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Background: Prior to attempting placement of one or more electrodes to revise existing rhythm control devices, patency of the central veins should be documented, in view of a high incidence of significant chronic occlusions. Since iodinated contrast venography may be contraindicated in select situations, imaging of the axillo-subclavian venous system with gaseous carbon dioxide (CO(2)) was evaluated prospectively in 23 consecutive individuals who were considered for revision of previously implanted pacemaker or automatic cardioverter defibrillator lead systems. Methods: Approximately 20 mL of CO(2) were manually infused via CO(2) primed injection tubing into a vein at or above the level of the antecubital fossa ipsilateral to the side of prior lead placements. Digital subtraction imaging over the axillo-subclavian region, lower neck, and mediastinum was performed. Formal interpretation was obtained from one of three interventional radiologists and at least one electrophysiologist. Results: Significant venous occlusions were identified in five (22%) patients. Vascular access utilized for the subsequent 18 revisions performed included the imaged patent ipsilateral vein in 14 patients and the contralateral, right-sided subclavian venous system in three patients. One patient required epicardial left ventricular lead placement. There were no complications from venography. Conclusions: Axillo-subclavian venography with gaseous CO(2) in patients undergoing pacemaker or implantable cardioverter defibrillator lead revisions is feasible and safe when use of iodinated dye is contraindicated. This technique should be employed in patients with azotemia, dye contrast allergies, or significant inflammation in the vicinity of the intravenous line insertion. [ABSTRACT FROM AUTHOR]

Research participants' views about investigator financial interests were explored. Reactions ranged from concern to acceptance, indifference, and even encouragement. Although most wanted such information, some said it did not matter, was private, or was burdensome, and other factors were more important to research decisions. Very few said it would affect their research decisions, and many assumed that institutions managed potential conflicts of interest. Although disclosure of investigator financial interest information to research participants is often recommended, its usefulness is limited, especially when participation is desired because of illness. [ABSTRACT FROM AUTHOR]

The potent human toxicity of organophosphorus (OP) nerve agents calls for the development of effective antidotes. Standard treatment for nerve agent poisoning with atropine and an oxime has a limited efficacy. An alternative approach is the development of catalytic bioscavengers using OP-hydrolyzing enzymes such as paraoxonases (PON1). Recently, a chimeric PON1 mutant, IIG1, was engineered toward the hydrolysis of the toxic isomers of soman and cyclosarin with high in vitro catalytic efficiency. In order to investigate the suitability of IIG1 as a catalytic bioscavenger, an in vivo guinea pig model was established to determine the protective effect of IIG1 against the highly toxic nerve agent cyclosarin. Prophylactic i.v. injection of IIG1 (1 mg/kg) prevented systemic toxicity in cyclosarin (~2LD50)-poisoned guinea pigs, preserved brain acetylcholinesterase (AChE) activity, and protected erythrocyte AChE activity partially. A lower IIG1 dose (0.2 mg/kg) already prevented mortality and reduced systemic toxicity. IIG1 exhibited a high catalytic efficiency with a homologous series of alkylmethylfluorophosphonates but had low efficiency with the phosphoramidate tabun and was virtually ineffective with the nerve agent VX. This quantitative analysis validated the model for predicting in vivo protection by catalytic bioscavengers based on their catalytic efficiency, the level of circulating enzyme, and the dose of the intoxicating nerve agent. The in vitro and in vivo results indicate that IIG1 may be considered as a promising candidate bioscavenger to protect against the toxic effects of a range of highly toxic nerve agents.

Object: Research suggests that there may be a growing disparity between the supply of and demand for both pediatric specialists and neurosurgeons. Whether pediatric neurosurgeons are facing such a disparity is disputable, but interest in pediatric neurosurgery (PNS) has waxed and waned as evidenced by the number of applicants for PNS fellowships. The authors undertook a survey to analyze current neurosurgical residents' perceptions of both benefits and deterrents to a pediatric neurosurgical career., Methods: All residents and PNS fellows in the United States and Canada during the academic year 2008-2009 were invited to complete a Web-based survey that assessed 1) demographic and educational information about residents and their residency training, particularly as it related to training in PNS; 2) residents' exposure to mentoring opportunities from pediatric neurosurgical faculty and their plans for the future; and 3) residents' perceptions about how likely 40 various factors were to influence their decision about whether to pursue a PNS career., Results: Four hundred ninety-six responses were obtained: 89% of the respondents were male, 63% were married, 75% were in at least their 3rd year of postgraduate training, 61% trained in a children's hospital and 29% in a children's "hospital within a hospital," and 72% were in programs having one or more dedicated PNS faculty members. The residencies of 56% of respondents offered 6-11 months of PNS training and nearly three-quarters of respondents had completed 2 months of PNS training. During medical school, 92% had been exposed to neurosurgery and 45% to PNS during a clinical rotation, but only 7% identified a PNS mentor. Nearly half (43%) are considering a PNS career, and of these, 61% are definitely or probably considering post-residency fellowship. On the other hand, 68% would prefer an enfolded fellowship during residency. Perceived strengths of PNS included working with children, developing lasting relationships, wider variety of operations, fast healing and lack of comorbidities, and altruism. Perceived significant deterrents included shunts, lower reimbursement, cross-coverage issues, higher malpractice premiums and greater legal exposure, and working with parents and pediatric health professionals. The intrinsic nature of PNS was listed as the most significant deterrent (46%) followed by financial concerns (25%), additional training (12%), longer work hours (12%), and medicolegal issues (4%). The majority felt that fellowship training and PNS certification should be recommended for surgeons treating of all but traumatic brain injuries and Chiari I malformations and performing simple shunt-related procedures, although they felt that these credentials should be required only for treating complex craniosynostosis., Conclusions: The nature of PNS is the most significant barrier to attracting residents, although reimbursement, cross-coverage, and legal issues are also important to residents. The authors provide several recommendations that might enhance resident perceptions of PNS and attract trainees to the specialty.

Background: Usefulness of 12-lead ECG for predicting an epicardial origin for ventricular tachycardia (VT) arising from the right ventricle (RV) has not been assessed. An epicardial approach is sometimes warranted to eliminate RV VT., Objectives: The purpose of this study was investigate the hypothesis that specific ECG features identify an epicardial origin for RV VT., Methods: To mimic an endocardial or epicardial origin, we paced representative sites in 13 patients undergoing RV endocardial/epicardial mapping (134/180 pace map sites)., Results: QRS duration from epicardial vs endocardial sites was not different (183 +/- 27 ms vs 185 +/- 28 ms, P = .3). Reported cut-off values for identifying epicardial left ventricular origin, pseudo-delta wave (> or =34 ms), intrinsicoid deflection time (> or =85 ms), and RS complex (> or =121 ms) did not apply to the RV. A Q wave in lead II, III, or aVF was more likely noted from inferior epicardial vs endocardial sites (53/73 vs 16/43, P <.01). A Q wave in lead I was more frequently present from epicardial vs endocardial anterior RV sites (30/82 vs 5/52, P <.001). QS in lead V(2) was noted from anatomically matched epicardial anterior RV sites (22/33 vs 13/33, P <.05). In the RV outflow tract, no ECG feature distinguishing epicardial/endocardial origin reached statistical significance., Conclusion: A Q wave or QS in leads that best reflect local activation suggest an epicardial origin for RV depolarization and may help in identifying a probable epicardial site of origin for RV VT. QRS duration and reported criteria for epicardial origin of VT in the left ventricle do not identify a probable epicardial origin in the RV.

Objective: To evaluate the effect of increasing LV pacing output on interventricular timing in patients with biventricular pacing systems., Background: Clinical improvement with biventricular pacing is likely related to reduction in ventricular dysynchrony in patients with cardiomyopathy. We hypothesized that increasing left ventricular pacing output would reduce interventricular conduction time and could affect ventricular synchrony., Methods: Forty-two sequential patients with biventricular pacing systems that permitted independent LV pacing were selected at the time of routine device interrogation. The interval between LV pacing stimulus and onset of the RV electrogram was measured during LV pacing at capture threshold and at maximum pacing output for each patient., Results: The average time from LV pacing stimulus to right ventricular electrogram onset was 142.5 +/- 32.5 ms (range 90-230 ms) at threshold and 132.3 +/- 30.4 ms (range 90-220 ms) at maximum pacing output, with a mean decrease in conduction time of 10.2 +/- 10.9 ms (range 0-45 ms). There was significantly greater interventricular conduction shortening with increased pacing output in patients with ischemic cardiomyopathy compared to others (14.9 +/- 11.9 ms vs 4.0 +/- 4.6 ms; P < 0.01)., Conclusions: Conduction time from LV to RV shortens as LV pacing output is increased. This effect is seen to a greater degree in patients with ischemic cardiomyopathy, possibly related to the presence of myocardial scar near the pacing electrode. Further investigation is needed to assess the clinical outcomes related to this new method for optimizing resynchronization therapy.

Colchicine is a commonly used drug for the treatment of gout and other indications. Toxicity from intentional oral overdoses of colchicine has been reported. Two cases are reported here in which colchicine was given by intravenous injection, and patients presented with multiorgan toxicity. The authors tested plasma and urine colchicine levels in these patients and found them significantly elevated. Testing of the vial from which the colchicine injections were given showed that the vial was mislabeled and contained 10-fold greater concentration of drug than the labeling indicated. These patients thus received a bolus dose of 20 mg of intravenous colchicine rather than the intended 2-mg dose. An intravenous dose of this magnitude has not previously been reported.

Objective: To compare the efficacy of several fixation techniques in the reconstruction of diastasis of the symphysis pubis in bladder exstrophy., Materials and Methods: The symphysis of 32 pelves removed from piglets about 1 month old were disrupted and repaired using one of eight methods. After repair, each pelvis was tested biomechanically for load-to-failure, stiffness and energy-to-failure. The various repair techniques were compared with one another and to a group of six pelves tested intact., Results: Four of the methods tested, including a #2 nylon suture placed through bone in a horizontal mattress arrangement, several loops of #2 nylon suture tied around the pubes, Mersilene tape tied around the pubes, and Mitek G-II suture anchors placed into the superior pubic rami, showed the highest stiffness and load-to-failure. All methods were very weak compared with the intact symphysis; the best load-to-failure (#2 nylon horizontal mattress suture) was less than half of that for intact bone, and the best stiffness (mersilene tape) was less than one-third that for the intact symphysis., Conclusion: The repairs varied greatly in the variables tested and those which are most promising merit further investigation to assess methods of improving their performance.