Lack of endogenous crossreactivity with three digitoxin radioimmunoassays in adults with renal insufficiency

The possibility of interference by apparent digitoxin-like immunoreactive substance (DTLIS) with three radioimmunoassays was studied in patients with renal insufficiency. From each of 25 adult patients with renal insufficiency and 25 age-matched and sex-matched control subjects with normal renal function, a single serum sample was obtained and assayed for digitoxin content by three commercially available radioimmunoassays (GammaCoat, Coat-A-Count, and the Wien assay). Although two of the three assays found measurable concentrations, the difference in apparent digitoxin concentrations between the control subjects and those with renal insufficiency was not significant. Assay interference could not be explained on the basis of differences in age, serum creatinine concentration, or weight. The magnitude of DTLIS interference in relation to the digitoxin therapeutic range appears to be small with the radioimmunoassays used in this study.     

Practical and technical considerations in establishing an intraoperative radiation therapy program in the community practice

The Radiation Oncology Center in Sacramento, California, has developed a procedure for establishing an intraoperative radiation therapy facility in a community practice. The logistics pertaining to personnel, equipment, physical measurements, and quality assurance are presented. Particular emphasis is given to the most effective means of acquiring the large quantity of data needed to ensure a program of acceptable quality.     

Uveitis in the internist's office: are a patient's eye symptoms serious?

Uveitis is an inflammatory process that may affect one or several specific areas of the eye. But when a patient presents to an internist with eye symptoms, be it photophobia, "floaters," or red eye, the diagnosis is not always clear. If the diagnosis of uveitis is made, internists must search for an underlying cause, such as infection or an autoimmune disease.     

Medications for migraine prophylaxis

Sufficient evidence and consensus exist to recommend propranolol, timolol, amitriptyline, divalproex, sodium valproate, and topiramate as first-line agents for migraine prevention. There is fair evidence of effectiveness with gabapentin and naproxen sodium. Botulinum toxin also has demonstrated fair effectiveness, but further studies are needed to define its role in migraine prevention. Limited evidence is available to support the use of candesartan, lisinopril, atenolol, metoprolol, nadolol, fluoxetine, magnesium, vitamin B2 (riboflavin), coenzyme Q10, and hormone therapy in migraine prevention. Data and expert opinion are mixed regarding some agents, such as verapamil and feverfew; these can be considered in migraine prevention when other medications cannot be used. Evidence supports the use of timed-release dihydroergotamine mesylate, but patients should be monitored closely for adverse effects.