Rapid Prescreening Research Articles

Rapid prescreen of cervical liquid‐based cytology preparations: Results of a study in an academic medical center

A rapid prescreening or rapid rescreening method for quality assurance in cervical cytology has been used in Europe and in Canada but has not been accepted in the United States. The rapid prescreen method was tested in a cytology laboratory that serves an academic medical center with a high-risk population for cervical cancer. For a period of 3 months, a tray of 20 sequentially numbered Surepath™ liquid-based preparations, randomly selected from the cervical cytology daily workload, were each prescreened in a random fashion for 1 minute. Experienced cytotechnologists performed the rapid prescreen. Results were recorded as negative, further review needed, or epithelial cell abnormality, category specified. The 20 cervical cytology preparations were then replaced in their same position in the daily workload for routine screening performed by another cytotechnologist. Final interpretation was by a cytopathologist as requested or required by Clinical Laboratory Improvement Amendments of 1988. The rapid prescreen data was tabulated and compared with data for a similar time period using the laboratory's normal quality assurance program. Seven hundred and twelve cases underwent rapid prescreen. Six hundred and forty-two were interpreted as negative. Twenty-six cases were interpreted as low-grade squamous intraepithelial lesion (LGSIL) or higher. Forty-four cases were classified as needing further review. For the 642 negative cases by rapid prescreening, routine screening reported 537 as negative and 105 as either abnormal or needed cytopathologist review. The error rate for the rapid prescreen is 50 of 712 (7.0%); for LGSIL and above 19 of 712 (2.6%). Of the 105 abnormal cases or those submitted for cytopathologist review, 31 were interpreted as atypical squamous cells of undermined significance (ASCUS), 41 cases as reactive/repair, 17 as LGSIL, 4 as unsatisfactory, 1 as atypical squamous cells, cannot rule out high-grade squamous intraepithelial lesion (ASC-H), 8 as the presence of endometrial cells in a women aged >40, 1 as malignant melanoma, and 2 as within normal limits with the presence of Actinomyces. The laboratory's routine quality assurance program selects cases, 10% of initially interpreted negative cases plus any gynecologic cytology on patients with a prior abnormal cervical cytology, or history of cervical epithelial cell abnormality. This quality assurance program averages 29% of cases, 4,045 of a total of 13,767, in 2008. Thirty-seven (0.9%) cases were detected in this rescreen (ASCUS, 16 cases; LGSIL, 13 cases; 1 high-grade squamous intraepithelial lesion; 4 ASC-H; and 3 atypical glandular cells of undetermined significance). Eliminating ASCUS cases, eight significant cases were detected, with an error rate of 0.2%. In this cytology laboratory, the rapid prescreen did not prove as reliable as routine quality assurance program for cervical cytology cases.

Rapid Pre-Screening Is More Sensitive in Liquid-Based Cytology than in Conventional Smears

Rapid pre-screening (RPS) is a useful tool to measure and improve performance in the cytology laboratory. Whether RPS is more or less effective in liquid-based cytology than in conventional smears is unknown. We compared the estimated sensitivity in a laboratory of 11 cytotechnologists which converted from conventional smears to SurePath™ (Becton Dickinson, Franklin Lakes, N.J., USA) liquid based cytology. In the 9 months prior to conversion, 23,286 smears were screened compared with 30,610 smears in the 12 months immediately after conversion. The estimated sensitivity of rapid pre-screening for 90 s improved significantly with liquid based cytology for all abnormalities (58.7 vs. 68.7%, p < 0.001), atypical squamous cells of undetermined significance + low-grade squamous intra-epithelial lesion (52.6 vs. 63.1%, p < 0.001), and high-grade squamous intra-epithelial alone (76.2 vs. 85%, p < 0.001). Histologic follow up for 156 cases identified by rapid pre-screening of SurePath slides showed 32 (21%) cases of CIN1 or greater and 18 cases (12%) with CIN3 or worse. We conclude that rapid pre-screening is significantly more sensitive in liquid-based cytology compared with conventional smears, and detects significant lesions that are missed by routine screening.

Individual estimated sensitivity and workload for manual screening of SurePath gynecologic cytology

Data correlating individual screening sensitivity in gynecologic cytology and workload is limited. We compared the estimated sensitivity of manual screening of SurePath slides with individual workload. Estimated sensitivity determined by rapid prescreening was correlated with total workload in a laboratory performing manual screening of SurePath preparations for a 1 year period. There were 12 CTs with a total daily workload ranging from 8-35 slides. The mean estimated sensitivity for SurePath was 97.0% (range 91-100%). The mean estimated sensitivity for the lowest half workload (8-23 slides/day) was significantly higher than that for the highest half workload (23-35 slides/day) (98.3 versus 95.7%, P ≤ 0.001). The highest workload that achieved 100% estimated sensitivity was 30 slides/day. For manual screening of SurePath slides, individual estimated sensitivity is correlated with workload even at relatively low daily workloads.

Rapid prescreening is as effective at reducing screening error as postscreening with the FocalPoint automated screening device

Both manual (rapid prescreening) and automated methods have been devised to reduce screening error compared with routine review of 10% of negative gynecologic cases. To date these two methods have not been compared. A total of 5,139 liquid-based (SurePath Pap Test, BD Diagnostics) cases were subjected to 100% rapid prescreening and routine manual screening. All cases diagnosed as negative on routine screening were placed on the FocalPoint (BD Diagnostics, Franklin Lakes, NJ) automated screening device. All cases that were negative on routine screening and abnormal on rapid prescreening or in the top 15% of cases by FocalPoint were rescreened and a final diagnosis obtained. Cases were blinded during rapid prescreening and routine manual screening. Abnormal was defined as any diagnosis of atypical squamous cells (ASC) or worse. A total of 427 (8%) of cases were abnormal on routine screening. The sensitivity of rapid prescreening was 44.6%. Rapid prescreening identified an additional 14 abnormal cases (13 ASC and 1 LSIL) and FocalPoint identified nine cases (eight ASC, one LSIL) that were not detected by routine screening. Three of these cases were detected by both methods. The sensitivity of routine screening was 93.1%. Rapid prescreening increased the overall sensitivity significantly (96.0%, P = 0.04); FocalPoint increased the sensitivity but this change was not significant (95.0%, P = 0.21). Estimated screening time was 30 seconds for rapid prescreening and 6 minutes for routine screening with the result that rapid prescreening required 2,570 minutes while review of the FocalPoint Slides required 2,694 minutes. The sensitivity of routine screening in the second half of the study (95.3%) was higher than that in the first half of the study (91.6%) but the difference was not significant (P = 0.11). Rapid prescreening is as effective as directed review using FocalPoint at reducing screening errors and requires no additional screening time. Continued use of these methods may improve the sensitivity of routine screening

Improved sensitivity over time with rapid prescreening in gynecologic cytology

Rapid prescreening (RPS) is a powerful tool to measure and improve performance in the cytology laboratory. Long-term use of RPS has been shown to result in improved sensitivity and precision in routine screening. The effect of long-term RPS on RPS itself is not known. We compared the sensitivity of 100% RPS of Surepath™ liquid-based cytology over a 4-year period in a laboratory of 11 cytotechnologists (CTs). In comparison with the first 2 years, RPS for the laboratory showed a significant increase in sensitivity for all abnormalities (72.2% vs. 67.3%, P < 0.001) and ASCUS + LSIL (68.5% vs. 62.1%, P < 0.001). For individual CTs s, the lowest sensitivity for all abnormalities increased from 59.0 to 63.2%, whereas, for HSIL, it increased from 71.4% to 75.0%. We conclude that long-term use of RPS leads to significant increase in the sensitivity of RPS.

The Use of [125I] Scintigraphic In Vivo Imaging in Melanoma-Bearing Mice for a Rapid Prescreening of Vectors to Melanoma Tissue

The use of radiolabeled molecules allows the study of in vivo biodistribution, target organs, and kinetic profile after systemic administration by 1) radioactive organ counting and 2) quantitative autoradiographic analysis of whole-body slices (WBA). However, these techniques are time- and animal consuming for several times studied. So, in vivo scintigraphic imaging should appear of interest for a first screening of compounds, as it is able to rapidly demonstrate tumoral uptake and kinetics by serial examinations in the same mice. In this study, the tumoral distribution and kinetics of six molecules considered as potential melanoma tracers radiolabeled with (125)I were analyzed by gamma-scintigraphy comparatively to the results obtained by WBA. Tumoral uptake has been quantified and expressed by: 1) tumor-to-background ratios and 2) standardized tumoral uptake (STU) in percent injected dose per gram, with tumor weight being extrapolated from the measurement of the two diameters. Results from STU analysis showed good agreement (correlation coefficient = 0.92) with those of WBA, and the same classification of compounds (on the basis of their melanoma affinity) was obtained, with two compounds (of six) being rejected. [(125)I] scintigraphic imaging appeared as a relevant, easy-going method for a first pharmacologic selection in mice.

Improvement in the routine screening performance of cytotechnologists over time

Documenting the performance of gynecologic screening in actual practice settings is difficult to achieve. In the current study, the screening performance of 11 individual cytotechnologists as well as that of the overall laboratory over 2 consecutive time periods was examined using the rapid prescreening (RPS) method. RPS was performed by all cytotechnologists in a single laboratory over 2 separate 8-month periods. The sensitivity of screening for individual and groups of cytotechnologists was examined. For purposes of comparison, cytotechnologists were divided into 2 groups: screeners with an overall routine sensitivity >or=95% and screeners with an overall sensitivity <95%. Atypical squamous cells (ASC) were used as a threshold, and routine screening sensitivity was found to vary from 68.3% to 96.8%. The overall sensitivity of the laboratory for RPS and routine screening was 43.6% and 88.4%, respectively. Over time, the overall laboratory sensitivity of routine screening improved from 85.3% to 91.3% (P = .01). During this same time frame, the sensitivity of the screeners with an overall sensitivity <95% improved from 79.3% to 91.2% (P < .001), whereas the sensitivity of screeners with an overall routine sensitivity >or=95% remained the same (96.1% to 96.4%; P = .6). In addition to improved overall performance of the laboratory by detecting and correcting errors, the results of the current study indicate that using RPS consistently over time might play a role leading to improved performance of cytotechnologists with an overall routine sensitivity <95% but not of cytotechnologists with an overall routine sensitivity >or=95%.

Rapid Prescreening as a Quality Assurance Measure in Cervical Cytology

To assess the diagnostic validity of rapid prescreening (RPS) as a quality control method in our laboratory.All consecutive routine conventional Pap smears (n = 2,521) underwent RPS before full screening. Thirty to 60 seconds were allowed to prescreen each slide. The threshold for pathologic smear was atypical squamous cells of undetermined significance (ASCUS) or more. Smear adequacy, infections and presence of endometrial cells, if observed, were not noted on the worksheet. All smears subsequently underwent routine full screening. Results of RPS and full screening were compared.Of a total of 2,521 smears, 294 were diagnosed as abnormal (ASCUS and more) after final diagnosis. Of those, 158 were also detected on RPS. The average sensitivity of RPS was 62.2%. Twenty-five cases were detected on RPS only, among them 15 ASCUS, 8 low-grade squamous intraepithelial lesions and 2 high-grade squamous intraepithelial lesions.RPS is an efficient quality control method. It reduces false negative rate, but in our case, it affects the work flow in our laboratory, and in case of its implementation to the routine praxis the daily workload of 50 smears per day should be lowered.

ASC/SIL Ratio for Cytotechnologists

The atypical squamous cell/squamous intraepithelial lesion (ASC/SIL) ratio has been used as a surrogate quality control tool for specificity and uncertainty for cytopathologists. Whether this ratio is useful for cytotechnologists is not known. During an 8-month period, the sensitivity of screening for 11 cytotechnologists was determined using rapid prescreening. The ASC/SIL ratio for each cytotechnologist was correlated with the screening accuracy for each. Screening sensitivity varied from 50.5% to 97.7%, and the ASC/SIL ratio varied from 0.87 to 4.49. The mean screening sensitivity for cytotechnologists with ASC/SIL ratios less than 1.5 was significantly less than that of cytotechnologists whose ASC/SIL ratio was more than 3.0 (67% vs 95%; P = .021). In the absence of more accurate quality control data, an ASC/SIL ratio less than 1.5 for a cytotechnologist may be a surrogate marker for inadequate screening sensitivity.

A Fast, Sensitive and Accurate High Resolution Melting (HRM) Technology-Based Assay to Screen for Common K-ras Mutations

Background: Increasing evidence points to a negative correlation between K-ras mutations and patient’s response to, or survival benefit after, treatment with EGFR-inhibitors. Therefore, rapid and reliable assays for mutational analysis of the K-ras gene are strongly needed.Methods: We designed a high resolution melting (HRM) technology-based approach followed by direct sequencing to determine K-ras exon 1 (codons 12/13) tumour genotype.Results: Reconstruction experiments demonstrated an analytical sensitivity of the K-ras exon 1 HRM assay following sequencing of 1.5–2.5% of mutated DNA in a background of wild-type DNA. Assay reproducibility and accuracy were 100%. Application of the HRM assay following sequencing onto genomic DNA isolated from formalin-fixed paraffin-embedded tumour specimens of non-small cell lung cancer (n=91) and colorectal cancer (n=7) patients revealed nucleotide substitutions at codons 12 or 13, including a homozygous mutation, in 33 (34%) and 5 (5%) cases, respectively. Comparison to conventional nested-PCR following cycle-sequencing showed an overall high agreement in genotype findings (kappa value of 0.96), with more mutations detected by the HRM assay following sequencing.Conclusion: HRM allows rapid, reliable and sensitive pre-screening of routine diagnostic specimens for subsequent genotyping of K-ras mutations, even if present at low abundance or homozygosity, and may considerably facilitate personalized therapy planning.

Rapid pre‐screening of cervical smears as a method of internal quality control in a cervical screening programme

To evaluate the performance of rapid pre-screening (RPS) as a method of internal quality control in the cytopathological examination of cervical smears for cervical cancer screening. The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis. Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS. RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists.

Comparison of the performance of rapid prescreening, 10% random review, and clinical risk criteria as methods of internal quality control in cervical cytopathology

Rapid prescreening (RPS) is an internal quality-control (IQC) method that is used both to reduce errors in the laboratory and to measure the sensitivity of routine screening (RS). Little direct comparison data are available comparing RPS with other more widely used IQC methods. The authors compared the performance of RPS, 10% random review of negative smears (R-10%), and directed rescreening of negative smears based on clinical risk criteria (RCRC) over 1 year in a community clinic setting. In total, 6,135 smears were evaluated. The sensitivity of RS alone was 71.3%. RPS detected significantly more (132 cases) false-negative (FN) cases than either R-10% (7 cases) or RCRC (32 cases). RPS significantly improved the overall sensitivity of the laboratory (71.3-92.2%; P = .001); neither R-10% nor RCRC significantly changed the sensitivity of RS. RPS was not as specific as the other methods, although nearly 68% of all abnormalities detected by RPS were verified as real. RPS of 100% of smears required the same amount of time as RCRC but required twice as much time as R-10%. The current results demonstrated that RPS is a much more effective IQC method than either R-10% or RCRC. RPS detects significantly more errors and can improve the overall sensitivity of a laboratory with either a modest increase or no increase in overall time spent on IQC. R-10% is an insensitive IQC method, and neither R-10% nor RCRC can significantly improve the overall sensitivity of a laboratory.

Measuring the significance of workload on performance of cytotechnologists in gynecologic cytology

Workload is extensively regulated and often used as a measure of quality in gynecologic cytology. Whether workload correlates with the sensitivity of screening in gynecologic cytology is not known. The sensitivity of gynecologic cytology screening was measured over an 8-month period using the result of full screening coupled with the results of rapid prescreening. Sensitivity results were then correlated with daily workload volumes and the experience level of individual cytotechnologists. Rapid prescreening had an average sensitivity of 41.9% for atypical squamous cells of undetermined significance (ASCUS) and above. Full screening had a corrected sensitivity of 82.2% for ASCUS and above. Rapid prescreening increased the sensitivity of the laboratory to 89.9%. The sensitivity of full screening was significantly different between cytotechnologists (79.2% vs 99%, P < .001), but was not correlated with years of experience, sensitivity of rapid prescreening, or workload (all P > .05). When sensitivity and workload were examined on a monthly basis, there was no significant difference between sensitivity either as a group or individually at the highest and lowest workloads (P > .40 for all). Screeners sensitivity in gynecologic cytology appears to be unrelated to the experience level of individual cytotechnologists or to their workload at the levels examined.

Estimation of Standard Heats of Formation of Fullerenes Using Pentagon-Centered Motifs

Standard heats of formation (Δ ) calculated at B3LYP/6-31G(d) for 114 isolated pentagon rule fullerenes were reproduced within 4.2 kcal/mol on the basis of 24 pentagon-centered motifs. With the use of a C30-capped (5,5) single-walled carbon nanotube as test molecule, it is found that (i) both hexagon- and pentagon-centered motifs can be employed to estimate the Δ of fullerenes, while the latter gives better results for large fullerenes; and (ii) with the consideration of nonplanar strain energy, the estimated results of Δ can be further improved. The estimation scheme of pentagon-centered motifs can serve as a rapid prescreening tool for viable isomers of large fullerenes and is expected to be equally valuable for carbon nanotubes.

Detection of novel NF1 mutations and rapid mutation prescreening with Pyrosequencing

Neurofibromatosis type 1 (NF1) is caused by mutations in the neurofibromin (NF1) gene. Mutation analysis of NF1 is complicated by its large size, the lack of mutation hotspots, pseudogenes and frequent de novo mutations. Additionally, the search for NF1 mutations on the mRNA level is often hampered by nonsense-mediated mRNA decay (NMD) of the mutant allele. In this study we searched for mutations in a cohort of 38 patients and investigated the relationship between mutation type and allele-specific transcription from the wild-type versus mutant alleles. Quantification of relative mRNA transcript numbers was done by Pyrosequencing, a novel real-time sequencing method whose signals can be quantified very accurately. We identified 21 novel mutations comprising various mutation types. Pyrosequencing detected a definite relationship between allelic NF1 transcript imbalance due to NMD and mutation type in 24 of 29 patients who all carried frame-shift or nonsense mutations. NMD was absent in 5 patients with missense and silent mutations, as well as in 4 patients with splice-site mutations that did not disrupt the reading frame. Pyrosequencing was capable of detecting NMD even when the effects were only moderate. Diagnostic laboratories could thus exploit this effect for rapid prescreening for NF1 mutations as more than 60% of the mutations in this gene disrupt the reading frame and are prone to NMD.

Controle da qualidade em colpocitologia: visão rápida com campo marcado

INTRODUCTION: The Pathology and Forensic Medicine Department of the Faculdade de Medicina de Sao Jose do Rio Preto, SP had decided to develop a Quality Control System following the NBR ISO 9001: 2000 guidelines. Some procedures were adopted to verify technical reliability for the exams performed, where quality is defined as the clients' judgement, i.e., the solution for the clients' requests and expectations. In this study we have focused on the quality of the cervical cytology performed in the Department. Although the development of cervical lesions through cervical carcinoma takes place slowly, the treatment will have a better chance of success in case of an early diagnosis. Considering all the possible diagnostic mistakes, the false-negative exam is the most dangerous, as it delays the beginning of the treatment. OBJECTIVE: To test three different methods looking for the one with the smaller number of false-negative results. MATERIAL AND METHODS: For the same team of technicians, and with the same diagnostic criteria the three different techniques were tested. Methodology 1 (M1): in accordance to the Brazilian Ministry of National Health, with a random review of 10% of the false-negative results, in the 3,500 cytologies; Methodology 2 (M2): rapid review (RR), as suggested in literature, consists of a rapid review of 100% of the smears, after their routine evaluation, and was done in 7,373 cytologies; Methodology 3 (M3): rapid prescreening (RP) with marked field, was proposed by the researcher and consists of a rapid screening of all cases, pointing out a field were there are abnormal cells, and after that the normal screening, in 8,096 cytologies. RESULTS: The three techniques tested showed the following false-negative rates: M1: 2.4%; M2: 1.7% and M3: 1.2 %. CONCLUSION: The M3 was the best methodology, presenting less false-negative diagnosis.

Correlation of cytotechnologists' parameters with their performance in rapid prescreening of papanicolaou smears

Efficient quality control is essential to ensure high sensitivity of Papanicolaou (Pap) smears. For this purpose, rescreening of 10% random negative smears is increasingly felt to be ineffective. Rapid rescreening (RR) of all negative Pap smears is more practical and has received widespread acceptance, especially in Europe, although its sensitivity is difficult to monitor and its retrospective nature may influence the vigilance of the screeners. The method of rapid prescreening (RPS) overcomes these drawbacks because rapid review of Pap smears precedes full screening. All routine conventional Pap smears (n = 8364) over 2 months underwent RPS by 12 cytotechnologists, followed by full screening. Data were analyzed to determine correlation between the RPS sensitivity of individual cytotechnologists and both their sensitivity in full screening and their years of experience as cytotechnologists. There was a striking variability in sensitivity (15.4%-72.7%) among the 12 screeners with an atypical squamous cells of undetermined significance (ASCUS) threshold. There was no correlation between RPS sensitivity of individual cytotechnologists with either their sensitivity in full screening or their years of experience as cytotechnologists. The skills required of a cytotechnologist for achieving a high sensitivity in RPS are apparently different from those of full screening and are independent of the sensitivity of the screeners at full screening or of the years of experience as cytotechnologists.

Rapid prescreening of Papanicolaou smears

I thoroughly enjoyed reading the article by Djemli et al.1 Their study stands on its own, but several points deserve repeated emphasis. First, when the corrected error rate is used as detailed in the discussion section, the results can be compared with those of other studies. This is the value of using the corrected error rate, because one cannot compare the uncorrected values. For example, if one uses what to my knowledge is the only published sensitivity of 10% review of negative smears,2 then 10% review of negative smears in the same study would have been expected to only detect 0.4 rather than 17 missed cases. A 4000% improvement in error detection is quite impressive. Second, to my knowledge, the reported error rate of 12% is the best error rate in actual clinical practice published to date. When compared with Canada, the best published error rate in the U.S. without computer assistance is only 20%.3 It is intriguing that the workload in this laboratory appears different from those in many U.S. laboratories, and studies such as this may actually be able to measure the value of workload in the future. However, for now, the currently available published data clearly demonstrate that the best place to have your Papanicolaou smear read is not in the U.S. However, my real goal is to encourage other laboratories to try rapid prescreening. A thorough review of 10% of all negative slides sounds like a useful quality assurance technique, but the facts show otherwise. Rapid prescreening appears to be a technique that is too slipshod to actually work, but the facts demonstrate otherwise.

Rapid prescreening of papanicolaou smears

Efficient quality control (QC) is essential to ensure high sensitivity of Papanicolaou (Pap) smears. For this purpose, rescreening of 10% random negative smears is ineffective. Rapid rescreening (RR) of all negative Pap smears is more practical and has received widespread acceptance, especially in Europe, although its sensitivity is difficult to monitor and its retrospective nature may influence the vigilance of the screeners. The method of rapid prescreening (RPS) overcomes these drawbacks because rapid review of Pap smears occurs before routine full screening. All routine conventional Pap smears over 2 months underwent RPS by 12 cytotechnologists. Approximately 30 seconds were allowed to prescreen each slide. The presence of abnormal cells (atypical squamous cells of undetermined significance [ASCUS] or above), infection or endometrial cells detected on RPS was documented. All slides subsequently underwent routine full screening. Results of both screening methods were compared. Of a total of 8364 Pap smears, 310 (3.7%) cases were categorized as abnormal after final diagnosis. Of those, 135 were also detected on RPS (sensitivity of 43.5%). Seventeen abnormal cases were detected only on RPS: these consisted of 13 ASCUS cases, 3 low-grade squamous intraepithelial lesions, and 1 high-grade squamous intraepithelial lesion. The sensitivity of RPS for infections and endometrial cells was 51.6% and 28.3%, respectively. Implementation of RPS did not significantly impact the work flow in our laboratory. RPS is an efficient and practical QC tool. It is a reliable method with which to monitor sensitivity and reduce the false-negative rate, and because it is done before finalizing the case, it allows for timely corrections to the diagnosis and avoids the need to amend reports.

Non-destructive prediction of chemical composition in sunflower seeds by near infrared spectroscopy

Near infrared reflectance spectroscopy (NIRS) was explored as a technique to predict moisture (M), oil and crude protein (CP) content on intact sunflower seeds ( Helianthus annuus L.). Three hundred samples were scanned intact in a monochromator instrument NIRS 6500 (NIRSystems, Silver Spring, MD, USA). Calibration equations were developed using modified partial least square regression (MPLS) with internal cross validation. Samples were split in two sets, one set used as calibration ( n=250) where the remaining samples ( n=50) were used as validation set. Two mathematical treatments (first and second derivative), none (log 1/ R) and standard normal variate and detrend (SNVD) as scatter corrections were explored. The coefficient of determination in calibration ( R cal 2) and the standard error in cross validation (SECV) were 0.95 (SECV: 3.3) for M; 0.96 (SECV: 13.1) for CP and 0.90 (SECV: 22.3) for oil in g kg −1 on a dry weight basis (second derivative, 400–2500 nm). Prediction models accounted for less than 65, 70 and 72% of the total variation for oil, M and CP, respectively. However, it was concluded that NIRS is a suitable technique to be used as a tool for rapid pre-screening of quality characteristics on breeding programs.