Prostaglandin D2 is released during acute allergic bronchospasm in man.
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Biomedical subjects
R Workman
Publications and source records attributed to R Workman.
Caffeine and hypertension.
The effect of prolonged caffeine administration on blood pressure in hypertensive subjects was assessed in a double-blind placebo-controlled study. Eighteen hypertensive subjects participated, nine of whom received placebo throughout the study and nine of whom received placebo during the first three days, caffeine during the subsequent seven days, and placebo during the final four days of the two-week study. Those who received caffeine were given 250 mg with meals three times daily. There were no untoward reactions in the course of the study, but one subject with unacceptably high blood pressures while receiving placebo had to be discharged from the study to resume antihypertensive therapy. Systolic blood pressure was immediately increased (9.2 +/- 3.4 mm Hg) within 15 minutes after the first dose of 250 mg of caffeine. On the first day of caffeine, systolic pressure was increased a mean of 7.3 +/- 4.0 mm Hg, but this was no longer significant after the initial day of caffeine administration. Diastolic pressure showed a trend toward increasing, but this never reached significance. The minor increases in plasma catecholamine levels and plasma renin activity were not significant on either a short- or long-term basis. After discontinuation of caffeine, no overshoot phenomena were observed. It is concluded that prolonged administration of caffeine is not associated with significant elevation in blood pressure, plasma catecholamine levels, or plasma renin activity in patients with borderline hypertension.
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Management of the syndrome of inappropriate antidiuretic hormone secretion in small cell lung cancer.
From 1976 to 1980, 18 of the 250 patients (7%) seen with small cell carcinoma of the lung had clinically evident inappropriate secretion of antidiuretic hormone (ADH). Hyponatremia was usually severe (116 +/- 7 meq/l), and eight patients showed symptoms of water intoxication at the time of diagnosis. Of the eight patients who had plasma ADH measured at diagnosis, seven had elevated values (mean 52.0, range 16.1 - greater than 250 pg/ml). Intensive combination chemotherapy produced objective tumor responses in all patients, and syndrome of inappropriate ADH secretion (SIADH) resolved in 16 of 17 evaluable patients within three weeks of initiation of treatment. ADH values after therapy were normal, and all patients maintained a normal serum sodium during the period of tumor remission in spite of unrestricted fluid intake. All 17 evaluable patients have developed progressive cancer, but only 10 have manifested recurrent SIADH. Patient survival was similar to the overall population of small cell carcinoma patients without SIADH. The indirect methods of treatment for SIADH (fluid restriction, demeclocycline, lithium, urea) are frequently of transient value while awaiting a response to chemotherapy or in patients with resistant tumors. However, the initial treatment of choice for SIADH associated with small cell carcinoma of the lung is combination chemotherapy.
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Tolerance to the humoral and hemodynamic effects of caffeine in man.
Acute caffeine in subjects who do not normally ingest methylxanthines leads to increases in blood pressure, heart rate, plasma epinephrine, plasma norepinephrine, plasma renin activity, and urinary catecholamines. Using a double-blind design, the effects of chronic caffeine administration on these same variables were assessed. Near complete tolerance, in terms of both humoral and hemodynamic variables, developed over the first 1-4 d of caffeine. No long-term effects of caffeine on blood pressure, heart rate, plasma renin activity, plasma catecholamines, or urinary catecholamines could be demonstrated. Discontinuation of caffeine ingestion after 7 d of administration did not result in a detectable withdrawal phenomenon relating to any of the variables assessed.
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Moisture analysis of lyophilized allergenic extracts.
A simple, relatively fast, coulometric method to determine both the surface-moisture and bound-moisture content of a wide variety of lyophilized, allergenic extracts has been developed. The method has been found suitable for the detection of residual-moisture levels in both lyophilized protein and carbohydrate samples. Isothermal rate-changes in moisture desorption, normalized with respect to sample size and plotted versus time, yield desorption curves which are characteristic of several individual classes of lyophilized materials. The method, when compared to the Official Loss on Drying Procedure for Lyophilized Biologicals, has proven to be faster (1.5 hr.) and more sensitive, with increased specificity and accuracy.
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The significance of enthesopathy as a skeletal phenomenon.
Enthesophytes and enthesopathy, while easy to define, represent a phenomenon of unclear clinical significance. As the high frequency in skeletal populations suggests that enthesopathy may not be disease-specific, the nature of the reaction was assessed in 872 individuals from a representative skeletal population, subdivided into groups characterized by the presence or absence of rheumatoid arthritis, spondyloarthropathy, calcium pyrophosphate deposition disease and diffuse idiopathic skeletal hyperostosis (DISH). Achilles, plantar fascia, patellar and iliac crest entheses were examined for evidence of calcific overgrowth or "erosions." Enthesophytes were found to be a phenomenon of aging in individuals, and unrelated to the presence of inflammatory arthritis or DISH. The frequency increased with age, independent of sex or the site examined, plateauing in frequency after age 60. Enthesophytes in individuals under age 60 were usually unrelated to any underlying disorder. The absence of effect of underlying forms of arthritis on the frequency of enthesophytes at the patellar, Achilles and plantar sites suggests that mechanical factors outweigh the "enthesis calcifying" impact of such disorders as spondyloarthropathy, calcium pyrophosphate deposition disease and DISH. Individuals with rheumatoid arthritis, however, manifested a less severe iliac crest enthesial reaction, in keeping with the minimal reactive new bone formation characteristic of its erosions. Analysis of Achilles, plantar, and patellar enthesial reactions as a function of underlying inflammatory arthritis or DISH also revealed no significant variation with the underlying process. Cortical discontinuity at enthesial sites was a relatively infrequent phenomenon. While calcaneal discontinuities were originally thought to be erosive in nature, these observations suggest the possibility of tendon avulsion injuries.
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