Cellular effects of acute exposure to high peak power microwave systems: Morphology and toxicology.

Electric fields produced by advanced pulsed microwave transmitter technology now readily exceed the Institute of Electrical and Electronic Engineers (IEEE) C.95.1 peak E-field limit of 100 kV/m, highlighting a need for scientific validation of such a specific limit. Toward this goal, we exposed Jurkat Clone E-6 human lymphocyte preparations to 20 high peak power microwave (HPPM) pulses (120 ns duration) with a mean peak amplitude of 2.3 MV/m and standard deviation of 0.1 with the electric field at cells predicted to range from 0.46 to 2.7 MV/m, well in excess of current standard limit. We observed that membrane integrity and cell morphology remained unchanged 4 h after exposure and cell survival 24 h after exposure was not statistically different from sham exposure or control samples. Using flow cytometry to analyze membrane disruption and morphological changes per exposed cell, no changes were observed in HPPM-exposed samples. Current IEEE C95.1-2005 standards for pulsed radiofrequency exposure limits peak electric field to 100 kV/m for pulses shorter than 100 ms [IEEE (1995) PC95.1-Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic and Electromagnetic Fields, 0 Hz to 300 GHz, Institute of Electrical and Electronic Engineers: Piscataway, NJ, USA]. This may impose large exclusion zones that limit HPPM technology use. In this study, we offer evidence that maximum permissible exposure of 100 kV/m for peak electric field may be unnecessarily restrictive for HPPM devices. Bioelectromagnetics. 37:141-151, 2016. © 2016 Wiley Periodicals, Inc.

Controversy in colposcopic management: a Canadian survey.

OBJECTIVE: The substantial reduction in cervical cancer mortality over the last 40 years is attributed to the use of Papanicolaou cervical smear screening with subsequent colposcopic assessment and treatment. Although there is consensus regarding colposcopic management of high-grade intraepithelial cervical lesions, optimal management of patients with low-grade (LG) lesions is less clear. Our goal was to document the colposcopic management of the latter group in Canada. METHODS: A survey was mailed to 252 colposcopists in seven Canadian provinces who recommended management for colposcopy scenarios. Responses were reported in aggregate form. RESULTS: A total of 120/252 (48%) completed questionnaires. Most respondents were 41 to 50 years old, and 68% were male. For women found on colposcopy to have no evidence of a low-grade cervical LG lesion, 43% recommended discharge from colposcopy, and 53% recommended repeat colposcopy. For referrals with a biopsy-confirmed LG lesion, 13% recommended discharge to cytological follow-up, 65% recommended repeat colposcopy, and 16% recommended treatment. Following excisional treatment of LG lesions with negative margins, 13% recommended discharge to cytological follow-up, and 69% recommended further colposcopy. CONCLUSION: These results demonstrate wide variation in management of low-grade cervical lesions among Canadian colposcopists and highlight the need to establish evidence-based management protocols.

Primary carcinoma of the rectovaginal septum diagnosed as uterine prolapse.

BACKGROUND: Primary carcinoma of the rectovaginal septum is very rare. Most cases are associated with documented endometriosis, and patients will often present with vaginal or rectal bleeding. CASE: A 47-year-old woman presented to the emergency department complaining of urinary symptoms and "something falling out of the vagina." She was diagnosed initially as having uterine prolapse. However, further investigations and surgery showed that she had a primary papillary serous carcinoma of the rectovaginal septum, and the carcinoma later metastasized to the lymph nodes. No evidence of endometriosis was found. Assessment and subsequent treatment of this aggressive tumour was likely delayed because of its initial benign presentation. CONCLUSION: Our presentation of the case of a woman with primary carcinoma of the rectovaginal septum not associated with a focus of endometriosis shows that this rare aggressive cancer may present in a clinically benign fashion.

Quantitation of basal dyssynchrony and acute resynchronization from left or biventricular pacing by novel echo-contrast variability imaging.

OBJECTIVES: This study sought to test a novel echocardiographic method based on contrast variability imaging (CVI), to quantify cardiac dyssynchrony and magnitude of resynchronization achieved by left ventricular (LV) and biventricular (BiV) pacing therapy. BACKGROUND: Left ventricular or BiV pacing is a promising new therapy for patients with heart failure and intraventricular conduction delay. However, precise quantitation of the extent of resynchronization achieved remains scant. METHODS: Ten patients treated with BiV or LV pacing therapy were studied. Echo-contrast was infused slowly, and gated images were acquired before and during contrast appearance. The temporally normalized variance derived from 30 to 50 sequential beats was determined at each pixel to yield the CVI image-displaying improved wall delineation. Systolic regional fractional area of radial sectors was calculated with active and temporarily suspended (AAI) pacing. All analyses were performed blinded to both patient and treatment. RESULTS: Pacing increased septal inward motion from -20.4 +/- 9.6% to -30.5 +/- 14.0%, whereas lateral wall motion occurred earlier with no net magnitude change. Both spatial and temporal dyssynchrony in the LV declined nearly 40% with LV or BiV pacing (p < or = 0.001), and this correlated with increasing ejection fraction (31% to 39%; p < 0.02; p < 0.004 for correlation with dyssynchrony). CONCLUSIONS: The new imaging and regional dyssynchrony analysis methods provide quantitative assessment of resynchronization analogous to that previously obtained only by tagged magnetic resonance imaging. This could provide a useful noninvasive method for both identifying candidates and following long-term therapy.