Biomedical subjects

H Doornewaard

Publications and source records attributed to H Doornewaard.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Cost analysis of PAPNET-assisted vs. conventional Pap smear evaluation in primary screening of cervical smears.

OBJECTIVE: To assess the difference in costs between PAPNET-assisted and conventional microscopy of cervical smears when used as a primary screening tool. STUDY DESIGN: We performed time measurements of the initial screening of smears by four cytotechnologists in one laboratory. Time was measured in 816 conventionally screened smears and in 614 smears with PAPNET-assisted screening. Data were collected on the components of initial screening, clerical activities and other activities in the total work time of cytotechnologists in the routine situation and on resource requirements for both techniques. RESULTS: PAPNET saved an average of 22% on initial screening time per smear. Due to costs of processing and additional equipment, the costs of PAPNET-assisted screening were estimated to be $2.85 (and at least $1.79) higher per smear than conventional microscopy. The difference in costs is sensitive to the rate of time saving, the possibility of saving on quality control procedures and the component of the initial screening time in the total work time of cytotechnologists. CONCLUSION: Although PAPNET is time saving as compared with conventional microscopy, the associated reduction in personnel costs is outweighed by the costs of scanning the slides and additional equipment. This conclusion holds under a variety of assumptions. Using PAPNET instead of conventional microscopy as a primary screening tool will make cervical cancer screening less cost-effective unless the costs of PAPNET are considerably reduced and its sensitivity and/or specificity are considerably improved.

Cost-Benefit Analysis↗

PubMedDate not supplied

Reproducibility in double scanning of cervical smears with the PAPNET system.

OBJECTIVE: To determine the reproducibility of the PAPNET scanning station (Neuromedical Systems, Inc., Suffern, New York, U.S.A.) in selecting cells from a cervical smear. STUDY DESIGN: We compared the images of 196 smears that were scanned on two occasions by the PAPNET scanning station on two monitors simultaneously and compared the cellular contents and technical records provided by the scanning station. The sample consisted of 62 positive smears (mild dysplasia and more) and 134 negative smears. RESULTS: Although differences were found in the technical information provided by the scanning station (kappa = .65, 95% confidence interval [CI] = .51-0.79) and in the reported percentages of air bubbles (kappa = .60, 95% CI = .51-.68), the detection of abnormal cases was not affected. Furthermore, the agreement on microscopic review was excellent (kappa = .92, 95% CI = .88-.96). In nine cases that did not differ in tech code or percentage of air bubbles, however, differences were found in the cellular content of the tiles that would have led to different advice for additional microscopic review. This would have had important clinical consequences in two cases because a serious abnormality would have been missed. CONCLUSION: The consistency of the PAPNET scanning system is somewhat on the low side in providing technical information, although this did not affect the clinical outcome. In nine cases, for example, we found differences in the demonstration of cells in the tiles on the screen; two would have had clinical consequences. It is important to set goals for the performance of the machine and to incorporate them in the procedures to be used as standard practice. This is especially true when the scanning stations are going to be operated on site in the cytology laboratory.

Cervix Uteri↗

PubMedDate not supplied

Negative cervical smears before CIN 3/carcinoma. Reevaluation with the PAPNET Testing System.

OBJECTIVE: To test the effectiveness of the PAPNET testing system in identifying false negative smears, using archival cervical cytologic smears from women with histologically proven diagnoses of high grade lesions and carcinoma of the uterine cervix. STUDY DESIGN: Forty-six negative smears from women who developed a high grade cervical intraepithelial lesion (CIN 3) or carcinoma of the uterine cervix within three years were retrieved from the archives, plus 20 consecutive control smears for each case. The smears were analyzed with the PAPNET testing system, and the selected cells were reviewed by a cytotechnologist using a strict protocol. RESULTS: With the PAPNET testing system, 9 of 46 (20%) smears were positive. Seven were reclassified as low grade and two reclassified as high grade squamous intraepithelial lesion (SIL). One of the 31 initially positive smears in the control group of 920 smears was not recognized as such. In the control group of 889 negative smears, 14 newly identified positive cases (1.6%) were detected, all low grade SIL. CONCLUSION: The PAPNET testing system is a good tool for detecting false negative smears and, when used as an adjunct to conventional screening, can reduce the false negative rate.

Automation↗

PubMedDate not supplied

Cytoimmunologic monitoring as an adjunct in monitoring rejection after heart transplantation: results of a 6-year follow-up in heart transplant recipients.

The cytoimmunologic monitoring assay has been proposed as a useful noninvasive technique in the diagnosis of rejection and infection after heart transplantation. In this study, we have analyzed the diagnostic usefulness of cytoimmunologic monitoring in 73 patients after heart transplantation. For individual patients, the follow-up varied between 2 and 78 months. Data were related to histopathologic characteristics of the endomyocardial biopsy. Significantly different cytoimmunologic monitoring results were not observed between groups according to endomyocardial biopsy histopathologic evaluation. The diagnostic usefulness of cytoimmunologic monitoring depended on the cutoff value applied. With higher cutoff values, the sensitivity decreased and the specificity and predictive value increased. For the previously reported cutoff value of 5%, the sensitivity was 0.29, the specificity was 0.73, and the predictive value was 0.66. Values of sensitivity, specificity, and predictive value were similar when only the first acute rejection was taken into account, or when only data on the first 4 weeks and the first 6 months after transplantation were considered. In calculating the diagnostic usefulness of the sensitivity, specificity, and predictive values were observed. We concluded that cytoimmunologic monitoring has a limited value for diagnosing acute rejection after heart transplantation.

Acute Disease↗

PubMedDate not supplied

Cytotoxic T lymphocytes infiltrating the human cardiac allograft show a restriction in T-cell receptor V beta gene usage: a study on serial biopsy and blood specimens.

T lymphocytes were propagated in vitro from endomyocardial biopsy specimens that were obtained weekly from four patients during the first 2 to 3 months after heart transplantation. The culture was performed in the presence of recombinant interleukin-2 and interleukin-4, with or without mitogen, in which especially CD8+ donor-specific cytotoxic T cells expanded. These cells, presumably reflecting an in vivo activated population, could even be cultured from biopsy specimens without histopathologic signs of rejection. A preferential expression of T cell receptor V beta gene families was found in these T-cell lines. This finding is in contrast with the heterogenous expression in peripheral blood T cells of the same patient. The restriction in V beta gene family expression was substantiated in the evaluation of clones obtained from two cell lines. Among 17 donor-specific cytotoxic T-cell clones derived from one cell line, only four V beta gene families were expressed. All five clones from the other cell line used the V beta 8 family. Some clones expressing a distinct V beta gene family used the same V-D-J junction sequence, indicative of their origin from the same precursor. With the use of oligonucleotide probes complementary to clone-specific V-D-J junction sequences, four of five clones were detected not only in the parent T-cell line but also in T-cell lines derived from biopsy specimens with rejection reactions taken 1 week earlier and 2 weeks later and in blood cells taken before and 0.5, 3, and 6 months after transplantation; these clones were not detected in blood cells harvested 12 months after transplantation. This study showed a restricted usage of the V beta gene families by activated donor-specific cytotoxic T lymphocytes in the heart transplant.

Antigens, CD↗