Retrospective Analysis of the Role of Antibiotic Prophylaxis in the Placement and Replacement of Percutaneous Nephrostomy Catheters in Patients with Malignant Ureteral Obstruction.

Background: Antibiotic prophylaxis is usually adopted to prevent urinary tract infection (UTI) after nephrostomy catheter placement and replacement. This prophylaxis has been little studied in cancer patients, and its efficacy is uncertain. Objective: To determine the rate of UTI associated with percutaneous nephrostomy catheters placement and replacement and associated risk factors. Methods: This retrospective study collected data from the available medical records. Catheter-related UTI was defined as any diagnosis of UTI based on clinical symptoms recorded in antibiotic prescription charts, and on the results of urine culture collected up to 7 days after percutaneous nephrostomy catheter. The associations between categorical variables were analyzed using Fisher's exact test. The risk factors for UTI were assessed using logistic regression. Results: In the univariate analyses, there was no significant difference in the rate of urinary infection between patients receiving and not receiving antibiotic prophylaxis before percutaneous nephrostomy and after replacement. Conclusion: The results of the present study suggest that the use of antibiotic prophylaxis for managing urinary tract obstruction by percutaneous nephrostomy is not recommended in cancer patients. In contrast, for catheter replacement, antibiotic prophylaxis appears to have a protective effect for UTI.

A mobile-phone based high-resolution microendoscope to image cervical precancer.

Nearly 90% of cervical cancer cases and deaths occur in low- and middle-income countries that lack comprehensive national HPV immunization and cervical cancer screening programs. In these settings, it is difficult to implement screening programs due to a lack of infrastructure and shortage of trained personnel. Screening programs based on visual inspection with acetic acid (VIA) have been successfully implemented in some low-resource settings. However, VIA has poor specificity and up to 90% of patients receiving treatment based on a positive VIA exam are over-treated. A number of studies have suggested that high-resolution cervical imaging to visualize nuclear morphology in vivo can improve specificity by better distinguishing precancerous and benign lesions. To enable high-resolution imaging in low-resource settings, we developed a portable, low-cost, high-resolution microendoscope that uses a mobile phone to detect and display images of cervical epithelium in vivo with subcellular resolution. The device was fabricated for less than $2,000 using commercially available optical components including filters, an LED and triplet lenses assembled in a 3D-printed opto-mechanical mount. We show that the mobile high-resolution microendoscope achieves similar resolution and signal-to-background ratio as previously reported high-resolution microendoscope systems using traditional cameras and computers to detect and display images. Finally, we demonstrate the ability of the mobile high-resolution microendoscope to image normal and precancerous squamous epithelium of the cervix in vivo in a gynecological referral clinic in Barretos, Brazil.