Objective To evaluate the anti-microbial effects of photodynamic therapy (PDT) on infected human teeth ex vivo. Materials and Methods Fifty-two freshly extracted teeth with pulpal necrosis and associated periradicular radiolucencies were obtained from 34 subjects. Twenty-six teeth with 49 canals received chemomechanical debridement (CMD) with 6% NaOCl and twenty-six teeth with 52 canals received CMD plus PDT. For PDT, root canal systems were incubated with methylene blue (MB) at concentration of 50 µg/ml for 5 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm2. The contents of root canals were sampled by flushing the canals at baseline and following CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFU). Partial characterization of root canal species at baseline and following CMD alone or CMD+PDT was performed using DNA probes to a panel of 39 endodontic species in the checkerboard assay. Results The Mantel-Haenszel chi-square test for treatment effects demonstrated the better performance of CMD+PDT over CMD (P=0.026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone (P=0.0003). Following CMD+PDT, 45 of 52 canals (86.5%) had no CFU as compared to 24 of 49 canals (49%) treated with CMD (canal flush samples). The CFU reductions were similar when teeth or canals were treated as independent entities. Post-treatment detection levels for all species were markedly lower for canals treated by CMD+PDT than were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17/22 (77.3%) and 15/29 (51.7%) of canals in the CMD and CMD+PDT group, respectively (P= 0.034). Conclusion Data indicate that PDT significantly reduces residual bacteria within the root canal system, and that PDT, if further enhanced by technical improvements, holds substantial promise as an adjunct to CMD.

Three-dimensional mapping combined with TEE shows potential for eliminating fluoroscopy use during catheter ablation.

Background and Objectives Photodynamic therapy (PDT) is increasingly being explored for treatment of oral infections. Here, we investigate the effect of PDT on human dental plaque bacteria in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles with a positive or negative charge and red light at 665 nm. Study Design/Materials and Methods Subgingival plaque samples were obtained from 14 patients with chronic periodontitis. Suspensions of plaque microorganisms from seven patients were sensitized with anionic, cationic PLGA nanoparticles (50 μg/ml equivalent to MB) or free MB (50 μg/ml) for 20 min followed by exposure to red light for 5 min with a power density of 100 mW/cm2. Polymicrobial oral biofilms, which were developed on blood agar in 96-well plates from dental plaque inocula obtained from seven patients, were also exposed to PDT as above. Following the treatment, survival fractions were calculated by counting the number of colony-forming units. Results The cationic MB-loaded nanoparticles exhibited greater bacterial phototoxicity in both planktonic and biofilm phase compared to anionic MB-loaded nanoparticles and free MB, but results were not significantly different (p>0.05). Conclusion Cationic MB-loaded PLGA nanoparticles have the potential to be used as carriers of MB for PDT systems.

Abstract. This paper describes a large case study that explores the applicability of ontology reasoning to problems in the medical domain. We investigate whether it is possible to use such reasoning to automate common clinical tasks that are currently labor intensive and error prone, and focus our case study on improving cohort selection for clinical trials. An obstacle to automating such clinical tasks is the need to bridge the semantic gulf between raw patient data, such as laboratory tests or specific medications, and the way a clinician interprets this data. Our key insight is that matching patients to clinical trials can be formulated as a problem of semantic retrieval. We describe the technical challenges to building a realistic case study, which include problems related to scalability, the integration of large ontologies, and dealing with noisy, inconsistent data. Our solution is based on the SNOMED CT R ontology, and scales to one year of patient records (approx. 240,000 patients).

It is possible to diagnose accurately complex CHD, including the pulmonary venous connections. When diagnosed prenatally, TAPVC carries a poor prognosis.

Objective. The purpose of this series is to describe the prenatal echocardiographic findings of vascular rings. Methods. The 3-vessel and trachea view consists of the axial view of the upper mediastinum. The normal left aortic arch appears as a V-shaped confluence of the ductus arteriosus and aortic arch, with the trachea situated posterior and to the right. No vessel should encircle the trachea. The diagnoses of vascular rings were made prenatally and were confirmed in all patients postnatally. Results. Six fetuses had diagnoses of vascular rings. The mean gestational age at diagnosis was 23.3 weeks (range, 18-31 weeks). The indications for fetal echocardiography were family history of congenital heart disease, echogenic focus in the left ventricle, and abnormal 4-chamber view. There were 2 fetuses with a double aortic arch; 3 fetuses with a right aortic arch, an aberrant left subclavian artery, and a left ductus arteriosus; and 1 with a right circumflex aortic arch with a left ductus arteriosus and an aberrant left subclavian artery. Two fetuses had associated structural cardiac defects, 1 with an unbalanced atrioventricular septal defect and trisomy 21 and the other with a double-outlet right ventricle, pulmonary atresia, and multiple other congenital anomalies. Conclusions. Vascular rings can be accurately diagnosed prenatally with recognition of a vascular structure that courses around the trachea and absence of the usual V-shaped relationship of the aortic and ductal arches. The color Doppler findings and the presence of a ductus arteriosus aid in identifying various components of the vascular ring.

We reviewed 22 cases of primary pediatric cardiac tumors followed at our institution from January 1981 through November 1997, analyzing them by subtype, age and manner of presentation, location, associated findings, interventions, and clinical course. Rhabdomyomas were the most common (11), followed by intrapericardial teratomas (2), myxomas (1), fibromas (1), hemangiomas (1), mesotheliomas (1), and rhabdomyosarcomas (1), with 4 undetermined tumors. The majority (77%) of tumors were diagnosed before the age of one year, including six prenatally. The most common presentations were murmurs (5), arrhythmias (5), and abnormal screening fetal ultrasound examinations (4). Tumors were located most frequently in the right ventricle (13) and left ventricle (7), with multiple tumors being present in 10 cases. Eight patients (36%) had associated arrhythmias or conduction abnormalities, and of the 11 patients with rhabdomyomas, tuberous sclerosis was diagnosed in 8. Eight patients underwent cardiac catheterization, including two for electrophysiologic study with radiofrequency ablation, and seven patients had complete or partial tumor resection. The follow-up period ranged from 2 months to 15 years, and there were 3 tumor-related deaths. Therefore, despite the benign histology of most primary pediatric cardiac tumors, there may be significant associated morbidity and occasional mortality. As echocardiographic techniques such as fetal ultrasonography have continued to improve, however, these cardiac tumors have increasingly been detected early before significant symptoms develop.

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