A remarkable diversity of bioactive lipophilic alkaloids is present in the skin of poison frogs and toads worldwide. Originally discovered in neotropical dendrobatid frogs, these alkaloids are now known from mantellid frogs of Madagascar, certain myobatrachid frogs of Australia, and certain bufonid toads of South America. Presumably serving as a passive chemical defense, these alkaloids appear to be sequestered from a variety of alkaloid-containing arthropods. The pumiliotoxins represent a major, widespread, group of alkaloids that are found in virtually all anurans that are chemically defended by the presence of lipophilic alkaloids. Identifying an arthropod source for these alkaloids has been a considerable challenge for chemical ecologists. However, an extensive collection of neotropical forest arthropods has now revealed a putative arthropod source of the pumiliotoxins. Here we report on the presence of pumiliotoxins in formicine ants of the genera Brachymyrmex and Paratrechina, as well as the presence of these ants in the stomach contents of the microsympatric pumiliotoxincontaining dendrobatid frog, Dendrobates pumilio. These pumiliotoxins are major alkaloids in D. pumilio, and Brachymyrmex and Paratrechina ants now represent the only known dietary sources of these toxic alkaloids. These findings further support the significance of ant-specialization and alkaloid sequestration in the evolution of bright warning coloration in poison frogs and toads.allomones ͉ allopumiliotoxins ͉ cardiotonic activity ͉ chemical defense ͉ myrmicine ants

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Obscure overt gastrointestinal bleeding (OGIB) is a challenge in patients with left ventricular assist devices (LVADs). We evaluated the utility and safety of double-balloon enteroscopy (DBE) in patients with LVADs in an observational consecutive-patient cohort from a single tertiary referral center. Ten patients with LVADs underwent thirteen DBEs for obscure OGIB. The first OGIB event necessitating DBE occurred after a mean of 512 ± 363 days of LVAD support. All patients underwent DBE, eleven anterograde and two retrograde, with a mean insertion depth 176 ± 85 cm. Diagnostic yield was 69 % with the primary bleeding lesion most frequently found in the mid-bowel. The most common lesions were arteriovenous malformations. Therapeutic yield with argon plasma coagulation (APC), epinephrine injection, and/or hemoclip placement was 89 %. There were no procedure-related complications. DBE in patients with LVADs has good diagnostic yield and high therapeutic yield for obscure OGIB and is safe and well tolerated.

Primary percutaneous coronary intervention (PCI) has emerged as the standard of care for the management of ST-elevation myocardial infarctions (STEMI). Only 32% of patients with STEMI receive this procedure within the recommended 90 min for door-to-balloon time (DTB). We reviewed all STEMI cases that presented to our institution before and after the implementation of a STEMI Code protocol. Before the STEMI Code protocol, 27.1% of weekday cases and 6.3% of weekend cases were performed within 90 min. After the STEMI Code protocol, there was a threefold increase in the number of patients who received PCI within 90 min (p<.0001). A STEMI Code protocol dramatically improves DTB and equalizes disparities between weekday and weekend care.

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Gastrointestinal bleeding (GIB) is common in patients with continuous-flow left ventricular assist devices (CF-LVADs) possibly because of changes in blood flow. We aimed to test the hypothesis that a low pulsatility index (PI) is associated with an increased hazard of overt GIB in patients with CF-LVADs. We conducted a retrospective cohort study of patients who had a HeartMate II (HMII) CF-LVAD implanted at our center. The study end-point was the first overt GIB causing or occurring during a hospitalization between 6 days and 6 months after HMII implantation. HMII PI was recorded at 48 hours and at 1, 3, and 6 month intervals after implantation. We analyzed the associations of PI and clinical variables with the hazard of overt GIB. Ninety-five patients met eligibility criteria. PI ranged from 2.5 to 5.9 (low PI < 4.15 and high PI ≥ 4.15 on the basis of receiver operating characteristic curve analysis). Seventeen (18%) patients experienced overt GIB. In a multivariable model, only lower baseline hemoglobin was a significant predictor of an increased hazard of overt GIB. After adjusting for the baseline hemoglobin, low PI was independently associated with an increased hazard of overt GIB in our cohort of HMII recipients.

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