Clinical and histopathological outcome of cervical and chest MRI involving non-MRI-conditional cardiac pacemakers: a study using sheep models.

AIM: To examine the clinical and histopathological consequences of MRI in sheep implanted with non-MRI-conditional cardiac pacemakers. MATERIALS AND METHODS: Under general anesthesia, active fixation leads of two dual-chamber, non-MRI-conditional cardiac pacemakers (St. Jude Medical and Medtronic) were implanted either at the right ventricular apex or at the right atrium of two male sheep and connected to the V and A channels of the pacemakers, respectively. The generators were placed in cervical subcutaneous pockets. On day 5, both sheep underwent 1.5 T cervical and chest MRI with continuous electrocardiogram monitoring. Obtained sequences were T1-weighted (T1W), T2-weighted (T2W), T2-gradient echo and diffusion weighted (DW). The employed modes were OVO, VOO and VVI for one sheep and OAO, AOO and AAI for the other (unipolar and bipolar configuration of pacing and sensing for both). Battery impedance, pacing lead impedance, intrinsic amplitude and capture thresholds were checked at baseline and after each sequence, as well as 48 h after imaging. Histopathological examination of the cardiac tissue around the lead tip was performed 4 weeks post-imaging. RESULTS: No significant changes in device position or configuration were observed during or after MRI. Clinical outcome was uneventful in both sheep. Minor inflammatory and necrotic changes were reported after histopathological examination of the cardiac tissue around the lead tip. CONCLUSION: 1.5 T MRI of two implanted non-MRI-conditional pacemakers was found safe in terms of device configuration and stability, clinical outcome and cardiac tissue histopathological findings.

The yield and impact of pulmonologist-performed EUS-B-FNA of subdiaphragmatic lesions-an institutional experience.

INTRODUCTION: Pulmonologists can biopsy structures below the diaphragm using the convex curvilinear ultrasound bronchoscope via the esophagus (EUS-B). The literature with respect to the value of EUS-B, rapid on-site evaluation, and final diagnostic yield for structures below the diaphragm is limited. We review our institutional experience. MATERIALS AND METHODS: Our database was queried retrospectively for EUS-B fine needle aspirations (FNAs) from 2013 to 2021. All procedures involving EUS-B-FNA of subdiaphragmatic structures were selected for analysis. The following data elements were collected for each patient: age, gender, clinical indication, sample site, on-site adequacy (OSA), preliminary and final diagnoses, and sufficiency of cell block for ancillary studies. RESULTS: A total of 75 subdiaphragmatic sites were biopsied in 74 patients. Of which, 87% of samples subjected to rapid on-site evaluation were deemed to contain adequate material (OSA+). There were no false-positive OSAs. Six cases remained nondiagnostic at the final diagnosis. The final diagnostic yield (with cell block) was 92% (69/75 cases). Cell block was sufficient for immunohistochemistry or special stains in all applicable cases (n = 36). Molecular testing was requested for 11 cases and successful in 10 (91%). Sampling of subdiaphragmatic sites changed the stage in 67% (38/57) of lung cancer patients. CONCLUSIONS: Pulmonologists can perform EUS-B-FNA of subdiaphragmatic sites with high OSA and final diagnostic yield when assisted by cytopathologists. Strong correlations exist between OSA, cell block adequacy, and subsequent capacity to perform ancillary testing. EUS-B below the diaphragm can make an important contribution to the diagnosis of lung cancer, nonpulmonary malignancies, and other diseases.

Drosophila melanogaster as a Model System to Assess the Effect of Epstein-Barr Virus DNA on Inflammatory Gut Diseases.

The Epstein-Barr virus (EBV) commonly infects humans and is highly associated with different types of cancers and autoimmune diseases. EBV has also been detected in inflamed gastrointestinal mucosa of patients suffering from prolonged inflammation of the digestive tract such as inflammatory bowel disease (IBD) with no clear role identified yet for EBV in the pathology of such diseases. Since we have previously reported immune-stimulating capabilities of EBV DNA in various models, in this study we investigated whether EBV DNA may play a role in exacerbating intestinal inflammation through innate immune and regeneration responses using the Drosophila melanogaster model. We have generated inflamed gastrointestinal tracts in adult fruit flies through the administration of dextran sodium sulfate (DSS), a sulfated polysaccharide that causes human ulcerative colitis- like pathologies due to its toxicity to intestinal cells. Intestinal damage induced by inflammation recruited plasmatocytes to the ileum in fly hindguts. EBV DNA aggravated inflammation by enhancing the immune deficiency (IMD) pathway as well as further increasing the cellular inflammatory responses manifested upon the administration of DSS. The study at hand proposes a possible immunostimulatory role of the viral DNA exerted specifically in the fly hindgut hence further developing our understanding of immune responses mounted against EBV DNA in the latter intestinal segment of the D. melanogaster gut. These findings suggest that EBV DNA may perpetuate proinflammatory processes initiated in an inflamed digestive system. Our findings indicate that D. melanogaster can serve as a model to further understand EBV-associated gastroinflammatory pathologies. Further studies employing mammalian models may validate the immunogenicity of EBV DNA in an IBD context and its role in exacerbating the disease through inflammatory mediators.