The discriminative stimulus and subjective effects of d-amphetamine,phenmetrazine and fenfluramine in humans

The discriminative stimulus (DS) and subjective effects of d-amphetamine (AMP), phenmetrazine (PMT) and fenfluramine (FFL) were studied in a group of normal healthy adults. Subjects (N=27) were trained to discriminate between placebo and 10 mg AMP (PO). Fourteen of the subjects (discriminators) reliably learned the discrimination, whereas the other 13 did not. Nearly all discriminators labelled AMP as a stimulant, and AMP, relative to placebo, increased ratings of drug liking and general activity level, and produced typical stimulant-like subjective effects, as measured by the Profile of Mood States, the Addiction Research Center Inventory, and a series of visual analog scales. The discrimination accuracy of discriminators increased as a function of hour after drug ingestion, as did analog ratings of how certain subjects were that their discrimination responses were correct. Discriminators were tested with doses of PMT (25 and 50 mg) and FFL (20 and 40 mg) to determine whether the DS properties of these drugs would substitute for those of AMP. Both doses of PMT consistently substituted for AMP, and PMT produced subjective effects very similar to those of AMP. Conversely, neither dose of FFL consistently substituted for AMP, and FFL produced essentially no subjective effects. These findings are consistent with results from discrimination studies with other species, and provide further evidence of the validity of this procedure for studying the DS properties of drugs in humans. Offprint requests to: L.D. Chait     

Temperature changes during the first day of life in the North Staffordshire Maternity Hospital.

A prospective study of post-delivery temperature changes from birth to 24 h, carried out in a busy District General Hospital is reported. The temperature fall after delivery was less than expected and reflected a high level of awareness of the dangers of hypothermia. On the basis of the findings of the survey, hypothermia in the first 24 h can be defined as a rectal temperature of less than 36.4 degrees C. Those babies who did become hypothermic were significantly more likely to be of low birth weight or preterm gestation.     

A randomized prospective study comparing delivery with metal and silicone rubber vacuum extractor cups.

OBJECTIVE: To determine the relative benefits and complications of assisted vaginal delivery with metal and silicone rubber vacuum extractor cups. DESIGN: Prospective randomized controlled study. SETTING: A busy referral maternity hospital in Kathmandu, Nepal. SUBJECTS: 101 women were assigned to delivery with the Silc-cup and 98 to delivery with the metal cup. MAIN OUTCOME MEASURES: Success rate at achieving delivery with the assigned instrument and incidence of neonatal trauma. Analysis was by 'intention to deliver' with women remaining in their original group regardless of the eventual mode of delivery. RESULTS: Randomization resulted in two groups of women similar in respect of age, parity, gestation and indication for delivery. The overall success rate was similar for the two instruments (Silc-cup 85% and metal cup 87%). The Silc-cup was more likely to fail if there was excessive caput (seven failures compared with one in the metal cup group). The frequency of clinically significant maternal trauma was low in both groups. There were fewer babies with clinically significant scalp trauma in the Silc-cup group (22%), compared with the metal cup group (37%). CONCLUSIONS: The data indicate a greater tendency for the Silc-cup to fail when excessive caput is present but that metal cups are associated with increased scalp injuries.     

Segmental intestinal muscular thinning: a possible cause of intestinal obstruction in the newborn

Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant.