Medical treatment of esophageal achalasia. Double-blind crossover study with oral nifedipine, verapamil, and placebo.

Calcium channel blockers have been previously shown to decrease lower esophageal sphincter (LES) pressure and improve symptoms in achalasia. We performed a placebo-controlled, double-blind, crossover study to assess the effects of oral nifedipine and verapamil on LES pressure, amplitude of esophageal body contraction, and clinical symptomatology in eight patients with symptomatic achalasia diagnosed by endoscopy, barium swallow, and manometry. Patients were randomized to receive up to 20 mg nifedipine, 160 mg verapamil, or placebo and underwent esophageal manometry before (baseline) and after four weeks on each drug. Diary cards were kept to record and grade symptoms and drug plasma level determinations were correlated with manometric and clinical findings. Both nifedipine and verapamil caused a statistically significant decrease in mean LES pressure, but only nifedipine caused a significant decrease in the amplitude of contractions of the smooth muscle portion of the esophagus. No statistically significant differences in the overall clinical symptomatology were noted with any of the drugs, although some individual improvements in dysphagia and chest pain were noted. We conclude that, despite the reduction in LES pressure and contraction amplitude of the distal esophageal body, oral nifedipine and verapamil do not significantly alter the clinical symptomatology of patients with achalasia.

Chlorinated hydrocarbon insecticides in Colorado beef cattle serum--a pilot environmental monitoring system.

A pilot project was initiated to test an existing animal disease surveillance system for use in monitoring environmental pollutants. Eleven chlorinated hydrocarbon insecticides were assayed to provide an indication of environmental contamination. A total of 241 bovine serum samples from 53 Colorado beef ranches was tested; 123 samples (51%) were found to contain detectable concentrations of 1 or more of 11 chlorinated hydrocarbons. There were a total of 203 occurrences of a compound being found at a level exceeding the detection limit. Heptachlor, heptachlor epoxide, lindane, and oxychlordane were the insecticides detected most frequently in bovine sera. This pilot study supports the use of domestic food-producing animals as sentinels of environmental contamination with insecticides.

Chronic exposure of sheep to a zinc smelter in Peru.

Liver levels of arsenic, cadmium, copper, lead, manganese, and zinc were assessed in adult female sheep living in the vicinity of a zinc smelter in Peru. The study was conducted on a large sheep-raising cooperative divided into seven management units, operated under a standardized husbandry system. Soil samples were analyzed for the same metals at varying distances from the smelter. A gradient of concentration of heavy metals in soil was found between 1 and 56 km from the smelter. Soil concentrations for all metals except manganese decreased significantly with increasing distance from the smelter. The strongest correlations were found for copper, lead, and zinc (P less than 0.001). Topographic features and prevailing wind direction appeared to play a role in the dispersion of pollutants. Liver samples were obtained from 153 sheep on five units of the cooperative. The centers of the units sampled were between 13 and 56 km from the smelter. Hepatic concentrations of arsenic, lead, manganese, and zinc decreased significantly with increasing distance from the smelter. Liver arsenic and liver zinc were significantly related to soil concentrations. Liver levels of arsenic, cadmium, lead, and manganese in sheep from the cooperative were significantly higher than those detected in control sheep from southern Peru. Sheep populations may serve as biological monitors for heavy metal accumulation and environmental carcinogenesis.

The case manager-home visitor.

The roles of case managers and home visitors take various forms in practice in different services. This article describes usages in relation to handicapped infants, toddlers, and their families, and makes a strong point for combining the roles in this service.

Investigation of solid-phase ozonolysis reactions for use in a personal sampling method for ozone.

Three ozonolysis reactions were tested in the solid phase for reproducibility and quantitative yield of an aldehyde reaction product. The three starting olefins were t-stilbene, 4,4'-dimethoxystilbene and 1,2-di-(4-pyridyl) ethylene which, when reacted with ozone, gave benzaldehyde, p-anisaldehyde and pyridine-4-aldehyde, respectively. The starting olefins were coated on a variety of solid substrates, exposed to known ozone concentrations and then analyzed for the corresponding aldehyde with a gas chromatograph equipped with a flame-ionization detector. The best combination found for all three reactions was with the starting olefin coated on 30/60 mesh Florisil. Consistent yield was obtained for the methoxystilbene reaction within one batch of sorbent; very reproducible results were obtained within four replicate samples for the pyridyl ethylene reaction. No consistency was obtained, however, with any of the reactions between batches of sorbents and between different sets of samples. Several problems were identified which led to the inconsistent results. The t-stilbene and pyridyl ethylene sorbents oxidized over time while stored to form high aldehyde blanks. All three aldehydes, once formed on the sorbent, were volatilized off the sorbent bed as a result of airflow through the bed. Several different solid sorbents were tried unsuccessfully as traps for the purged aldehydes. Finally, lower flow rates resulted in the finding that significant amounts of the aldehydes also were being formed by oxygen in the air sample. Since oxygen was a strong positive interferent, these reactions were considered unacceptable as indicators of ozone.

Colonic myoelectric activity in persons with spinal cord injury.

Colonic myoelectric activity was recorded from six para- or quadriplegic subjects with spinal cord injury and seven normal controls via bipolar electrodes in contact with the rectal mucosa. Recordings were carried out in the fasting (basal) state and after stimulation by a standard meal and by 1.0 mg neostigmine intramuscularly. The recordings were visually analyzed for spike activity, average slow wave frequency, and percentage occurrence of subsets of slow wave frequency (2-4 and 5-12 cycles/min). The spinal-cord-injured subjects had significantly more spike wave activity in the basal state than did the controls (12.6 spikes per 10 min vs 3.3). However, meal stimulation did not lead to an increase in spike activity in the spinal-cord-injured subjects (13.7 spikes per 10 min vs 12.6) while it did in the controls (6.4 vs 3.3 spikes per 10 min). Neostigmine significantly increased spike activity in both groups. There was no difference in average slow wave frequency nor any slow wave subsets between the two groups studied. Thus persons with spinal cord injuries have higher basal colonic myoelectric activity than normals but lack a demonstrable gastrocolic reflex. We conclude that the central nervous system exerts a tonic inhibitory influence on basal colonic motility and appears to participate in the gastrocolic reflex.

Suspected foodborne carbamate pesticide intoxications associated with ingestion of hydroponic cucumbers.

In the period April 1--15, 1977, nine residents of one Nebraska town experienced violent illnesses with short duration following ingestion of locally grown hydroponic cucumbers. Despite a thorough investigation, the etiologic agent of illness was not determined. From July 16--25, 1978, a second similar outbreak occurred in an adjacent city. Five individuals experienced illness similar to that which occurred in 1977, also following ingestion of hydroponic cucumbers grown at the same greenhouse involved in the 1977 outbreak. The carbamate insecticide, aldicarb, was detected in some cucumbers grown at the hydroponic greenhouse. The source of this chemical in the greenhouse could not be determined.