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C Madden

Publications and source records attributed to C Madden.

30 records · Page 2Linked to original sources

Magnesium tocolysis: serum levels versus success.

The relationship between maternal serum magnesium levels and tocolytic success is poorly established. We performed a retrospective analysis of 101 episodes of preterm labor treated with magnesium sulfate and compared the initial, average, and maximum serum magnesium levels with tocolytic success at 48 hours and 7 days. There was no difference in the proportions of tocolytic success when serum levels were less than 6 mg/dl compared with levels of greater than or equal to 6 mg/dl. Similar analyses on either side of 5 mg/dl also revealed no significant relationship. Mean serum magnesium levels in patients with successful tocolysis were statistically similar to those of patients in whom tocolysis failed. Multiple logistic regression analysis also failed to establish a positive relationship between serum magnesium levels and tocolytic success. We conclude that serum magnesium levels alone should not serve as an end point of therapy.

Adult↗

Cross-modal, auditory-visual Stroop interference: a reply to Cowan and Barron (1987).

This series of experiments was performed to verify Cowan and Barron's (1987) reported effect of auditory color-word interference on a visual Stroop task. Extant theory predicts effects of irrelevant speech on visual memory tasks involving immediate, ordered recall of the items. Interference between the two sources of information (visual and auditory) is assumed to be located at the phonological store component of the articulatory loop. Perceptual tasks such as the Stroop task, which do not require use of the articulatory loop for rehearsal purposes, should not be similarly susceptible. The present data fail to replicate Cowan and Barron's findings, and are thus consistent with contemporary theory.

Adult↗

Mood state of heroin-dependent persons undergoing methadone detoxification.

A questionnaire (MSQ) was designed to evaluate subtle changes in subjective states accompanying methadone detoxification. A principal components analysis was applied to questionnaire data obtained from 29 male and female heroin-dependent persons at both moderate (42-22 mg) and low (21-1 mg) doses of methadone administration. Six factors were identified-a "schizophrenic" factor; general well-being; a mental outlook factor; a neurotic factor; a bipolar extroversion-introversion factor; a bipolar excitation versus euphoria-depression factor. A shift to a more negative mental attitude, and an increase in extroversion and excitability, was found with decrease in methadone dose.

Adult↗

Opiate-seeking behavior under conditions of methadone detoxification and removal.

This study was carried out to determine whether heroin-dependent persons, having completed methadone detoxification, can be maintained on an inert substance which has previously been associated with methadone. Forty heroin-dependent men and women were randomly allocated to either a "standard detoxification" group or a cordial substitution group. Results showed that subjects administered methadone-associated cordial after methadone detoxification could not be retained at the clinic for a time significantly beyond that of subjects in the standard detoxification group despite the inability of the subjects to accurately estimate methadone dosage. The role of cognitive factors is discussed.

Adult↗

The 'direct' pharmacological effects of heroin on operant responding and activity: the yoked-operant procedure.

The present study demonstrates a method which enables separation of the 'direct' pharmacological effects of heroin on activity and operant responding from the 'indirect' reinforcing effects of heroin. Experiment I was carried out at 0.1 mg/kg heroin with naive male albino Wistar rats (N = 21) from a La Trobe University (Bundoora, Australia) colony. Experiments II and III were carried out at 0.05 mg/kg (N = 21) and 0.2 mg/kg (N = 21) heroin doses with Wistar rats from a Monash University (Clayton, Australia) colony. Each experiment consisted of a 5-day pre-training period and a 10-day experimental period. Food-contingent operant behaviour was shaped in 14 animals during the first 4 days of the pre-training period. On day 5, baseline data was taken. Pairs of animals were then randomly yoked to one of seven naive 'executive' animals and the executive animals were allowed to self-inject heroin. Each self-injection of heroin by an executive animal led to a simultaneous injection of heroin to a yoked-heroin animal, and a simultaneous injection of saline to a yoked-saline animal. Results of 1-h data showed a significant decrement in food-contingent operant behaviour only for the yoked-heroin animals in the 0.2 mg/kg and 0.05 mg/kg groups. A significant decrement in both food-contingent operant behaviour and activity was found for the yoked-heroin animals at all three doses studied when data from the first half of 1-h sessions only was examined. It was concluded that the rate of self-injection demonstrated by executive animals was limited by the direct pharmacological effects of heroin on activity, and that the impairment of responding for food reflected this direct pharmacological effect of heroin. A theoretical model of reinforcement strength was subsequently proposed.

Animals↗

The effect of schedule removal on the maintenance of heroin self-injection.

The present study investigated the effect of schedule removal on the maintenance of heroin self-injection in 80% reduced body weight Wistar rats. During the acquisition phase, 42 animals were subjected to a fixed time 1 min food delivery schedule and were allowed to self-inject either heroin or saline for 10 days. During the maintenance phase (Days 11-15), animals in both the heroin and saline conditions were randomly allocated to schedule, no schedule, and no schedule plus food groups. Infusion rates, hot plate response latencies, and food intake were used as dependent measures to monitor differences between groups. The results revealed that schedule removal disrupted, but did not extinguish, heroin-seeking behaviour.

Animals↗

The involvement of interoceptive factors in the maintenance of heroin-seeking behavior.

The role of interoceptive stimuli in conditioned heroin-seeking behavior was investigated using forty-two naive male Wistar rats. A 21-day Phase I period in which 28 animals self-injected heroin in saline solution was followed by a 5-day Phase II period in which 7 animals were allowed access to the original solution; 7 animals were allowed access to saline only; 7 animals were allowed access to distilled water; and 7 animals were allowed no access to any solution. Results showed that only the heroin and (heroin-associated) saline groups shows a significant difference in operant rate compared to animals that had been continually exposed to saline only. It was concluded that heroin-seeking behavior was maintained in the (heroin-associated) saline group as a result of physiological conditioning following repeated association of saline with heroin.

Animals↗

The effect of EMG biofeedback on postoperative pain following abdominal surgery.

To investigate the effects of electromyography (EMG)-biofeedback on pain experienced during the immediate post-operative period following abdominal surgery, twelve patients were randomly assigned to either (1) EMG-biofeedback from abdominal muscles; (2) EMG-biofeedback from the frontalis muscles; or (3) were given no EMG treatment. EMG training consisted on one pre-operative 30 minute session, and three 30 minute postoperative sessions. All patients were able to reduce EMG activity. A within-sessions analysis of pain reports (on a 0-10 pain intensity scale) indicated that EMG biofeedback is an effective method of pain relief only when feedback is given to the muscle site involved in the operation.

Abdomen↗