Comparison of two antimuscarinic drugs, pirenzepine and propantheline, on gastric acid secretion, serum gastrin concentration, salivary flow and heart rate in patients with duodenal ulcer disease

Effects of orally-administered pirenzepine and propantheline bromide on food-stimulated gastric acid secretion, serum gastrin concentration, salivary flow and heart rate were compared in 10 duodenal ulcer patients in a placebo-controlled, double-blind study. Pirenzepine inhibited acid secretion by 25, 36 and 44% at doses of 50, 100, and 150 mg, respectively, while propantheline inhibited acid secretion by 32 and 41% at doses of 15 and 45 mg, respectively. None of the doses of pirenzepine affected food-stimulated serum gastrin concentrations, whereas 45 mg propantheline increased serum gastrin concentration significantly above placebo control. Enhancement of gastrin release by propantheline was not due to its antisecretory effect since intragastric pH after the meal was held constant at 5.0 by intragastric titration in vivo. Pirenzepine had no significant effect on heart rate and little or no inhibitory effect on salivary volume, depending on the dose administered. By contrast, both doses of propantheline increased heart rate and reduced salivary volume significantly (P less than 0.05). Thus, pirenzepine and propantheline in the doses administered inhibited acid secretion to approximately the same extent but pirenzepine had fewer effects on other organs.     

Exposure to Inhaled Isobutyl Nitrite Reduces T Cell Blastogenesis and Antibody Responsiveness

Exposure to Inhaled Isobutyl Nitrite Reduces T Cell Blastogenesisand Antibody Responsiveness. SODERBERG, L. S. F., AND BARNETT,J. B. (1991). Fundam. Appl Toxicol. 17, 821–824. Isobutylnitrite is a drug of abuse popular among male homosexuals andamong adolescents. In order to approximate the nitrite exposuresof inhalant abusers, mice were treated with 900 ppm isobutylnitrite in an inhalation chamber for 45 min per day for 14 days.After 14 consecutive days of exposure to isobutyl nitrite, miceweighed an average of 4% less than mice exposed to air. Thespleens of nitrite-exposed mice weighed 15% less and had 24%fewer cells per spleen than those of controls. Adjusted forequal cell numbers, T cell mhogenic and allogeneic proliferativeresponses were significantly reduced by 33 and 47%, respectively.The frequency of T-dependent plaque-forming cells (PFC) wasinhibited by 63% and the total number of PFC per spleen wasreduced by 72% in nitrite-exposed mice. In contrast, B cellproliferative responses to LPS were unaltered, suggesting thatthe toxicity of isobutyl nitrite did not affect all lymphoidcells equally. The data suggest that habitual inhalation ofisobutyl nitrite could impair immune competence and that toxicityappeared to be directed toward T cell functions.     

A graft-versus-host disease-like syndrome with carcinomatosis

A patient who developed a syndrome resembling chronic graft-versus-host disease in association with disseminated carcinoma is described. There has only been one previous report of this association.     

Radio-Frequency Radiation and Birth Defects: Is There a Risk to Human Health?

This paper reviews studies in the radiofrequency spectrum which includes radiation from cellular telephones and other wireless networks. Modern mobile communications technology uses pulsed digital systems operating at frequencies of 900–1, 800 MHz. Although there are some reports that pulsed exposures may be more likely to produce biological effects than an equivalent energy deposition from continuous wave, there are relatively few data relevant to the frequency or the pulsing conditions used in telecommunications. Most of the literature on teratological studies on animals reports results of continuous wave transmission, 2,450 MHz (microwave oven frequency), at substantial levels of exposure; exceeding internationally prescribed safety levels for radio-frequency radiation (RFR). Gross developmental anomalies were associated with significant increases above normal in embryonic or fetal temperature. The issue of possible athermal effects has not been properly resolved. Although it is now largely accepted that some biological responses to RFR occur at levels below which thermal mechanisms may be implicated, the absence of relevant directed research programs prevents sensible scientific conclusions on the consistency of data and their relevance to human health. Considering these limitations, there is no convincing independently verified evidence that exposures to RFR from current mobile telecommunications technology presents a serious health risk to human prenatal development.     

Variations in the Relationships Between Total 59Fe Uptake and the Uptakes Into Heme and Nonheme Fractions of Spleen and Bone Marrow in Irradiated Mice and Mouse Radiation Chimeras

A chemical method for the separation ofheme and nonheme iron-containing fractions in mouse tissues has been used tostudy the uptake of ⁵⁹Fe into both theheme and nonheme iron fractions inspleen and femoral bone marrow, in orderto investigate the possible relationshipsbetween the total uptake into spleen tissue and the rate of uptake into the hemefractions. In control mice, only aboutone third of the ⁵⁹Fe is directly associated with heme during the first dayafter administration, and this fraction decreases as radioactive red cells are released from the spleen into blood. Tendays after X-irradiation of mice, the proportion of ⁵⁹Fe in the spleen heme fraction 6 hr after intraperitoneal administration decreased from about 30 to 10%of the total splenic activity as the radiation dose was increased from 500 to 750rads. A similar alteration in the proportion of ⁵⁹ Fe in the spleen haem fractionoccurred in mouse radiation chimeras asthe dose of injected syngeneic bonemarrow cells was reduced from 5 x 10⁵to zero. Similar results were found infemoral bone marrow. These results indicate that in this system the rate of uptake into whole tissue is not a measureof the uptake into heme; it is necessary,therefore, to use the method involvingthe measurement of iron uptake intoheme, rather than the total tissue uptake,when estimating hemoglobin synthesisor erythropoiesis.

Submitted on February 15, 1971 Revised on April 5, 1971 Accepted on April 8, 1971