Sequential occurrence of life-threatening hypokalemia and rebound hyperkalemia associated with barbiturate coma therapy.

OBJECTIVE: To report a sequential occurrence of life-threatening hypokalemia and rebound hyperkalemia following barbiturate coma therapy. CASE HISTORY: A 53-year-old man was admitted to the division of nephrology due to sudden development of severe hypokalemia. The patient had been treated following a clinical diagnosis of traumatic subarachnoid hemorrhage and subdural hematoma. Barbiturate coma therapy had been performed on this patient. He developed fatal hypokalemia 10 hours after the start of thiopental administration which did not respond to potassium supplementation. The lowest potassium level following barbiturate coma therapy was 1.0 mmol/l. Severe bradycardia and cardiac arrest developed, which necessitated cardiac massage and treatment with epinephrine and atropine. He recovered from cardiac arrest. When thiopental infusion was suddenly stopped, the potassium level increased to 8.9 mmol/l, which required quick administration of calcium gluconate and infusion of glucose solution mixed with regular insulin. Despite such management, he developed asystole. After direct current cardioversion and emergency hemodialysis, he recovered from cardiac arrest and his serum potassium level was stabilized. CONCLUSION: We recommend that clinicians must be aware of the potential occurrence of severe hypokalemia, which is rare but fatal, following barbiturate coma therapy. Rebound hyperkalemia, which is fatal, may also occur following cessation of thiopental infusion. Clinicians should also be aware of this potential complication. Further studies are needed to elucidate the precise mechanism of this clinical event.

Cellular responses and proteomic analysis of Escherichia coli exposed to green tea polyphenols.

The purpose of this study was to characterize the cellular response and proteomic analysis of Escherichia coli exposed to tea polyphenols (TPP) extracted from Korean green tea (Camellia sinensis L). TPP showed a dose-dependent bactericidal effect on E. coli. Analysis of cell-membrane fatty acids of E. coli cultures treated with TPP identified unique changes in saturated and unsaturated fatty acids, whereas scanning electron microscopic analysis demonstrated the presence of perforations and irregular rod forms with wrinkled surfaces in cells treated with TPP. Two-dimensional polyacrylamide gel electrophoresis of soluble protein fractions from E. coli cultures exposed to TPP showed 17 protein spots increased or decreased by TPP. Nine upregulated proteins were identified (including GroEL and proteins involved in cellular defense, such as GyrA, RpoS, SodC, and EmrK), whereas the expression of eight proteins was downregulated by exposure to TPP (including proteins involved in carbon and energy metabolism, such as Eno, SdhA, and UgpQ, as well as those involved in amino-acid biosynthesis, such as GltK and TyrB). These results provide clues for understanding the mechanism of TPP-induced stress and cytotoxicity on E. coli.