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Early experience with a novel multielectrode saline-irrigated radiofrequency balloon (RFB) catheter with an integrated camera system found that it was safe and effective in performing single-shot pulmonary vein isolation (PVI) for atrial fibrillation.The purpose of this study was to further assess potential treatment risks by looking for subclinical events.The study was performed at 2 sites. Patients underwent PVI by RFB. A control group underwent conventional point-by-point radiofrequency ablation. Stroke scale questionnaire and brain magnetic resonance imaging (MRI) were performed before and after the ablation procedure, and esophageal endoscopy was performed after the procedure in RFB patients only.We enrolled 27 patients in the RFB group and 15 patients in the control group. The RFB and control groups were well matched [predominantly male: 62% vs 53%; CHAAn increased rate of clinically silent cerebral events was seen in the RFB group. A low rate of esophageal thermal injury was observed.

Background: Catheter ablation for atrial fibrillation has potential to cause esophageal thermal injury. Esophageal temperature monitoring during ablation is commonly used; however, it has not eliminated thermal injuries, possibly because conventional sensors have poor spatial sampling and response characteristics. To enhance understanding of temperature dynamics that may underlie esophageal injury, we tested a high-resolution, intrabody, infrared thermography catheter to continuously image esophageal temperatures during ablation. Methods and Results: Atrial fibrillation ablation patients were instrumented with a flexible, 9F infrared temperature catheter inserted nasally (n=8) or orally (n=8) into the esophagus adjacent to the left atrium. Ablation was performed while the infrared catheter continuously recorded surface temperatures from 7680 points per second circumferentially over a 6-cm length of esophagus. Physicians were blinded to temperature data. Endoscopy was performed within 24 hours to document esophageal injury. Thermal imaging showed that most patients (10/16) experienced ≥1 events where peak esophageal temperature was >40°C. Three patients experienced temperatures >50°C; and 1 experienced >60°C. Analysis of temperature data for each subject’s maximum thermal event revealed high gradients (2.3±1.4°C/mm) and rates of change (1.5±1.3°C/s) with an average length of esophageal involvement of 11.0±5.4 mm. Endoscopy identified 3 distinct thermal lesions, all in patients with temperatures >50°C; all resolved within 2 weeks. Conclusions: Infrared thermography provided dynamic, high-resolution mapping of esophageal temperatures during cardiac ablation. Esophageal thermal injury occurred with temperatures >50°C and was associated with large spatiotemporal gradients. Additional studies are warranted to determine the relationships between thermal parameters and esophageal injury.

In his entry on fathers in De Proprietatibus Rerum (ca. 1240), Bartholomaeus Anglicus writes: “He loves most the son that is most like him and often observes and watches over him. He gives his children clothing and food and drink appropriate to their age. He purchases land and provides an inheritance for his children, and makes sure it increases. He tills the land and leaves it to his heirs.”1 Moving away from the more abstract scientific discourse on the father’s role in procreation that begins the entry, which he attributes to constantine and Aristotle, Bartholomaeus grounds his depiction of fatherhood in affect, provision, and inheritance. At the same time, he observes that a father’s actions are guided by the order of his children’s birth and how much they appear to resemble him. These themes are taken up again toward the end of the entry

Studies have suggested that a colonoscopy withdrawal time of at least 6 minutes is associated with an increased adenoma detection rate in patients undergoing colorectal cancer screening.We aimed to determine colonoscopy withdrawal time and rate of polyp detection in a blinded study--conducted at Christchurch Hospital (Christchurch, New Zealand)--to determine if there was a relationship.All 16 consultant endoscopists performing colonoscopy in a tertiary hospital had their withdrawal time from the caecum prospectively timed over 208 consecutive procedures between 11 April 2007 and 19 May 2007. The following data was collected: indication for procedure, final diagnosis, polypectomy rate, procedures performed and withdrawal time were recorded. Histology results were reviewed for all patients.111 (53%) of colonoscopies were performed for symptom assessment and 97 (47%) for surveillance. There was significant heterogeneity between colonoscopists' withdrawal times (p0.001). Polyps were diagnosed in 65 of all colonoscopies (31.3%). Of the screening colonoscopies polyps were found in 38 (39.1%) of which 14 were adenomas (adenoma detection rate of 14%). The median colonoscopy withdrawal time was 3 minutes 16 seconds when no polyps were found (range 5 seconds to 11 minutes 50 seconds). The median colonoscopy time when polyps were found was 8 minutes 31 seconds which included time taken for procedures (range 2 minutes 7 seconds to 35 minutes 40 seconds), p0.001.This study confirms that more adenomas were found by those endoscopists who had slower withdrawal times. Also colonoscopy withdrawal times are inherently much faster than recommended and highlights the importance of regular adenoma detection rate and withdrawal time auditing.

The preparation by total synthesis of a new class of β-lactam antibiotics is reported. Conversion of alcohol 1b to its mesylate 9b followed by hydrolysis of the acetal to the enol 1b and base-catalyzed ring closure gave benzyl 7- β-azido-Δ3-O-2-isocephem-4-carboxylate 8b. Similarly prepared were the 3 -methyl, 3 -benzyl, and 3 -phenethyl analogs (32b–d). Reduction of the azides followed by coupling of the resultant amines with phenoxyacetic acid and removal of the benzyl groups by hydrogenolysis gave the acids 35a–e which exhibited high antibacterial activity. The structural assignments to the O-2-isocephems which were made on the basis of their spectral characteristics (ir, uv, and nmr) are discussed.

Treatment of the acid 3 with triethylamine in refluxing tert-butyl alcohol gave the decarboxylated product 4 which was isomerized to the desired Δ3 isomer 5 using DBN. Reduction of the azido functions in 4 and 5 followed by coupling to phenoxyacetic acid and debenzylation gave the acids 11 and 8, respectively. Attempts to prepare dienic cephalosporins failed. The halogenation of 4 and 5 was studied and is discussed.

The syntheses of the desthiocephem system from the enol 2 is described. Thus conversion of 2 to its triflate 3 followed by treatment with the sodium salts of malonate esters gave the cyclized products 4a–c. Azide reduction followed by coupling of phenoxyacetic acid and hydrogenolysis gave the acids 7 and 8. Compound 15 was also prepared.

The general synthetic scheme to nuclear analogs of cephalosporins described in previous papers of this series is reviewed and the synthesis of a series of sidechain derivatives is given. Thus, systems of the following type were formed: carbacephems (A), 2-isocephems (B), N-2-isocephems (C), and O-2-isocephems (D). The invitro microbiological activity of these compounds (with appropriate side-chains attached) is given, with comparison to analogous cephalosporins. Systems of type A, B, and C were only prepared with a 3-H or CH3 substituent and had modest antibacterial activity. The O-2-isocephems (D) were prepared with a wide variety of sidechains at 3 and 7 and were found to have biological activity quite comparable to the cephalosporins. A more detailed biological examination (both invitro and invivo) of the O-2-isocephem analog (19i) of cephalothin was made.

The synthesis of 7β-(-2′-thienylacetamido)-3-acetoxymethyl-Δ3-O-2-isocepheni-4-carboxylic acid (17) is described. Thus treatment of enol mesylate 3a or triflate 3b with triethylamine gave the allene 4 which gave the diiodide upon treatment with iodine. The diiodide gave benzyl 7β-azido-3-acetoxymethyl-Δ3-O-2-isocephem-4-carboxylate (12) on treatment with potassium acetate in DMF. Hydrogenolysis of 12 gave the amino acid 16 which was converted to 17 upon treatment with 2-thienylacetyl chloride. Resolution of 17 into its optical antipodes was carried out. The antibiotic activities of racemic 17 and each antipode is compared to that of cephalothin. Antibiotic activity was found to reside in the dextrorotatory isomer.