (r = 0.75) but not the i.v. studies. Pulsatile GHRH administration has been shown to stimulate GH secretion and growth acceleration in GH insufficient children. Knowledge of the relationship between GHRH 1-40 absorption from the subcutaneous site and GH secretion is important for the development of an optimal GHRH treatment regimen in GH insufficient children.     

Screening for visual perceptual deficits following closed head injury a short form of the Visual Form Discrimination Test

The purpose of this study was to evaluate the concurrent validity and clinical utility of a short form of the Visual Form Discrimination Test in persons with closed head injuries n 62 Given the homo geneity of the items and patients apparent consistency in responding we hypothesized that scores from an eight item short form would be highly similar to the scores derived from the full version of the test i e 16 items The mean difference between the short form and full version was less than one point and the correlation between the two forms was 0 86 Applying a clinical decision rule resulted in a normal impaired overall correct classification rate of 98 4 The short form shows considerable promise as a brief test of visual discrimination in persons with closed head injuries     

The prognostic value of facial electroneurography in Bell's palsy

Twenty six patients with Bell's palsy were studied at presentation using electroneurography. Ninety-four per cent of those who recovered completely could have been predicted by ENoG within 10 days of onset. Of the 18 patients who recovered completely, 13 had a total palsy at presentation.     

Gene expression of LDL receptor, HMG-CoA reductase, and cholesterol-7 alpha-hydroxylase in chronic renal failure

BACKGROUND: Chronic renal failure (CRF) is associated with an atherogenic lipid profile and an increased risk of ischaemic cardiovascular disease. The associated hyperlipidaemia is reportedly ameliorated by erythropoietin (Epo) therapy. According to a recent report, rats studied 3 weeks after 5/6 nephrectomy and fed a high- protein diet exhibited increased activities of hepatic HMG-CoA reductase (HMG-CoAR) and cholesterol 7 alpha-hydroxylase (Ch-7 alpha- H), despite normal corresponding mRNA values. DESIGN AND METHODS: This study was designed to examine the effects of naturally progressing CRF of longer duration as well as those of Epo therapy on gene expressions of the key factors involved in hepatic cholesterol metabolism, i.e., LDL receptor (LDLR), HMG-CoAR, and Ch-7 alpha-H. Sprague-Dawley rats were randomized to the CRF group (5/6 nephrectomy), Epo-treated CRF group (given Epo 150 U/kg/twice weekly) and sham-operated, placebo- treated normal controls. They were allowed free access to regular rat chow and studied 6 weeks after surgery. Liver mRNAs and protein mass or activities of the above factors were studied. RESULTS: Plasma cholesterol concentration was significantly increased in the CRF group (P < 0.001) and was modestly lowered (P < 0.05) by Epo therapy. However, microsomal cholesterol concentration and LDLR, HMG-CoAR, and Ch-7 alpha-H mRNA as well as HMG-CoAR activity, and Ch-7 alpha-H and LDLR protein mass measurements were virtually identical in the three groups. Thus, hepatic LDLR, HMG-CoAR, and Ch-7 alpha-H mRNA and protein measurements in rats with CRF were similar to those of the normal control group representing an inappropriate response to the associated hypercholesterolemia. Epo therapy led to partial amelioration of CRF- associated hypercholesterolaemia with no discernible effect on hepatic tissue expression of the above factors.