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Biomedical subjects

J O Robinson

Publications and source records attributed to J O Robinson.

At least 19 recordsLinked to original sources
PubMed2005

[Utility of procalcitonin for the diagnosis and the follow-up of infections in febrile neutropenic patients].

Procalcitonin is a marker of severe bacterial infections in non-neutropenic patients. The goal of this review is to assess its utility in the management of neutropenic patients. A delayed treatment of infection in this setting results in severe morbidity and high mortality. As traditional diagnostic tools often fail to exclude infection when fever occurs, all these patients receive empirical antimicrobial therapies during long periods of time. Present knowledge suggests that procalcitonin may contribute to identify patients in whom 1) antibiotics could be stopped in the absence of bacterial infection, 2) investigations and adjustments of the antimicrobial therapy for persistent fever are needed. The use of procalcitonin for the management of febrile neutropenic patients should be studied prospectively.

Anti-Bacterial Agents↗
PubMed2000

Form and movement in stereokinetic cycloids: motion lost and found.

In exploring stereokinesis, we devised flat cycloidal display figures which, when rotated on a disc in the frontal plane, are perceived as illusory three-dimensional forms with movement in depth; the dominant percepts were of twisted loops with an internal writhing motion. These dominant forms could be convincingly represented by stereo pairs derived from the flat display; related forms, not seen in the illusion, could also be constructed, seeming to show a selectivity for preferred stereokinetic forms by the perceptual system. Models were made of the stereo forms; when rotated, they showed similar illusions and selectivity. We suggest that the illusions arise because some components of the real motion do not appear in the sensory field. The perceptual system accommodates for this by constructing percepts which are not necessarily veridical but do reconcile form and motion into a coherent unity. The results are discussed in relation to concepts of invariance and rigidity, and with regard to the creative response to sensory data by the perceptual system.

Computer Graphics↗
PubMed1997

Elements for a report card: one institution's experience moving from theory to trial.

The emerging computerized patient record, the movement toward a unified nursing language, and increasing accountability to the public for clinical outcomes are converging forces that require a coherent plan if nursing is to evaluate outcomes. The article describes a nursing service and school of nursing's approach and beginning experiences in identifying concepts and indicators that are useful to clinicians. These concepts and indicators have the potential to be embedded in a concurrent information system that would feed a data repository used retrospectively by clinicians and researchers. The article also discusses results to date and lessons learned.

Databases, Factual↗
PubMed1996

Stereokinetic interaction effects involving static and slowly moving identical figures.

Here a new depth effect evoked by the spatial and temporal interaction in 2-D of a slowly moving circle (optimally at 0.6 rads/sec) with an identical static circle is reported. Typically, respondents report that with increasing adjacency, commencing with separations of a few diameters, the moving circle appears in a different plane of depth to the static circle, it then usually appears to "dip" onto the static circle and after complete coincidence with it to rise away from it. This effect, together with a number of associated descriptions are commented upon, in addition to observations when viewing overlapped static circles and overlapped circles in motion, this latter stimulus condition evoking the stereokinetic effect. The authors have previously suggested that contour "sliding," which simulates motion parallax, is the key to understanding stereokinesis. The stimulus conditions giving rise to this new effect directly simulate the motion parallax information present in a retinal image.

Adolescent↗
PubMed1994

The subjective effects of low-dose propofol. A double-blind study to evaluate dimensions of sedation and consciousness with low-dose propofol.

In this study the subjective effects (sedation and mood) of subanaesthetic doses of propofol were examined in 28 healthy male volunteers. A computer model was used to predict the infusion profiles necessary to obtain steady state propofol plasma concentrations of 0.3 microgram.ml-1, 0.6 microgram.ml-1, 0.9 microgram.ml-1. Objective measures of sedation from saccadic eye movement and choice reaction time gave significant dose responses at each level but a battery of psychometric tests failed to show dose-related subjective responses. Of particular note in the subjective data is the lack of a difference between groups or even of a consistent trend within the data. This suggests that a low concentration of propofol in plasma does not induce euphoria or a sense of well-being. The anecdotal evidence available for mood changes with propofol therefore remains unsubstantiated.

Adult↗
PubMed1993

Interaction of H2-receptor antagonists and benzodiazepine sedation. A double-blind placebo-controlled investigation of the effects of cimetidine and ranitidine on recovery after intravenous midazolam.

H2-receptor antagonists differentially inhibit cytochrome P450 and this may affect the rate at which benzodiazepines are metabolised. However, it is not known whether this delayed clearance results in prolonged psychomotor impairment. In a randomised double-blind trial 28 healthy volunteers received two single doses of midazolam (0.07 mg.kg-1) at an interval of one week during which they took cimetidine 400 mg, ranitidine 150 mg or placebo, each twice daily. Recovery from the benzodiazepine was monitored on each occasion over a 12 h period using a battery of psychometric tests. There was wide individual variation in performance; however, an overall measure of impairment indicated a significant difference at 2.5 h (p < 0.05), the cimetidine group having a high impairment score. This decrement appeared to be in cognitive and psychomotor functions and was not reflected in the subjective assessment.

Adolescent↗
PubMed1991

Reversal of benzodiazepine sedation with the antagonist flumazenil.

The effectiveness of the benzodiazepine antagonist, flumazenil, was evaluated in a randomized double-blind clinical study in which diazepam 0.2 mg kg-1 or midazolam 0.1 mg kg-1 was used for i.v. sedation. We studied 120 day-case patients undergoing gastroscopy and treated with either flumazenil 0.1-2 mg or placebo after the procedure. Psychometric assessment of four aspects of recovery over a 3-h period showed that flumazenil attenuated the sedative effects of the benzodiazepines, but did not antagonize the sedation completely. For patients sedated with diazepam, there was a significant effect of flumazenil on speed of motor co-ordination after 90 min (P less than 0.01), and for those given midazolam a similar effect was found at 20 min (P less than 0.01). However, after 3 h all four groups of patients had not returned to baseline performance in accuracy of motor co-ordination (P less than 0.01) and cortical arousal (P less than 0.05), and the two groups sedated with diazepam still displayed memory deficits (P less than 0.05). Flumazenil did not attenuate the subjective experience of sedation as measured by visual analogue scales. These results indicate that sedation is multidimensional, differentially affecting the hierarchy of cognitive functions. In day-cases, antagonism of benzodiazepine sedation with flumazenil would not hasten the safe discharge of patients.

Adolescent↗
PubMed1991

Propofol in short gynaecological procedures. Comparison of recovery over 2 days after anaesthesia with propofol or thiopentone as sole anaesthetic agent.

Recovery was assessed over 48 hours after anaesthesia with propofol or thiopentone as sole anaesthetic agent in 36 unpremedicated gynaecological patients. Immediate recovery, as measured by the Steward scale, was shown to be quicker for the patients given propofol. At one hour postoperatively the thiopentone group showed impaired visual-motor coordination on the aiming test (p less than 0.01) and dexterity task (p less than 0.05), and a slowing of reaction time (p less than 0.01). Patients given propofol showed only an increase in reaction time (p less than 0.05). By 2 hours the thiopentone group showed impairment only in the aiming task (p less than 0.05). No further significant impairment was detected at 4, 24 or 48 hours. However, patients reported symptoms throughout the 48 hours indicative of residual drug effects. There was a substantial practice effect with some tests which may have obscured impairment. It can be argued therefore that the better recovery profile after propofol is still evident at 24 hours.

Adolescent↗
PubMed1991

Longitudinal studies of virulence factors of Pseudomonas aeruginosa in cystic fibrosis.

Among 111 strains of Pseudomonas aeruginosa from 49 children with cystic fibrosis, duration of colonization correlated with bacterial phenotype. We confirmed that P. aeruginosa from chronically colonized patients tended to be less motile, produce lower levels of protease and elastase, to be more sensitive to normal serum and to be polyagglutinating or untypable with standard antisera. We also showed that phospholipase and heat-stable hemolysin, concerned in metabolism of inorganic phosphate, and exotoxin A, were lower in these isolates. In longitudinal studies there was a decrease in virulence properties when isolates from the same patient were compared. No reversion from altered phenotype to 'wild-type' characteristics was found.

ADP Ribose Transferases↗
PubMed1991

A survey of concurrent drug therapy among day unit patients.

In order to assess the reliability of drug information supplied by day-stay cases, 85 consecutive patients were interviewed. A comparison of the interview answers with the details previously volunteered during the admission procedure showed an increase of 80% in the information given by the patient. While the detailed interviewing technique is time-consuming and may not be infallible, this substantial increase in information highlights problems in the current routine.

Adolescent↗
PubMed1990

Life events and family history in children with recurrent abdominal pain.

Children suffering from recurrent abdominal pain (RAP) were compared with matched controls on measures of illness behaviour, parents' illness behaviour, early parent-child relationships and stressful life events. Relatively, the RAP children stayed away from school more, needed more attention when ill, tended to show more anxiety in various ways, had parents who reported more symptoms, and had suffered a greater number of stressful experiences in the few months before pain onset.

Abdominal Pain↗
PubMed1989

Comparison of diazepam with midazolam as i.v. sedation for outpatient gastroscopy.

We studied 26 patients in a double-blind investigation to compare psychomotor and cognitive recovery for 30 h after sedation for day-case gastroscopy with i.v. diazepam 0.15 mg kg-1 or midazolam 0.07 mg kg-1. Significantly more patients reported side effects at 7, 10 and 30 h post-gastroscopy after diazepam than after midazolam (P less than 0.05). Compared with baseline, the midazolam group was significantly impaired in critical flicker fusion threshold, reaction time, dexterity and visualization tasks up to 4 h after administration (P less than 0.05). There was a significant association between midazolam and amnesia for the procedure (P less than 0.001).

Adult↗
PubMed1989

Propofol-induced anaesthesia. Double-blind comparison of recovery after anaesthesia induced by propofol or thiopentone.

Postoperative psychomotor and cognitive recovery were assessed after anaesthesia induced by either propofol or thiopentone, and maintained with nitrous oxide and halothane in 40 unpremedicated dental patients. Performance was shown to be impaired one hour postoperatively for the whole sample in hand-eye coordination (p less than 0.001), reaction time (p less than 0.001) and digit span (p less than 0.05). There was evidence of impairment at 3 hours postoperatively in reaction time (p less than 0.05) and ataxia (p less than 0.01). Performance also deteriorated in the dexterity and aiming tasks. Patients reported significantly less clumsiness by 24 hours in blurred vision and shivering (p less than 0.05) and by 48 hours less coughing (p less than 0.05). However, there was no significant difference between groups. No evidence showed that recovery in the propofol group was faster, so it was concluded that induction with propofol offered no advantage when anaesthesia is maintained with nitrous oxide and halothane for the periods of time reported in this study.

Adolescent↗
PubMed1988

A double-blind comparison between nitrazepam, lorazepam, lormetazepam and placebo as preoperative night sedatives.

Benzodiazepines are used as hypnotics to reduce anxiety and give a good night's sleep on the night prior to surgery. In a double-blind procedure, patients were given either lorazepam (2 mg or 4 mg), lormetazepam (1 mg or 2 mg), nitrazepam 10 mg or placebo. Measures were taken of sleep, anxiety, memory and after-effects. There was no evidence that the drugs reduced anxiety, nor evidence of amnesia. Quality and length of sleep was shown to be better for nitrazepam (P less than 0.05), lorazepam 2 mg (P less than 0.05) and lorazepam 4 mg (P less than 0.01), compared with placebo. However, significantly higher ratings of clumsiness and confusion as after-effects were found with nitrazepam (P less than 0.05), and clumsiness (P less than 0.005), slurred speech and blurred vision (P less than 0.01), sleepiness, nausea, weakness and confusion (P less than 0.05) with lorazepam 4 mg. It was concluded that lorazepam 2 mg produced the greatest net benefit.

Adult↗
PubMed1986

Treatment of breast cancer through the ages.

Considerable controversy still exists regarding the correct management of cancer of the breast. This short history follows the paths of thought and practice from the Egyptian dynasties to modern times. A description is given of the pathologic reasons for the variance in local treatment and the development of adjuvant therapy.

Breast Neoplasms↗
PubMed1986

The frequent consulter in primary medical care.

A comparison is reported between a group of frequent consulters of general medical practitioners and a group of infrequent consulters. The frequent consulters reported more symptoms, particularly upper respiratory, gastro-intestinal and back troubles. They took more proprietory medicines and more vitamin pills and were less inclined to ignore symptoms. They were more inclined to negative mood. Although they had slightly fewer stressful life events they coped less well with them, perhaps because they had less satisfactory family and social support and found less distraction in social activities. By means of a model the symptoms of these subjects are contrasted with symptoms found in psychosomatic disorder.

Adult↗