Long-term predictors of residual or recurrent cervical intraepithelial neoplasia 2-3 after treatment with a large loop excision of the transformation zone: a retrospective study.

OBJECTIVE: To assess the long-term risk factors predicting residual/recurrent cervical intraepithelial neoplasia (CIN 2-3) and time to recurrence after large loop excision of the transformation zone (LLETZ). DESIGN: Retrospective study. SETTING: Colposcopy clinic. POPULATION: 242 women with CIN 2-3 treated between 1996 and 2006 and followed up until June 2016. METHODS: Age, margins, and high-risk human papillomavirus (HR-HPV) were estimated using Cox proportional hazard and unconditional logistic regression models. The cumulative probability of treatment failure was estimated by Kaplan-Meier analysis. MAIN OUTCOME MEASURE: Histologically confirmed CIN 2-3, HR-HPV, margins, age. RESULTS: CIN 2-3 was associated with HR-HPV (HR = 30.5, 95% confidence interval [CI] = 3.80-246.20), age >35 years (HR = 5.53, 95% CI = 1.22-25.13), and margins (HR = 7.31, 95% CI = 1.60-33.44). HR-HPV showed a sensitivity of 88.8% and a specificity of 80%. Ecto+ /endocervical+ (16.7%), uncertain (19.4%) and ecto- /endocervical+ margins (9.1%) showed a higher risk of recurrence (odds ratio [OR] = 13.20, 95% CI = 1.02-170.96; OR = 15.84, 95% CI = 3.02-83.01; and OR = 6.60, 95% CI = 0.88-49.53, respectively). Women with involved margins and/or who were HR-HPV positive had more treatment failure than those who were HR-HPV negative or had clear margins (P-log-rank <0.001). CONCLUSIONS: HR-HPV and margins seem essential for stratifying post-LLETZ risk, and enable personalised management. Given that clear margins present a lower risk, a large excision may be indicated in older women to reduce the risk. TWEETABLE ABSTRACT: After LLETZ for CIN 2-3, recurrences appear more often in women with positive HR-HPV and involved margins and aged over 35.

Stochastic particle barcoding for single-cell tracking and multiparametric analysis.

This study presents stochastic particle barcoding (SPB), a method for tracking cell identity across bioanalytical platforms. In this approach, single cells or small collections of cells are co-encapsulated within an enzymatically-degradable hydrogel block along with a random collection of fluorescent beads, whose number, color, and position encode the identity of the cell, enabling samples to be transferred in bulk between single-cell assay platforms without losing the identity of individual cells. The application of SPB is demonstrated for transferring cells from a subnanoliter protein secretion/phenotyping array platform into a microtiter plate, with re-identification accuracies in the plate assay of 96±2%. Encapsulated cells are recovered by digesting the hydrogel, allowing subsequent genotyping and phenotyping of cell lysates. Finally, a model scaling is developed to illustrate how different parameters affect the accuracy of SPB and to motivate scaling of the method to thousands of unique blocks.

Fuel cell-powered microfluidic platform for lab-on-a-chip applications: Integration into an autonomous amperometric sensing device.

The present paper reports for the first time the integration of a microfluidic system, electronics modules, amperometric sensor and display, all powered by a single micro direct methanol fuel cell. In addition to activating the electronic circuitry, the integrated power source also acts as a tuneable micropump. The electronics fulfil several functions. First, they regulate the micro fuel cell output power, which off-gas controls the flow rate of different solutions toward an electrochemical sensor through microfluidic channels. Secondly, as the fuel cell powers a three-electrode electrochemical cell, the electronics compare the working electrode output signal with a set reference value. Thirdly, if the concentration measured by the sensor exceeds this threshold value, the electronics switch on an integrated organic display. This integrated approach pushes forward the development of truly autonomous point-of-care devices relying on electrochemical detection.

Dielectrophoresis as a tool to characterize and differentiate isogenic mutants of Escherichia coli.

In this study we report on an experimental method based on dielectrophoretic analysis to identify changes in four Escherichia coli isogenic strains that differed exclusively in one mutant allele. The dielectrophoretic properties of wild-type cells were compared to those of hns, hha, and hha hns mutant derivatives. The hns and hha genes code respectively for the global regulators Hha and H-NS. The Hha and H-NS proteins modulate gene expression in Escherichia coli and other Gram negative bacteria. Mutations in either hha or hns genes result in a pleiotropic phenotype. A two-shell prolate ellipsoidal model has been used to fit the experimental data, obtained from dielectrophoresis measurements, and to study the differences in the dielectric properties of the bacterial strains. The experimental results show that the mutant genotype can be predicted from the dielectrophoretic analysis of the corresponding cultures, opening the way to the development of microdevices for specific identification. Therefore, this study shows that dielectrophoresis can be a valuable tool to study bacterial populations which, although apparently homogeneous, may present phenotypic variability.