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P Pearson

Publications and source records attributed to P Pearson.

77 records · Page 5Linked to original sources
PubMedDate not supplied

Alcohol does not affect visual contrast gain mechanisms.

It has been suggested that acetylcholine plays a role in contrast discrimination performance and the regulation of visual contrast gain (Smith, 1996). Since alcohol has been shown to reduce levels of acetylcholine and contrast sensitivity, the present study measured the effects of alcohol on contrast discrimination and explored whether the deficits could be explained as a consequence of reduction in contrast gain. Detection thresholds and contrast increment thresholds under placebo and alcohol (0.06% BAC) conditions were measured in six volunteers. Alcohol was found to impair both detection and discrimination of only high spatial frequencies. However, when the base contrasts used in the increment threshold task were equal multiples of detection threshold, no alcohol-induced changes in increment thresholds were obtained at any spatial frequency. We conclude that alcohol impairs contrast discrimination performance but that no change in contrast gain mechanisms need be postulated to account for the data.

Adult↗
PubMedDate not supplied

Frequency selective effects of alcohol on auditory detection and frequency discrimination thresholds.

In the first of two experiments, the effects of ethyl alcohol on monaural and binaural thresholds for pure tones were measured for a range of frequencies. The results showed a frequency-specific effect in which low frequencies were more severely affected than higher ones. Also, monaural thresholds tended to be more affected by alcohol than binaural ones. The second experiment extended this exploration by measuring frequency discrimination at several different frequencies. In this case, we also obtained a frequency-dependent effect: the increase in discrimination thresholds above 1000 Hz was three times greater than that for lower frequencies. The data suggest that the choice of stimuli may influence the ability to detect changes in auditory performance after alcohol and may account in part for the differences among earlier studies. The results are consistent with the hypothesis that alcohol is acting centrally, at the level of mechanisms involved in the temporal and binaural summation of auditory signals, rather than influencing peripheral structures.

Adult↗
PubMedDate not supplied

Doxorubicin cardiotoxicity in children: reduced incidence of cardiac dysfunction associated with continuous-infusion schedules.

We retrospectively reviewed the medical records of 97 children (59 boys and 38 girls) with a median age of 13 +/- 4 years who had been treated with continuous infusion of doxorubicin at a dosage of 60 mg/m2 over 24 h (61 patients) or at a dosage of 75 mg/m2 over 72 h (36 patients). The drug was administered every 3 weeks. The cardiac status of patients was evaluated as a baseline and every 6 months during, and following therapy (median, 30.5 months). The evaluations included M-mode and two-dimensional echocardiography. Congestive heart failure developed in only one patient in this series, an 8-year-old girl who ultimately died of her cardiac complication. This incidence of doxorubicin-induced cardiotoxicity was compared with that seen in a control group of pediatric patients previously treated with doxorubicin at similar dosages but with a rapid infusion. The result compared favorably to the 13% incidence of cardiotoxicity (p = 0.03) and 7% mortality (p < 0.01) in the control group. No changes in the levels of tumor response were noted in children treated by continuous infusion when compared with historical controls. Continuous-infusion schedules of doxorubicin thus result in fewer incidences of cardiotoxicity in children and should be considered for wider application in pediatric cancer patients receiving doxorubicin.

Adolescent↗
PubMedDate not supplied

Sensitivity and care: vital tools for skill-mix review.

The issue of skill mix has become linked in the minds of many nurses with 'skill dilution'. This paper discusses the ideas used in a skill-mix review and looks at the essential differences between skill mix and grade mix. The authors have examined the literature and draw some important lessons, providing pointers for anybody who is charged with, or whose unit is subject to, a skill-mix review.

Community Health Nursing↗