Binding and hydrodynamic properties of muscarinic receptor subtypes solubilized in 3-(3-cholamidopropyl)dimethylammonio-2-hydroxy-1-propanesulfonate

The muscarinic receptor from the cerebral cortex, heart, and lacrimal gland can be solubilized in the zwitterionic detergent 3-(3-cholamidopropyl)dimethylammonio-2-hydroxy-1-propane sulfonate (CHAPSO) with retention of high affinity [3H]N-methyls-copolamine binding. However, in this detergent there are significant differences in the binding properties of the receptors, compared with those observed in membranes and digitonin solution. Some agents retain a degree of selectivity. In the heart and cortex, agonists can bind with high affinity to a receptor-GTP-binding protein complex. A second, lower affinity, agonist binding state is also present, which resembles a class of sites seen in membranes but not in digitonin solution. The high affinity agonist binding state has been resolved from the lower affinity state on sucrose density gradient centrifugation. Hydrodynamic analysis suggests that the high affinity state is approximately 110,000 Da larger than the lower affinity state. The binding properties of the receptor in CHAPSO can be altered to those seen in digitonin by exchanging detergents after CHAPSO solubilization.     

One-Year Follow-up of Duodenal Ulcers after 1-Wk Triple Therapy for Helicobacter pylori

Objective : to study the ulcer recurrence rate of Helicobacter pylori-positive duodenal ulcers at 1 yr after eradication of the bacteria by triple therapy. Method : Patients with H. pylori-positive duodenal ulcers were randomized to receive either triple therapy for 1 wk plus omeprazole for 4 wk (THple+OMP) (n = 78), or omeprazole alone (OMP) for 4 wk (N = 77). Patients were followed up every 3 months for symptom enquiry. At 1 yr, all asymptomatic patients were invited to attend for gastroscopy. Results : At 8 wk, 16 patients in the OMP group and four in the Triple+OMP group had an ulcer. During the 1-yr period, 12 patients in the OMP group and no patient in the Triple+OMP group developed symptomatic ulcers. At follow-up endoscopy at 1 yr, another 10 ulcers were detected in the OMP group and two in the Triple+OMP group. Fifteen patients in the OMP group and 13 in the Triple+OMP group were lost to follow-up. In total, ulcers were de-tected in 39 of 61 (64%) assessahle patients in the OMP group, and in six of 65 (97o) assessahle patients in the Triple+OMP group after I yr (χ² test: p < 0.001). Of the patients whose H, pytori were successfully eradicated hy Triple+OMP at 8 wk, 90% remained H. pylori negative at 1 yr. Conclusion : Triple therapy for 1 wk eradicates H, pylori infection and significantly reduces duodenal ulcer relapses.     

Controlled trial of nebulized albuterol in children younger than 2 years of age with acute asthma.

To determine the response to nebulized beta 2 agonist, 28 children younger than 2 years of age who visited the emergency department during an episode of acute asthma were studied. Each subject had a previous history of recurrent wheezing episodes. They were randomly assigned to receive two administrations of either nebulized albuterol (0.15 mg/kg per dose) or placebo (normal saline) with oxygen, 1 hour apart. After two nebulizations, the albuterol-treated patients had a greater improvement in clinical status (respiratory rate, degree of wheezing and accessory muscle use, total clinical score, and arterial oxygen saturation) than the placebo group. None of the patients in the albuterol group experienced a decrease of arterial oxygen saturation of greater than or equal to 2%. It is concluded that a trial of nebulized beta 2 agonists is warranted in the treatment of acute asthma in infants and young children.     

Efficacy of nimodipine in the prophylaxis of migraine

The efficacy of nimodipine in the prophylaxis of migraine was assessed in a double-blind, placebo-controlled, cross-over study carried out on 33 patients, 20 of whom suffered from classic and 13 from common migraine. Four patients dropped out, but not as a result of the side effects of the drug. The duration of drug treatment was 8 weeks. The dosage used was 30 mg four times daily. Nimodipine proved to be better than placebo, the number of migraine attacks and severity of headache showing a significant reduction. The drug was well tolerated and no marked side effects were noted. The results suggest that nimodipine is a useful new prophylactic drug for migraine, but further studies are needed before its final value can be evaluated.