Diagnostic dilemma of an unsuspected hyperfunctioning accessory parathyroid gland after total parathyroidectomy with autotransplantation in a peritoneal dialysis patient.

Persistent or recurrent hyperparathyroidism in patients with chronic renal failure may be a frustrating problem. We report a case history of a peritoneal dialysis patient who underwent total parathyroidectomy with autotransplantation for secondary hyperparathyroidism, developed tertiary hyperparathyroidism, and in an attempt to control hypercalcemia underwent seven partial resections of the autotransplant. Subsequently, a total excision of the parathyroid autograft was performed, but the patient continued to have hyperparathyroidism and unexpectedly was found to have a hyperplastic fifth parathyroid gland identified by thallium-technetium subtraction scan. The fifth gland was removed, and a part was implanted in the right forearm; however, the autoimplant had to be completely removed because of rapidly developing hypercalcemia. Hypercalcemia was controlled, but elevated levels of parathormone persisted. Remaining parathyroid tissue could not be found.

Comparative antitussive effects of dextrorphan, dextromethorphan and phencyclidine.

The possible antitussive effects of dextrorphan (the (+) isomer of levorphanol) and phencyclidine (PCP) were compared to well known antitussive properties of dextromethorphan in the post-halothane anesthetized decerebrate cat in which cough was elicited by direct electrical stimulation of the cough center. Dextrorphan, when injected i.a. (0.05-0.32 mg kg-1) or i.v. (1 to 3 mg kg-1), PCP i.a. (0.1-0.32 mg kg-1) or i.v. (1.0 mg kg-1) had no effect on electrically elicited cough. After i.v. administration, dextrorphan caused a variable effect on respiration but did not have any respiratory effect with i.a. administration of the drug. PCP injection i.a. at 0.32 mg kg-1 severely inhibited respiration though coughing could still be elicited. But i.v. administration of 1.0 mg/kg-1 suppressed both cough and respiration for several hours. Dextromethorphan inhibited cough upon both i.a. and i.v. injection. The mean effective i.a. dose was 0.063 mg kg-1. A ten times higher dose was necessary (0.65 mg kg-1) for cough suppression by the i.v. route. It is concluded from the i.a./i.v. ratio that dextromethorphan has specific central antitussive activity not possessed by dextrorphan and PCP.

Comparative effects of diazepam and midazolam on paraoxon toxicity in rats.

The present study was undertaken to compare the effectiveness of a new water-soluble benzodiazepine, midazolam, to diazepam, both administered im for protection against diethyl-p-nitrophenyl phosphate (paraoxon) toxicity. Adult male Sprague-Dawley rats were pretreated with midazolam or diazepam (0.32-32.0 mg/kg) alone or in combination with atropine (10.0 mg/kg). Twenty minutes later 2 X LD50 of paraoxon was injected sc and the incidence of seizures and death were recorded for 24 hr. In another series of experiments, the LD50 of paraoxon was evaluated in the rats pretreated im with atropine (10.0 mg/kg) and midazolam or diazepam (10.0 mg/kg). Pretreatment with atropine alone did not prevent paraoxon-induced seizures but did reduce mortality. Both benzodiazepines were very effective alone or when combined with atropine in reducing the incidence of paraoxon-induced seizures. When given alone, neither benzodiazepine protected against paraoxon-induced mortality. However, when combined with atropine both benzodiazepines dramatically decreased the lethality of 2 X LD50 of paraoxon. In equal doses given im, midazolam proved to be more potent than diazepam.

Evidence for a central site of action for the antitussive effects of caramiphen.

The antitussive properties of caramiphen edisylate were studied in the decerebrate cat in which cough was elicited by direct electrical stimulation of the cough center. In this preparation dextromethorphan hydrobromide was compared to caramiphen as an antitussive agent. Dextromethorphan was somewhat more potent when given i.v. as well as when given directly into the left vertebral artery (i.a.). Both agents were far more effective when given i.a. than when given i.v. The effective dose ratios of i.v./i.a. were about 12 and 14 for caramiphen and 11 and 7 for dextromethorphan (actual and cumulative doses). These ratios indicate that both agents have a central rather than a peripheral site of antitussive action. Both drugs had antitussive effects in i.a. doses which did not alter arterial blood pressure or respiration greatly. However, after i.v. administration transient changes in both arterial blood pressure and respiration were observed with both agents. It was concluded that the antitussive action of both caramiphen and dextromethorphan is due to a selective effect on the cough center in the brainstem of the cat. On a milligram per kilogram basis, caramiphen required a 3 to 4 times larger dose than dextromethorphan for equieffective antitussive effects.

Scopolamine, morphine, and brain-stem auditory evoked potentials in awake monkeys.

The effects of scopolamine and morphine sulfate on brain-stem auditory evoked potentials (BAEPs) were studied in 10 rhesus (Macaca mulatta) monkeys. Study drugs were given intravenously to unanesthetized animals and BAEPs recorded at 3-min and 30-min intervals after administration of 0.1 mg/kg and 0.32 mg/kg of scopolamine and 15 min after administration of 3.2 mg/kg morphine at the end of the experiment. No significant change in either latency or amplitude of different components of BAEPs was observed.