Effects of infused histamine on asthmatic and normal subjects: comparison of skin test responses

The effect of histamine infused intravenously at sequentially increasing concentrations (0.05, 0.1, 0.25, 0.5, and 1 microgram/kg/min) on the wheal responses to intradermal histamine and compound 48/80 in eight normal and five asthmatic subjects and to allergen skin tests in five asthmatic subjects was measured. These measurements were repeated following pretreatment with the H-1 antagonist hydroxyzine or the H-2 antagonist cimetidine, either alone or in combination. Histamine infused in progressively increasing concentrations had no effect on histamine, compound 48/80, or allergen skin tests either before or after H-1 or H-2 antihistamine treatment. No significant difference was found in the concentration of histamine or compound 48/80 required to elicit a 10-mm wheal in normal or asthmatic patients. Pretreatment with the H-2 antagonist alone had no effect on histamine or compound 48/80 skin tests in either group. However, the H-1 antagonist significantly reduced the wheal response to histamine (p less than 0.05 normal; p less than 0.025 asthmatics) and compound 48/80 (p less than 0.05 normal; p less than 0.025 asthmatics) in both groups. The combination of H-1 and H-2 histamine antagonists was not significantly different from the H-1 antagonist alone. Antigen skin testing was suppressed 82% by the hydroxyzine alone; no significant suppression was induced by cimetidine alone, and the combination of hydroxyzine plus cimetidine was only slightly more effective than hydroxyzine alone. The results indicate that blockade of histamine H-2 receptors with cimetidine has little or no additive effect on H-1 antagonist-suppressed skin test responses to histamine, compound 48/80, or antigen. Furthermore, the capacity of histamine to suppress histamine release in vitro from basophils was not demonstrated in vivo assessing skin mast cell responses. This observation combined with earlier studies on the human lung mast cell, which also failed to demonstrate that histamine had an inhibitory action, suggests that the human mast cell may not respond to histamine like the basophil and that this discrepancy may represent a fundamental difference in the cell types.

Effects of vasopressin on human memory functions

Arginine vasopressin and a number of its synthetic analogs augment memory functions in experimental animals. One of these analogs, 1-desamino-8-D-arginine vasopressin (DDAVP), influences human learning and memory. Cognitively unimpaired, as well as cognitively impaired adults, treated with DDAVP for a period of several days, learn information more effectively, as measured by the completeness, organization, and consistency (reliability) of recall. DDAVP also appears to reverse partially the retrograde amnesia that follows electroconvulsive treatment.

Barium impaction as a complication of gastrointestinal scleroderma

Two patients with scleroderma of the bowel experienced life-threatening barium impaction after upper intestinal x-ray studies. Although the frequency of this complication is unknown, the difficulty of managing it when it occurs makes prevention imperative. X-ray studies should be performed only after careful consideration of the risks and benefits. When x-ray studies are performed, the patient should be vigorously purged soon thereafter, and a follow-up roentgenogram should be obtained to confirm adequate removal of barium.

Fulminant herpes simplex hepatitis in an adult: report of a case in renal transplant recipient

A case of disseminated herpes simplex infection is reported in a 31-year-old renal transplant recipient. The patient presented with a unique clinical syndrome: high fever, severe sore throat with buccal and pharyngeal ulcerations, fulminant hepatitis, thrombocytopenia, and leukopenia. The patient died from hepatic failure, disseminated intravascular coagulopathy, and upper gastrointestinal bleeding. The diagnosis was made by positive herpes simplex virus culture from the throat, and was confirmed at autopsy by typical Cowdry's type A intranuclear inclusions in hepatocytes with positive herpes simplex virus culture from the liver. Review of the literature reveals that other reported cases have had very similar clinical findings, making disseminated herpes simplex infection with fulminant hepatitis a recognizable syndrome.

Rumen micro-organisms in red deer, hill sheep and reindeer in the scottish highlands

The micro-organisms in rumen samples from Red deer, hill sheep and reindeer grazing their natural pastures in the Scottish Highlands were examined at different seasons over a number of years. The total counts of bacteria and protozoa varied with the seasons, and were lowest in winter when fermentative activity was also at its lowest. As is usual in roughage-fed ruminants, viable counts were only a very small proportion of the total counts. The reindeer rumens had the highest concentrations of bacteria. There were no consistent differences in the types of bacteria between seasons, but although there were no bacteria peculiar to any animal species the balance of predominant types varied between the species. The principal types of bacteria were similar to those found in domesticated ruminants. The numbers of protozoa in the Red deer were higher than those in the sheep, and the concentrations in reindeer were higher than those generally reported for domesticated cattle or sheep. A number of species of protozoa were found in each animal and the predominant species differed in the different animals.

Rumen function in red deer, hill sheep and reindeer in the scottish highlands

Red deer, sheep and reindeer grazing on their normal hill ranges were examined at intervals over a period of four years. Samples from the digestive tract were taken at different seasons and processed in the field. The Red deer and reindeer were killed before samples were taken; rumen samples from the sheep were taken by stomach tube, but a number of animals were also killed at different seasons to correlate stomach tube and whole rumen samples. The animals sampled were representative of the general condition of the herds. Examinations were made for parasites and any pathological conditions. In most instances parasitic infections were slight. Apparent seasonal changes were found in the compositions of the diets. The Red deer and sheep ate principally heather and grass, the proportion of heather increasing in the winter. The reindeer ate mainly grass in the summer, with lichens and grass forming the winter diet, and these animals seemed to have a higher nutritional status in the winter than did the other two species. The weights of the animals and of their rumen contents, the concentrations of rumen ammonia and volatile fatty acid, and the rates at which different dietary components were fermented are recorded. Rumen fermentation was low in winter and the diets were generally inadequate for the animals. A lack of nitrogen seemed to be a major factor. Some data on caecal contents are also given.

Subsensitivity to epinephrine following the administration of epinephrine and ephedrine to normal individuals

Cardiovascular and metabolic responses to exercise and consecutive epinephrine infusions 24 hours apart were measured in 7 normal individuals before and following a week's administration of ephedrine sulfate. There was evidence of less beta adrenergic response to the second control epinephrine infusion compared to the first control infusion, and the depression of the rise in blood lactate was significantly different. A week of ephedrine produced more profound depression of the beta adrenergic responses to epinephrine with significant differences in the rise in blood glucose and lactate, and the pulse and blood pressure responses. Furthermore, these same responses remained significantly altered when a second epinephrine infusion was performed 36 hours following the last dose of ephedrine. The alterations in the response to epinephrine induced by ephedrine are consistent with the concept of effector cell "subsensitivity," an adaptive response to prolonged excessive stimulation.