The efficiency of the cytobrush and cotton swab in obtaining endocervical cells in smears taken after conization of the cervix

Cervical Stenosis: Previously Unrecognized Cause of False-Negative Human Papillomavirus Tests in Women Developing Cervical Cancer

OBJECTIVES

Cervical stenosis can jeopardize adequate posttreatment cytologic follow-up of patients treated for high-grade cervical intraepithelial lesions. An impact on human papillomavirus (HPV) testing has not been described.

MATERIALS AND METHODS

We describe 2 patients with cervical stenosis, followed by cytology and HPV co-testing after excisions of high-grade cervical intraepithelial lesions. Each had 1 or more co-test "double-negative" results. Hysterectomies revealed unexpected cervical carcinomas.

RESULTS

In case 1, an 80-year-old woman with complete cervical stenosis and earlier high-grade squamous dysplasia presented with abdominal pain, nausea, and an enlarged uterus. Attempted endometrial biopsy was unsuccessful. Cytology and HPV tests 9 months earlier were negative. Hysterectomy revealed a cervical squamous carcinoma. In case 2, a 40-year-old woman followed conservatively after excision of endocervical adenocarcinoma in situ had 5 follow-up cytology and HPV co-tests. All were HPV negative. Elective hysterectomy revealed cervical adenocarcinoma. Both carcinomas tested HPV positive.

CONCLUSIONS

Cervical stenosis in women developing cervical cancer can cause misleading sampling and false-negative HPV test results.

An integratable microfluidic cartridge for forensic swab samples lysis

Fully automated rapid forensic DNA analysis requires integrating several multistep processes onto a single microfluidic platform, including substrate lysis, extraction of DNA from the released lysate solution, multiplexed PCR amplification of STR loci, separation of PCR products by capillary electrophoresis, and analysis for allelic peak calling. Over the past several years, most of the rapid DNA analysis systems developed started with the reference swab sample lysate and involved an off-chip lysis of collected substrates. As a result of advancement in technology and chemistry, addition of a microfluidic module for swab sample lysis has been achieved in a few of the rapid DNA analysis systems. However, recent reports on integrated rapid DNA analysis systems with swab-in and answer-out capability lack any quantitative and qualitative characterization of the swab-in sample lysis module, which is important for downstream forensic sample processing. Maximal collection and subsequent recovery of the biological material from the crime scene is one of the first and critical steps in forensic DNA technology. Herein we present the design, fabrication and characterization of an integratable swab lysis cartridge module and the test results obtained from different types of commonly used forensic swab samples, including buccal, saliva, and blood swab samples, demonstrating the compatibility with different downstream DNA extraction chemistries. This swab lysis cartridge module is easy to operate, compatible with both forensic and microfluidic requirements, and ready to be integrated with our existing automated rapid forensic DNA analysis system. Following the characterization of the swab lysis module, an integrated run from buccal swab sample-in to the microchip CE electropherogram-out was demonstrated on the integrated prototype instrument. Therefore, in this study, we demonstrate that this swab lysis cartridge module is: (1) functionally, comparable with routine benchtop lysis, (2) compatible with various types of swab samples and chemistries, and (3) integratable to achieve a micro total analysis system (μTAS) for rapid DNA analysis.