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Biomedical subjects

D J Turner

Publications and source records attributed to D J Turner.

15 recordsLinked to original sources
PubMed1991

Bronchial responsiveness and lung function in recurrently wheezy infants.

Although most wheezy infants are considered asthmatic, they generally respond poorly to antiasthma treatment, and there is inadequate knowledge about the pathologic mechanisms that cause wheezing at this age. The aim of this study was to determine whether the strong association between wheezing and bronchial responsiveness (BR) seen in older subjects was also present in infants. We compared BR with inhaled histamine in 19 recurrently wheezy infants with a group of age-, height-, weight-, and sex-matched control infants. Maximal flow at FRC (VmaxFRC) was determined from partial expiratory flow-volume curves generated using the "squeeze" technique. Histamine was delivered during 1 min of tidal breathing in doubling concentrations from 0.125 g/L to a maximum of 8 g/L or until VmaxFRC fell by 40% (PC40). The median baseline VmaxFRC for the wheezy infants was 100.0 ml/s compared with 182.0 ml/s for the control infants (p less than 0.01). However, there was no significant difference in the PC40 between the two groups (2.1 versus 2.3 g/L).

Asthma↗
PubMed1990

Methodological aspects of flow-volume studies in infants.

Although valuable information is being obtained using new techniques to assess infant respiratory mechanics, there have been several concerns about the methodology. These relate to the possibility that chloral hydrate may affect flow-volume measurements by altering upper airway caliber. There is also the possibility that physiological changes may be induced by inhalation of non-pharmacologic and pharmacologic nebulized solutions. The aim of this study was to investigate these phenomena in a group of normal infants. Thoracic gas volume was determined and respiratory mechanics measured using the passive and forced expiratory flow-volume techniques. Respiratory function was assessed in infants before and after 1) sleep was induced by administration of chloral hydrate (n = 10, mean age, 21 weeks); 2) inhalation of nebulized saline (n = 10, mean age, 19 weeks); 3) inhalation of nebulized salbutamol (n = 7, mean age, 22 weeks). A fall in tidal volume was found following administration of chloral hydrate but no significant change was seen in any other respiratory parameter. In addition, no change was seen in any parameter post-saline or salbutamol nebulization. This study provides data which support several basic assumptions made about the infant flow-volume techniques and should provide useful background information for future studies using these techniques.

Albuterol↗
PubMed1989

Response of normal infants to inhaled histamine.

The age at which nonspecific bronchial hyperresponsiveness (BHR) is first seen in humans is unknown, though both genetic and environmental factors have been implicated in its development. The current study aimed to establish whether BHR to histamine can be demonstrated in normal infants. Twelve infants, mean age of 7.8 months (range, 3 to 18 months), were studied. None had any history of a previous significant respiratory illness. Respiratory function was monitored using the maximal flow at function residual capacity (VmaxFRC) obtained with the forced expiratory flow-volume technique. Histamine was inhaled in doubling concentrations from 0.125 to 8 g.L-1. A greater than 30% fall in VmaxFRC was considered a response. All infants responded to histamine, the geometric mean concentration for their response being 1.4 g.L-1. Associated transient changes for the group were an increase in respiratory rate (p less than 0.02) and a fall in SaO2 (p less than 0.001). Forced expiratory flow-volume curves were concave in all infants after the last dose of histamine. We speculate that humans are born with "bronchial hyperresponsiveness" and that genetic or environmental factors determine which infants lose it thereafter.

Bronchi↗
PubMed1979

Behavioral treatment for depression: an evaluation of therapeutic components.

Designed study to determine the "active ingredients" in Lewinsohn's behavioral treatment for depression. Fifty-six men and women were screened for significant depression and were assigned to four experimental treatment groups: (1) an activities-increase group instructed to increment participation in reinforcing activities; (2) an expectancy-control group that participated in a fitness program; (3) a self-monitoring control that simply recorded activities and mood daily; and (4) an attention-control group. Consistent with an operant model of depression, the resulted indicated that increases in activities that Ss had rated as pleasureable alleviated depressed mood over a 30--day time period. While all Ss evidenced some improvement in mood, the activities-increase group showed significantly greater improvement than Ss in groups that did not increase their activity levels. Correlational analyses of daily activity and Depression Adjective Check List Scores proved additional support for the behavioral model of depression. The outcome for the four experimental groups was not different on a measure of belief in internal vs. external control of reinforcement.

Activities of Daily Living↗
PubMed1969

Awareness during caesarean section under general anaesthesia.

Investigation of a series of 150 obstetric patients, the majority undergoing caesarean section, showed the expected figure of 2% with factual recall. There was, however, a 17.3% occurrence of unpleasant recall-associated in 10 cases (6.6% of the total) with recall of pain. There was a negative correlation between the giving of a narcotic within six hours of the operation and the occurrence of unpleasant recall. Several other aetiological factors-age, parity, preoperative emotional tension, ventilation, nitrous oxide wash-out with oxygen, and nitrous oxide concentration-were investigated and no relation was found between them and unpleasant recall. It is suggested, therefore, that premedication still has an important function in light anaesthesia, using muscle relaxants, to prevent any form of unpleasant operative awareness.

Adult↗