Calibration of the Becton Dickinson FocalPoint GS slide profiler is essential for optimal performance: Avoiding the algorithm supersaturation cascade effect pitfall

BACKGROUND

The MAVARIC study supported the use of the FocalPoint GS (FPGS) imaging system "No Further Review" (NFR) technology for cervical screening and recommended further investigation. A validation study (Nuttall et al.) was performed by Cervical Screening Wales before implementing the NFR slide reporting technology within the cervical screening program in Wales, United Kingdom.

METHOD

A total of 45,317 SurePath liquid-based cytology cervical screening samples were submitted for FPGS scanning within four Welsh cytology laboratories between 2006 and 2011. The study, Computer Assisted Evaluation, Screening and Reporting, involved scanning the slides using the FPGS and comparing the results with manual screening performed under established Cervical Screening Wales protocols.

RESULTS

An increased number of abnormal cases presented in the NFR reporting category, significantly greater than that previously encountered. This anomaly resulted in higher false-negative rates with potentially life-changing consequences for the screening participant. Subsequent investigation determined that this increase in cases created an algorithm cascade or "sump" effect, which resulted in an unprecedented increased number of samples categorized as NFR. This exceeded the calibration parameters set for the FPGS and was thought to be caused by an increase in the number of younger women attending for screening following the death of a young reality television celebrity from cervical cancer.

CONCLUSION

Adequate and timely calibration of FPGS technology is vital for quality assurance of the results produced, particularly following events that may impact on cervical precancer incidence rates. Failure to do so can result in potentially catastrophic screening incidents that are avoidable.

Computational design of prospective molecular targets for Burkholderia cepacia complex by molecular docking and dynamic simulation studies

The study aimed to screen prospective molecular targets of BCC and potential natural lead candidates as effective binders by computational modeling, molecular docking, and dynamic (MD) simulation studies. Based on the virulent functions, tRNA 5-methylaminomethyl-2-thiouridine biosynthesis bifunctional protein (mnmC) and pyrimidine/purine nucleoside phosphorylase (ppnP) were selected as the prospective molecular targets. In the absence of experimental data, the three-dimensional (3D) structures of these targets were computationally predicted. After a thorough literature survey and database search, the drug-likeness, and pharmacokinetic properties of 70 natural molecules were computationally predicted and the effectual binding of the best lead molecules against both the targets was predicted by molecular docking. The stabilities of the best-docked complexes were validated by MD simulation and the binding energy calculations were carried out by MM-GBSA approaches. The present study revealed that the hypothetical models of mnmC and ppnP showed stereochemical accuracy. The study also showed that among 70 natural compounds subjected to computational screening, Honokiol (3',5-Di(prop-2-en-1-yl) [1,1'-biphenyl]-2,4'-diol) present in Magnolia showed ideal drug-likeness, pharmacokinetic features and showed effectual binding with mnmC and ppnP (binding energies -7.3 kcal/mol and -6.6 kcal/mol, respectively). The MD simulation and GBSA calculation studies showed that the ligand-protein complexes stabilized throughout tMD simulation. The present study suggests that Honokiol can be used as a potential lead molecule against mnmC and ppnP targets of BCC and this study provides insight into further experimental validation for alternative lead development against drug resistant BCC.

Prospective parallel randomized trial of the MultiCyte™ ThinPrep(®) imaging system: the Scottish experience

BACKGROUND

Computer-assisted screening of cervical liquid-based cytology (LBC) preparations using the ThinPrep® Imaging System (TIS) has shown improved qualitative and quantitative gains. The use of Multicyte™ has not been described in a well-established national screening programme with a low incidence of high-grade dyskaryosis.

OBJECTIVES

To assess the impact of computer-assisted screening within the Scottish Cervical Screening Programme (SCSP).

METHODS

Two groups of three laboratories, each sharing a ThinPrep® Imager, screened 79 366 slides randomized to test and 90 551 to control arms by laboratory accession. Screeners were not blinded. Standard laboratory reporting profiles of the SCSP, sensitivity, specificity and false-negative rates of all grades of LBC abnormalities with respect to final cytology reports, predictive value for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) on histology; and screening rates were compared for both arms.

RESULTS

Inadequate and negative reporting rates were significantly lower and low-grade reporting rates significantly higher in the imager arm. Imager-assisted screening showed significantly better specificity than manual screening with respect to the final cytology result. There was no evidence of a significant difference in the detection of CIN2+ or CIN3 +. Positive, abnormal and total predictive values (high-grade, low-grade and all abnormal cytology found to be CIN2+, respectively) were similar in both arms. Productivity was significantly higher in the imager arm.

CONCLUSION

  Computer-assisted screening in a well established screening programme showed significantly improved productivity without loss of quality. These findings should inform future policy for cervical screening programmes.