Serum levels and urine detection of Centruroides sculpturatus venom in significantly envenomated patients.

INTRODUCTION: Envenomation by Centruroides sculpturatus can cause systemic signs and symptoms requiring treatment. The toxicokinetics of C. sculpturatus venom has not been described. METHODS: Venom components were separated for cross-reactivity testing. Serum and urine collected from three patients envenomated by C. sculpturatus had venom levels determined by sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: Western blot analysis indicated recognition of C. sculpturatus venom by Alacramyn, an equine F(ab')(2) antivenom developed against Centruroides scorpion venoms, including C. sculpturatus. Serum venom levels in ng/mL with post-envenomation times in minutes (min) were as follows: 85-year-old woman = 8.2 (approximately 150), 2.8 (515), 1.6 (1,200); 14-month-old girl = 29.7 (approximately 50), 5.0 (729); 3-year-old girl = 11.1 (approximately 313), urine venom level of 9.0 (approximately 490). CONCLUSION: There is sufficient venom cross-antigenicity among different Centruroides species to allow this ELISA technique with Alacramyn to determine serum and urine C. sculpturatus venom concentrations in envenomated patients.

Epidemiology of organophosphate pesticide poisoning in Taiwan.

INTRODUCTION: The nationwide epidemiology of organophosphate pesticide (OP) poisoning has never been reported in detail for Taiwan. METHODS: This study retrospectively reviewed all human OP exposures reported to Taiwan's Poison Control Centers (PCCs) from July 1985 through December 2006. RESULTS: There were 4799 OP exposures. Most OP exposures were acute (98.37%) ingestions (74.50%) of a single OP (80.37%) to attempt suicide (64.72%) in adults (93.25%). Males were the most common gender (64.95%). Most patients (61.97%) received atropine and/or pralidoxime. The mortality rate for all 4799 OP exposures was 12.71%. Exposures to single OPs without co-intoxicants caused 524 deaths; of these, 63.36% were due to dimethyl OPs. CONCLUSION: Dimethyl OPs cause the majority of deaths in Taiwan.

Spectrophotometry of hydroxocobalamin and hemoglobin reveals production of an unanticipated methemoglobin variant.

INTRODUCTION: Cyanide-poisoned patients often require pulse oximetry and co-oximetry to measure oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, and methemoglobin. These and other critical laboratory measurements can be confounded by the cyanide antidote hydroxocobalamin. The postulated mechanism of this confounding is direct optical interference. METHODS: The spectra of swine hemoglobin with and without hydroxocobalamin were measured from 450-800 nm. The resulting complex spectrum was divided into hemoglobin, hydroxocobalamin, and a remainder spectrum. RESULTS: The remainder spectrum appears to be a methemoglobin variant quantitatively dependant on the amount of hydroxocobalamin added to the hemoglobin solution and the presence of oxygen. The Pearson's correlation coefficient comparing the known swine methemoglobin spectrum with the remainder spectrum reveals a very high degree of correlation (r(2) = 0.986). CONCLUSION. This is the first study to document methemoglobin formation caused by hydroxocobalamin. Further studies are needed in vitro and in vivo to assess this previously unreported methemoglobin variant.