Comparison of TriPath thin-layer technology with conventional methods on nongynecologic specimens

OBJECTIVE: To evaluate the use of the TriPath PREP (previously called AutoCyte) TriPath Inc., Burlington, North Carolina, U.S.A.) in nongynecologic cytologic material by performing side-by-side comparison of conventional preparations with TriPath-prepared slides. STUDY DESIGN: An initial study of 613 cases (set A) was conducted to compare the TriPath PREP system with conventional methods for the evaluation of nongynecologic specimens, including urine, body cavity effusions, cerebrospinal fluid, pulmonary and gastrointestinal specimens. Paired cases were evaluated for cellularity, staining quality, preservation and representation of diagnostic material. Subsequent changes in the automated technique warranted reevaluation of the TriPath method. The follow-up study of 259 cases (set B) was conducted with the same design as set A. Results of evaluated parameters were analyzed using the chi 2 test. RESULTS: Results of the two sets were strikingly different. Prior to technical changes made by the laboratory, the TriPath method was significantly inferior. In the second set, the preferred material was most commonly the TriPath-prepared material. In particular, the majority of urine samples were prepared better by the automated, thin-layer system. CONCLUSION: The TriPath PREP system offers a reliable preparation of urine and has potential for other nongynecologic specimens, provided that careful attention is paid to technical details and some adjustments are made to account for specimen variability.     

Evaluation of thin-layer methods in urine cytology

Conventional cytospin smears prepared from urinary tract specimens were compared with two new thin layer techniques, i.e. ThinPrep and AutoCyte PREP. Cellularity, cell preservation, background features, detection rate, screening time and ease of preparation were evaluated. Thin-layer techniques when applied to urine cytology were found to improve cell yield and cell preservation, and reduce background artefact. The reporting rate for abnormal urothelial cells was comparable to conventional cytospin smears, as was screening time. Laboratory staff found the methodologies to be practicable and easily incorporated into a large routine diagnostic service. We conclude that a one-slide thin-layer urine preparation is comparable to four cytospin slides in the detection of urothelial abnormalities, and that both ThinPrep and AutoCyte PREP have comparable features.     

Processing liquid-based gynecologic specimens: comparison of the available techniques.

OBJECTIVE: To develop a cytopreparation protocol suitable for satisfactory processing by the AutoCyte PREP System with the gynecologic specimens collected in PreservCyt fluid for the ThinPrep machine. STUDY DESIGN: The residue of a number of gynecologic specimens collected in PreservCyt and processed by ThinPrep were processed by AutoCyte PREP. Some modifications were made in the cytopreparatory protocol in order to obtain satisfactory specimens. RESULTS: The ThinPrep and AutoCyte PREP specimens were examined independently. The results were comparable, with a high degree of concordance between the two techniques. CONCLUSION: Gynecologic specimens collected in PreservCyt and following the ThinPrep specimen collection protocol can be processed using the AutoCyte PREP System. Minor protocol modifications provided comparable diagnostic material. Additional studies are needed to explore the feasibility of this approach and fulfill the various U.S. regulatory agency requirements for the liquid-based Pap test.     

Evaluation of the AutoCyte SCREEN system in a clinical cytopathology laboratory

OBJECTIVE: To compare the AutoCyte SCREEN (AutoCyte, Burlington, North Carolina, U.S.A.) system with manual screening by experienced cytotechnologists using thin-layer preparations that had been previously extensively studied and their cytologic abnormalities well defined. STUDY DESIGN: AutoCyte PREP (AutoCyte) samples prepared for a previous split-sample study comparing thin-layer preparations to conventional smears were used. These 1,992 AutoCyte PREP samples were in a cohort the abnormal findings of which had been confirmed via independent review by two sets of pathologists. For the current study, these samples were remasked and evaluated by the AutoCyte SCREEN system in a clinical laboratory. The instrument scanned each slide and selected six overview fields and 120 single objects for storage and display. The computer classified each slide in one of the following categories: abnormal, uncertain, normal or unsatisfactory. Independently for each case, a cytotechnologist evaluated the six fields and 120 objects selected by the instrument as abnormal, normal or unsatisfactory. For those cases classified as uncertain by AutoCyte, the technologist then reexamined the cellular displays and entered a consensus classification. These results were then compared to those of an independent review by cytotechnologists of the identical set of slides using routine manual screening. RESULTS: The AutoCyte SCREEN selected 35% of slides for manual review. Technologist and computer rendered equivalent classifications in 79%. Of the total slides screened by the AutoCyte SCREEN, 57% were classified as "uncertain," and 88% of these were subsequently classified as normal by consensus. Using the well-defined abnormal values of the cellular sample as a basis for calculation, the AutoCyte SCREEN-assisted practice had a diagnostic sensitivity of 85% and diagnostic specificity of 97.6%. Comparable values for manual screening of the identical cellular sample were a diagnostic sensitivity of 80% and specificity of 97.4%. CONCLUSION: The AutoCyte SCREEN achieves comparable or greater sensitivity in detecting cervical abnormalities in comparison with manual screening. When combined with the substantial advantage of thin-layer preparations over conventional smears, the AutoCyte SCREEN provides a screening system of superior sensitivity over conventionally prepared and examined cervical smears.     

Intraocular large B-cell lymphoma. A case report

BACKGROUND: Large cell lymphoma involving the vitreous humor is uncommon, and its diagnosis in the absence of central nervous system disease can be difficult. The major diagnostic difficulties with vitreous washings in the absence of ancillary studies are in the distinction of inflammatory lymphoid infiltrate from intraocular lymphoma or diagnosing lymphoma when only very few neoplastic cells are present. CASE: A 75-year-old, white male sought medical attention for bilateral blurred vision and decreased visual acuity of recent onset. A clinical diagnosis of bilateral uveitis to rule out primary intraocular lymphoma or an infectious process was made, and a right vitrectomy was performed. An unequivocal diagnosis of lymphoma could not be made due to the paucity of neoplastic cells on that specimen. Two months later smears from the Cytospin (Thermo Shandon, Pittsburgh, Pennsylvania, U.S.A.) prepared on the specimen from a left vitrectomy showed a greater number of large, pleomorphic cells. In addition, immunocytochemical staining confirmed the B-cell lineage of the neoplastic cells. Immunoglobulin gene rearrangement analysis performed by the polymerase chain reaction method on the frozen cell pellet from the left vitrectomy demonstrated the presence of a monoclonal B-cell population, confirming the diagnosis of large B-cell lymphoma. CONCLUSION: Vitreous cytology in conjunction with ancillary studies is a sensitive procedure in the diagnosis of intraocular lymphoma.     

Liquid-based cytology in breast fine needle aspiration. Comparison with the conventional smear

OBJECTIVE: To compare the various cytologic features on AutoCyte Prep (ACP) (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) and conventional preparation (CP) specimens from breast fine needle aspiration cytology material with a semi-quantitative scoring system. STUDY DESIGN: A total of 100 randomized cases were studied. In each case, 2 passes were performed. One pass was used for CPs (Giemsa and Papanicolaou stain). The other pass produced material for the ACP technique and Papanicolaou stain. Both the conventional and liquid-based preparations were studied independently by two observers and compared for cellularity, obscuring and/or informing background, representative diagnostic material, preservation of cytomorphologic features, presence of monolayer cells and architectural arrangement. RESULTS: Comparing the two preparations, the results were as follows: (1) ACP was superior to CP in 2 features, lack of obscuring background and presence of monolayer arrangement with preservation of cell architecture; (2) ACP was inferior to CP in 1 feature, lack of informing background; and (3) ACP was equal, with small deviations, to CP in the rest of the features evaluated: cellularity, representative diagnostic material, preservation of cell morphology and architectural arrangement. CONCLUSION: The new technology of liquid-based cytology in breast FNA showed a good correlation with CP plus the advantages of: (1) easier and less time consuming evaluation of cell morphology (clear background, no overlapping, smaller area to screen); (2) reproducibility, a factor of great importance to quality control; and (3) possibility of adjunctive investigations (immunocytology, flow cytometry) on the same material.     

Use of automated primary screening on liquid-based, thin-layer preparations

OBJECTIVE: To evaluate the accuracy of the AutoPap System (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) (TriPath) in screening AutoCyte PREP liquid-based, thin-layer preparations by comparing the final cytologic diagnoses with instrument slide classification results. STUDY DESIGN: A total of 9,665 AutoCyte PREP thin-layer slides were first independently screened to establish a final cytologic diagnosis (reference diagnosis). The slides were then processed on the AutoPap System. Each slide successfully processed was reported into result categories. The generated report gave a ranking score for each slide designated for "review." Slides designated "no further review" (NFR) were also listed in the report. The reported results were then compared to the reference cytologic diagnoses. RESULTS: Of 9,665 slides initially submitted to the AutoPap, 8,688 (90.8%) were qualified for scanning, and 884 (9.2%) were definitely classified as process review or rerun and excluded from the study. Of high grade squamous intraepithelial lesions and greater (HSIL+), 85.2% were ranked in the first rank, 12.7% in the second, one (2.1%) in the third, none in the fourth and fifth and none in the NFR category. Of low grade squamous intraepithelial lesions, 47.4% were ranked in the first rank, 20.8% in the second, 10.6% in the third, 10.1% in the fourth, 5.3% in the fifth and 5.8% in NFR. Of atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance, 53.6% were ranked in the first rank, 22.5% in the second, 12.4% in the third, 5.4% in the fourth, 3.8% in the fifth and 2.3% in NFR. Considering a cutoff value at < or = 3rd rank, 84% of cervical abnormalities (RR 6.52, 95% CI 4.96-8.66) and 100% of HSIL+ were identified. CONCLUSION: The AutoPap demonstrates a high capability for detecting cervical abnormalities on AutoCyte PREP thin-layer slides. HSIL+ was associated with the highest instrument scores.     

Comparison of ThinPrep and conventional preparations on fine needle aspiration cytology material

OBJECTIVE: To compare the various cytologic features on ThinPrep 2000 (TP) (Cytyc Corporation, Marlborough, Massachusetts, U.S.A.) and conventional preparation (CP) specimens from fine needle aspiration cytology (FNAC) material by a semiquantitative scoring system. STUDY DESIGN: In this prospective study a total of 71 consecutive cases were included. In each case, two passes were performed. The first pass was used for conventional preparations, with direct smears made and fixed immediately in 95% alcohol for Papanicolaou stain. For TP preparation a second pass produced material for processing in the ThinPrep 2000. The TP and CP slides were studied independently by two observers and representative slides of CP and TP compared for cellularity, background blood and necrotic cell debris, cell architecture, informative background, presence of monolayer cells, and nuclear and cytoplasmic details by a semiquantitative scoring system. Statistical analysis was performed by Wilcoxon's signed rank test on an SPSS program (Chicago, Illinois, U.S.A.). RESULTS: TP preparations contained adequate diagnostic cells in all cases and were tangibly superior to CP preparations concerning monolayer cells, absence of blood and necrosis, and preservation of nuclear and cytoplasmic detail (statistically significant, Wilcoxon's signed rank test, P < .000). CONCLUSION: TP preparations are superior to conventional preparations with regard to clear background, monolayer cell preparation and cell preservation. It is easier and less time consuming to screen and interpret TP preparations because the cells are limited to smaller areas on clear backgrounds, with excellent cellular preservation. However, TP preparations are more expensive than CP and require some experience for interpretation.     

Analysis of urine cytology tests in 120 paired cases

OBJECTIVE: To evaluate the smear quality and diagnostic accuracy of ThinPrep processing in comparison to conventional Cytospin technique for urinary cytology. STUDY DESIGN: ThinPrep and Cytospin techniques were retrospectively evaluated by 2 observers in a double-blinded, randomized fashion. Each quality parameter was scored using a semi-quantitative score of 1-3. Diagnostic accuracy indices were calculated with biopsy histology as the gold standard. RESULTS: Quality of cellular distribution and cell preservation were better with Cytospin preparations, whereas ThinPrep smears were superior in terms of stain distribution and cleaner slide background. However, the only significant differences observed were in cellular distribution and a clean background (p < 0.05). Sensitivity and positive and negative predictive values were higher with Cytospin than the ThinPrep technique (90.0%, 94.7% and 71.4% vs. 80.0%, 94.1% and 55.6%, respectively). Conversely, the specificity of both techniques was comparable. CONCLUSION: The Cytospin smears were of better quality than those prepared by the ThinPrep technique. Although both techniques resulted in similar diagnostic accuracies in negative cases, the ThinPrep preparations were not found to be superior to Cytospin smears in diagnosing positive urinary cytology.     

Bladder cancer diagnosis by computer image analysis of cells in the sediment of voided urine using a video scanning system

A video-based computerized semiautomated image analysis system was applied to the diagnostic evaluation of 119 sediments of voided urine: 103 from patients with a broad variety of neoplastic and nonneoplastic disorders of the lower urinary tract and 16 normal controls. Each specimen was presented to the machine as a single cytocentrifuge preparation, preserved in 2% Carbowax in 50% ethanol and stained-by the Papanicolaou method. Five hundred sequential "objects" were scanned within an area of 9 sq mm on each slide. "Objects" of no diagnostic value, such as dirt, debris, inflammatory cells, cell clusters, poorly preserved cells, etc., were eliminated from the final diagnostic analysis by a computer-based hierarchic triage system. The final specimen classifier was based on the cell images identified by the computer as well-preserved normal (NEG), atypical (ATY I), suspicious (ATY II) and malignant (POS) cells. For specimen classification by computer, the four categories of "abnormal," "inadequate," "acellular" and "negative" were defined. For high-grade tumors, the performance of the specimen classifier was generally comparable to the visual diagnosis. The specimen classifier unexpectedly identified twice as many low-grade papillary urothelial tumors as abnormal than did the visual analysis. Several false "alarms" were recorded by computer in patients with benign prostatic hypertrophy and prostatic carcinoma, some of whom had atypical urothelium. One of the 16 negative controls was misdiagnosed by the computer as abnormal. The possibility that the video system recognizes nuclear abnormalities not perceived by the human eye is being investigated further. The details of the computer analysis are reported, and the value of the system is discussed. The system appears to be promising as a future laboratory instrument, although it requires further extensive testing.     

Planimetry of bronchoalveolar macrophages. Importance of preparation and staining techniques.

Bronchoalveolar lavage seems a well-established, valuable research tool in the study of alveolar macrophages. The influence of fixation, cytocentrifugation and staining procedures on the cellular and nuclear size has been investigated by planimetry. As a reference, mean profile areas of 109 and 39 microns 2 for cell and nucleus, respectively, were measured for alveolar macrophages suspended in the hemocytometer. For comparison, stained Cytospin preparations were measured. Unfixed cells were compressed during cytocentrifugation. The cellular profile areas for Cytospin preparations increased about 15% and 70% after May-Grünwald-Giemsa and Feulgen staining, respectively. The nuclear area was approximately 25% larger for both staining procedures as compared to the hemocytometer values. When the cells had been fixed prior to cytocentrifugation, these differences were less conspicuous. No significant differences were observed after May-Grünwald-Giemsa staining, showing a cellular area of 114 microns 2 and a nuclear area of 45 microns 2. Depending on the staining procedure, low nucleus:cell ratios (31%) were observed after Feulgen staining, while higher values (about 43%) were measured after May-Grünwald-Giemsa staining, regardless of which fixation or centrifugation procedure had been followed. In conclusion, these findings indicate that fixation should be carried out in order to prevent cell changes resulting from cytocentrifugation. Moreover, different staining procedures considerably influence the measurement of cellular and nuclear profile areas and the determination of nucleus:cell ratios.     

Comparison of manual and automated methods of liquid-based cytology. A morphologic study

OBJECTIVE: To evaluate the morphologic characteristics of gynecologic samples prepared by 3 different methods of liquid-based cytology. STUDY DESIGN: Cytologic samples from representative cases of each diagnostic category of squamous epithelial lesion, prepared by automated and manual liquid-based systems, were analyzed by 3 laboratories in the United States, Portugal and Brazil. The systems included: ThinPrep (automated, U.S. Food and Drug Administration approved; Cytyc Corp., Boxborough, Massachusetts, U.S.A.), Autocyte PREP (South American system, manual; TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) and DNACITOLIQ (manual; Digene Brazil, S?o Paulo, Brazil). A panel of 16 morphologic parameters was evaluated: cellularity, clean background, uniform distribution, artifacts, cellular overlapping, architectural and cytoplasmic distortion, cytoplasmic vacuolization, cellular elongation, imprecise cytoplasmic borders, folded cytoplasmic borders, nuclear hyperchromasia, coarse chromatin, prominent nucleolus, irregular nuclear borders, atypical mitosis and inflammatory infiltrate. Negative, atypical squamous cells of undetermined significance, low grade squamous intraepithelial lesion (LSIL) and high grade squamous intraepithelial lesion (HSIL) cases were included. Cases without biopsies were confirmed by consensus. RESULTS: Cellularity was adequate in all samples. Clean background was observed in the vast majority of samples with all liquid-based systems. Uniform distribution was frequently found in ThinPrep and Autocyte PREP samples but not in DNACITOLIQ. Artifacts were not present in DNACITOLIQ samples, rare in ThinPrep and observed in 8 (34.7%) Autocyte PREP. Cellular overlapping was observed in all 3 system samples: 11 (31.42%) cases in ThinPrep, 16 (69.56%) in Autocyte PREP and 17 (68%) in DNACITOLIQ System. Architectural and cytoplasmic distortion were present in 3 cases of HSIL (13%) and cytoplasmic vacuolization in 2 cases of LSIL and 1 HSIL of Autocyte PREP. Cellular elongation was found in 13 (56.5%) Autocyte PREP and in 5 (20%) DNACITOLIQ samples. Inflammatory infiltrate was found in all 3 system samples but with more frequency in the Autocyte PREP (69.56%) and DNACITOLIQ System (72%). CONCLUSION: This study clearly indicated that in spite of the different methodologies, the 3 methods adequately preserved cellular structure for morphologic evaluation. The choice of method will depend on price, availability and procedures involved.     

Diagnostic value of CA 15-3 antibody in detecting metastatic adenocarcinoma

OBJECTIVE: To determine the diagnostic value of CA 15-3 in detecting metastatic adenocarcinoma in body fluids using PreservCyt solution (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) as collection fluid. STUDY DESIGN: Cytospin slides prepared from 72 cases with unequivocally benign or malignant diagnosis were studied. Of the cases studied, 34 were breast carcinomas, and 17 were benign pleural effusions. Slides were stained for CA 15-3 by using the avidin-biotin complex method. Cases were evaluated for the presence of membranous or cytoplasmic staining. The percentage of cells exhibiting strong staining was estimated for both breast carcinoma and all adenocarcinomas as a group. These results were compared with CA 15-3 staining exhibited by benign mesothelium. RESULTS: Ninety-one percent of the breast cancer cases studied showed a positive reaction with CA 15-3, while 6% of the benign mesothelium cases were positive (p < 0.01). The sensitivity of CA 15-3 was 91 % for breast carcinoma and 80% for all adenocarcinomas. Specificity was 94% for breast carcinoma and for all adenocarcinoma. CONCLUSION: CA 15-3 is a sensitive and specific marker for diagnosing adenocarcinoma in cytologic specimens using PreservCyt solution as collection fluid.     

The value of multiple preparations in the diagnosis of malignant pleural effusions. A cost-benefit analysis

A cost-benefit analysis of five techniques employed in processing 108 malignant pleural effusions for cytopathologic examination was performed. Ethanol-fixed, Papanicolaou-stained smears were positive in 68% of the effusions, air-dried Diff-Quik-stained smears in 66%, Cytospins in 83%, cell blocks in 85% and Millipore filters in 85%. Examination of one air-dried smear and one ethanol-fixed smear yielded a diagnostic sensitivity of 82%. Using a combination of two smears and one of three concentrating techniques (Cytospin, cell block or MIllipore filter) would have provided a diagnosis in over 90% of the effusions. The use of four or more preparations provided more sensitivity than did three preparations and decreased the likelihood that a malignant diagnosis would be based on the findings in only one preparation. The costs related to disposable materials and the College of American Pathologists (CAP) work load estimates for specimen preparation, staining and screening were compared. These data may be useful in developing optimal protocols for pleural effusion preparation in laboratories with specific work load requirements and limited resources.     

Comparison of two methods of storing breast fine needle aspirates (FNAs) using oestrogen receptor immunocytochemical assay as a method of evaluating the storage methods

Two methods of storing fine needle aspirates were compared in 14 patients with breast cancer. the methods of storage were: (1) as a Cytospin slide prepared immediately from the aspirated material and stored at −80°C; (2) as a suspension of cells in tissue culture medium, stored at −80°C. the effect of storage on the cells was assessed by means of an oestrogen receptor immunocytochemical assay (ER-ICA). an ER positivity of 100% was obtained by ER-ICA staining of cells after storage method 1, whilst all of the specimens stored by method 2 were ER-negative. the data demonstrate that cells stored in tissue culture medium at −80°C are not suitable for ER measurement. the storage method of choice for specimens intended for ERICA is as a Cytospin slide. the ER status of cells deposited on Cytospin slides prepared immediately and stored at −80°C for 2 years could be demonstrated despite the delay in processing the specimen.     

Thin-layer preparations of dithiothreitol-treated bronchial washing specimens

OBJECTIVE: To evaluate the combined effect of dithiothreitol (DTT) treatment and ThinPrep (TP) (Cytyc Corp, Boxborough, Massachusetts, U.S.A.) processing on bronchial washing specimens. STUDY DESIGN: A total of 431 bronchial washing specimens were initially treated with 0.05% DTT in a 30% methanol solution. After centrifugation, 1 TP slide and 2-4 conventional cytospin or smear preparations (CPs) were prepared. The reports of both preparations were compared in all cases. All 48 abnormal cases and 52 consecutive negative cases were also compared for cellular composition, distribution of the cells, ease of interpretation and overall preparation quality. Screening time was recorded for 20 of the cases. RESULTS: The diagnostic accuracy of one TP slide appeared comparable to that of 2-4 CPs. The TP slide was assessed to be equal or superior in overall quality to CP in 85% of 100 cases of paired specimens. The cleaner background and smaller cellular area of TP slides significantly reduced the screening time. Mucolysis and specimen homogenization were not always optimal, occasionally resulting in uneven subsampling and poorly cellular TPs. However, in general, TP slides were considered superior to CPs in overall quality. CONCLUSION: Improvement in specimen quality and reduced screening time have to be balanced against the high cost of consumables with the TP technique.     

Enhancing recovery of endocervical component on gynecologic cytology specimens processed by thin-layer technology

OBJECTIVE: To address the causes and report the corrective measures required for resolving the initial problem of high rates of cervical vaginal cytology specimens reported as having no endocervical component on SurePath (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) liquid-based, thin-layer technology at an academic center cytology laboratory. STUDY DESIGN: Analysis of 511 cases lacking endocervical/transformation zone component out of 9,221 SurePath thin-layer gynecologic specimens processed in a one-year period. The study encompassed a review of sample collection techniques by physicians and nurses, specimen processing, cytologic features of endocervical/squamous metaplastic cells processed by the SurePath method and statistical analysis of endocervical cell recovery rates after implementation of corrective measures. RESULTS: Absence of endocervical/transformation zone component varied from an initial 18% in the first month to an average of 5.3% after corrective actions were implemented. Current rates of SurePath thin-layer specimens having no endocervical component are lower than those for conventional smears. CONCLUSION: Since SurePath was only recently introduced to the market, there are no previously published data addressing how to optimize the recovery of endocervical component on liquid-based, thin-layer specimens processed by this methodology.     

Polyomavirus infection versus high-grade bladder carcinoma. The importance of cytologic and comparative morphometric studies of plastic-embedded voided urine sediments

The cytodiagnostic criteria of polyomavirus infection of the urinary tract versus high-grade bladder carcinoma in Cytospin and plastic-embedded preparations of voided urine samples are presented. In Cytospin preparations, the polyomavirus infection and the high-grade bladder carcinoma could not always be distinguished from each other. The diagnosis was facilitated when plastic-embedded specimens were used for cytologic study. On the basis of the comparison of morphometric data from the two types of specimens, it is postulated that the physical properties of the cancer cell nuclei differ from those of the virocytes.     

The effects of cytocentrifugation on differential cell counts in samples obtained by bronchoalveolar lavage

Quantification of the differential cell count and total number of cells recovered from the lower respiratory tract by bronchoalveolar lavage is a valuable technique for the diagnostic study of interstitial lung diseases. To examine the effect on the cell counts of different methods of processing the lavage fluid, two comparisons were performed. First, two methods of differential cell counting were compared using 28 fluids. One count was performed in a Malassez hemocytometer after incubation of the living cells with neutral red for five minutes at room temperature; large cells and some small cells that had incorporated neutral red were identified as macrophages. Another count was performed on cytocentrifuge preparations made using the Shandon Cytospin I and Cytospin II and stained by the May-Grünwald-Giemsa method. The percentage of cells identified as lymphocytes was significantly lower on the cytocentrifuge preparations than with the Malassez hemocytometer. In the second study, the differential cell counts on smears prepared by the two types of cytocentrifuge (Cytospin I and Cytospin II) were compared for 32 bronchoalveolar lavage fluids. The percentage of small cells (especially lymphocytes) was lower on preparations made with the Cytospin I than on those made with the Cytospin II, but the difference was not significant. The results indicate that (1) cytocentrifugation of bronchoalveolar lavage fluids does result in a significant loss of small cells, especially lymphocytes, and (2) this loss is not significantly lessened by the use of the Cytospin II.     

Confocal microscopy: principles and applications to the field of reproductive biology

Confocal microscopy allows analysis of fluorescent labeled thick specimens without physical sectioning. Optical sections are generated by eliminating out-of-focus fluorescence and displayed as digitalized images. It allows 3-dimensional reconstruction (XYZ) and time-analysis (XYT), thus providing unique chance to link morphology with cell function. Since images are obtained by scanning, excess illumination of the specimen and quick decrease of the fluorescent signal are avoided. Resolution obtained with a Laser Scanning Confocal Microscopy (LSCM) is theoretically better than that of a conventional microscope. The preparation of the specimen may be based on standard techniques, such as immunocytochemistry applied to fixed cells, or on staining of living cells, following the use of different fluorescent probes at the same time (colocalization). In our laboratory, we use the LSCM system Fluoview version 2.1 (Olympus) to study reproductive biology of animals and humans. We work on stainings of oocytes and blastocysts (mouse, bovine, human), and human ovarian tissues. We study mitochondrial distribution, cortical granule migration, calcium oscillations and spindle quality to link culture conditions and oocyte quality. Staining of F-actin is used to check transzonal projections (in zona pellucida) or to detect abnormalities following experimental treatment. Blastocyst quality is analyzed in sequential optical sections for microfilament organization and counting of total cell number (staining with phalloidin (actin) and picogreen (DNA). Trophectoderm and inner cell mass distribution (differential staining), apoptotic cells (TUNEL method) and viable cells (live/dead test) are also evaluated. Confocal imaging can be helpful for rapid determination of follicle density (staining with AM Calcein) and follicle morphology (picogreen) in ovarian cortical biopsies. The current review describes the principles of confocal microscopy and illustrates its applications to the field of reproductive biology by a large collection of pictures.