Christian Ochoa

Alcoholism risk, tobacco smoking, and P300 event-related potential

OBJECTIVE The P300 event-related potential (ERP) is sometimes larger for individuals at low- compared to high-risk for alcoholism. These effects are inconsistent, and how P300 is affected by tobacco smoking in the context of alcoholism risk is unknown. The present study used P300 to examine the inter-relationship between alcoholism heritability and smoking status. METHODS P300 was elicited with a visual discrimination task from young adults at low- and high-risk for alcoholism. Half of the subjects in each risk category reported that they did not smoke cigarettes, and the other half reported that they smoked regularly, with equal numbers of male and female subjects assessed. ERPs were recorded, and subjects were instructed to respond only to an infrequently presented target stimulus that occurred in a series of standard and distracter stimuli. RESULTS P300 amplitude from the target stimuli was larger for the low-risk compared to high-risk subjects overall. However, smoking status demonstrated even stronger effects, with non-smokers producing consistently larger component amplitudes than smokers and accounting for more variance than alcoholism risk. These group factors also significantly affected P300 scalp topography. No reliable alcoholism risk or smoking group effects were obtained for the ERPs from the other stimuli. CONCLUSIONS The findings suggest that P300 measures of alcoholism risk in young adults are moderated by smoking status. Theoretical implications are discussed.

Peroxynitrite-induced p38 MAPK pro-apoptotic signaling in enterocytes.

Enterocyte apoptosis in necrotizing enterocolitis is partly due to the elaboration of toxic intermediates of nitric oxide (NO), such as peroxynitrite (PN). Because p38 mitogen-activated protein kinase (MAPK) and serine-threonine kinase (AKT) are well-characterized pro- and anti-apoptotic mediators, respectively, we hypothesized that PN could induce enterocyte apoptosis via activation of p38 and deactivation of AKT. To test this hypothesis, the rat intestinal cell line, IEC-6, was treated with PN. PN caused phosphorylation of p38, its upstream activator, MKK3/6, and downstream effector, transcription factor ATF-2. PN-induced apoptosis was inhibited by the p38 inhibitor, SB202190, and by p38 siRNA. PN decreased AKT phosphorylation; this effect was abrogated by pre-treatment with SB202190 or p38 siRNA. PN exposure also increased the activity of the protein phosphatase 2A (PP2A). These data demonstrate that PN-mediated apoptosis depends on the p38 pathway and that p38 mediates deactivation of AKT survival pathways possibly by the involvement of PP2A.

Thoracoscopic Repair of Neonatal Diaphragmatic Hernia

INTRODUCTION The use of minimally invasive surgery (MIS) in the neonatal population is increasing. Thoracoscopic intervention for congenital diaphragmatic hernia (CDH) is no exception. In this report, we describe our initial experience with thoracoscopic repair of left-sided diaphragmatic defects in neonates. MATERIALS AND METHODS We performed retrospective chart reviews on all neonates who underwent thoracoscopic repair of CDH between November 2004 and January 2008. Neonates that underwent thoracoscopic repair were physiologically stable with resolved pulmonary hypertension and minimal to moderate ventilatory support. They had no associated cardiac anomalies. RESULTS We identified 15 neonates with CDH who underwent thoracoscopic repair during the study period. Ten neonates underwent primary repair of the diaphragmatic defect. Five neonates with large defects required closure with a synthetic patch, which was placed thoracoscopically. The average operating room time was 134 minutes. There were no instances of intraoperative respiratory or cardiac instability. Three patients had a recurrence. One recurrence was seen after thoracoscopic patch repair. Two recurrences occurred following primary repair of left diaphragmatic hernias. There were no deaths. Follow-up has been 4-40 months. CONCLUSIONS Neonatal MIS for CDH should be limited to stable patients. The ideal candidate is the newborn without associated anomalies, not requiring extracorporeal membrane oxygenation, on minimal ventilatory support, and without evidence of pulmonary hypertension. It is technically possible to perform thoracoscopic repair with a patch.

Thoracic aortic stent-grafting for acute, complicated, type B aortic dissections.

BACKGROUND To report a single-center experience of aortic stent-grafting for the treatment of acute, complicated, type B aortic dissections. METHODS A retrospective review was conducted of the data obtained from all patients who underwent endovascular stent-grafting for acute, type B aortic dissection between 2006 and 2009. The primary and secondary endpoints were 30-day mortality and morbidity rates, respectively. RESULTS In all, 104 thoracic endovascular aortic aneurysm repairs were performed during the study period. Nine (8.6%) patients (six men; mean age: 65 years) underwent thoracic endovascular aortic aneurysm repair for acute, complicated, type B aortic dissections. Seven (78%) patients had uncontrolled hypertension on presentation. Visceral branch vessel involvement of the dissection was limited to the celiac axis origin in one patient with no evidence of visceral malperfusion. The indication for repair was aortic rupture in five patients, renal malperfusion in two, and persistent pain in the remaining two. Average time taken from presentation to surgery was 5.5 days. Two patients presenting with aortic ruptures had retrograde extension of the dissection that required replacement of the aortic valve and ascending aorta. The mean length of thoracic aorta covered was 21 cm. Complete coverage of the left subclavian artery was required in three patients and partial coverage in two. On completion angiogram, two type I endoleaks were detected, one of which was resolved by postoperative day 5. The 30-day mortality rate was 22%. One mortality was secondary to aortic rupture. The other mortality was due to multiorgan system failure. Seven patients (78%) had one or more major complications. There were no strokes or paraplegia. CONCLUSION The association of morbidity and mortality with endovascular stent-grafting for acute, complicated, type B aortic dissections is significant, which most likely reflects the lethal nature of the disease. The precise role of endovascular treatment in these patients remains to be defined.

Agreement among observers in the assignment of TransAtlantic Inter-Society Consensus classification and runoff score

OBJECTIVE Productive communication among clinical practitioners is essential if recommendations regarding practice are to exist. The durability of vascular procedures is often influenced by factors such as lesion classification and runoff quality. It is the purpose of this article to determine how reproducible these measures are in the hands of various specialists who deal extensively with peripheral arterial disease. METHODS The peripheral arteriograms of 100 patients undergoing percutaneous intervention were distributed to six specialists (three vascular surgeons, two interventional radiologists, and one interventional cardiologist). Each was provided with the reference document describing TASC II classification, Society for Vascular Surgery (SVS) runoff score, and simplified runoff score. With no further instruction, each individual was asked to assign each angiogram a TASC II class, SVS runoff score, and a simplified runoff score. Comparisons between the scores assigned were made using kappa statistic. RESULTS When using the simplified runoff score for grading peripheral arterial disease, there was excellent correlation among readers (k = 0.81; P = .001), even across different specialties. When using TASC II class to grade lesions, there was a greater degree of variation when compared with the simplified runoff score (k = 0.44; P < .05). Finally, there was poor correlation between readers when using the SVS runoff score (k = 0.10; P < .05) and the modified SVS runoff score (k = 0.26; P = .001). CONCLUSIONS Descriptors of clinical disease severity are not universally reproducible. The simplified runoff score is reproducible when interpreted by multiple readers across different specialties and can be used without further modification. The TASC II classification may need minor alterations in description to obtain good correlation among readers. Before the SVS runoff score can be universally adapted, it will need to be described in much better detail or significantly modified.

Early cannulation of bovine carotid artery grafts (Artegraft) after primary vascular access and fistula revision procedures

Objective: Tunneled dialysis catheter (TDC) use has been associated with increased infectious complications and mortality in hemodialysis‐dependent patients. Unfortunately, patients who undergo fistula revisions or creation of a new arteriovenous fistula frequently require a TDC during the postoperative period. Bovine carotid artery grafts (BCAGs) can be used as an early‐access dialysis conduit to reduce TDC dependence. This study describes the performance of BCAGs that were cannulated early (<3 days) after implantation and associated clinical outcomes. Methods: BCAGs were implanted in 63 consecutive dialysis‐dependent patients. Patients and dialysis centers were directly provided early cannulation instructions; 31 (49%) patients were cannulated early, and of the 31 patients cannulated early, 21 (68%) were cannulated during the first postoperative day. Early complications, primary patency, secondary patency, and TDC incidence were monitored through clinic visits, hospital records, and phone calls to dialysis centers. Results: The primary patency of BCAGs at 1 year in the early and late cannulation cohorts was 28% and 39%, respectively. The secondary patency of BCAGs at 1 year in the early and late cannulation cohorts was 74% and 77%, respectively. Early complications occurred in 11 (19%) patients who received a BCAG. There were no significant differences in complication rates between early and late cannulation patients. Of the 24 patients who underwent the operation without a pre‐existing TDC, only three (13%) required TDC placement during the 30‐day postoperative period. Conclusions: BCAGs can be cannulated early without increased complication rates or a negative impact on midterm patency. Early cannulation of BCAGs obviates the need for a TDC postoperatively in dialysis‐dependent patients undergoing primary vascular access or fistula revision procedures.