Factor analysis of confocal image sequences of human papillomavirus DNA revealed with fast red in cervical tissue sections stained with TOTO-iodide.

OBJECTIVE: To visualize and localize specific DNA sequences by fluorescence in situ hybridization, confocal laser scanning microscopy (CLSM) and factor analysis of biomedical image sequences (FAMIS). STUDY DESIGN: Human papillomavirus (HPV) DNA was identified in cervical tissue sections with biotinylated DNA probes recognizing the whole genome of HPV DNA types 18 and 16, and DNA-DNA hybrids were revealed by streptavidin-alkaline phosphatase and Fast Red (FR). Cell nuclei were counterstained with TOTO-iodide. Image sequences were obtained using successive dynamic or spectral sequences of images on different optical slices from CLSM. The location of fluorescent signals inside tissue preparations was determined by FAMIS and/or selection of filters at emission. Image sequences were summarized into a reduced number of images, called "factor images," and curves, called "factors." Factors estimate spectral patterns and depth emission profiles. Factor images correspond to spatial distributions of the different factors. RESULTS: We distinguished between FR and nucleus staining in HPV DNA hybridization signals by taking into account differences in their spectral patterns and improved visualization by taking into account differences in their focus (depth emission profiles). CONCLUSION: FAMIS, together with CLSM, made possible the detection and characterization of HPV DNA sequences in cells of cervical tissue sections.

Four-dimensional factor analysis of confocal image sequences (4D-FAMIS) to detect and characterize low copy numbers of human papillomavirus DNA by FISH in HeLa and SiHa cells.

Visualization and localization of specific DNA sequences were performed by fluorescence in situ hybridization, confocal laser scanning microscopy (CLSM), and four-dimensional factor analysis of biomedical image sequences (4D-FAMIS). HeLa and SiHa cells containing, respectively 20-50 and 1-2 copies per cell of human papillomavirus (HPV) DNA type 18 and 16 integrated in cellular DNA were used as models. HPV-DNA was identified using DNA probes containing the whole genome of HPV-DNA type 18 or 16, and DNA-DNA hybrids were revealed by alkaline phosphatase and Fast Red. Cell nuclei were counterstained with thiazole orange (TO) or TOTO-iodide. 4D image sequences were obtained using successive dynamic or spectral sequences of images on different optical sections from CLSM. The location of fluorescent signals within the preparations was determined by FAMIS. This original method summarizes image sequences into a reduced number of images called factor images, and curves called factors. Factors estimate different individual physical behaviours in the sequence such as extinction velocity, spectral patterns and depth emission profiles. Factor images correspond to spatial distributions of the different factors. We distinguished between Fast Red and nucleus stainings in HPV-DNA hybridization signals by taking into account differences in their extinction velocities (fluorescence decay rate) or spectral patterns, and in their focus (depth emission profiles). In HeLa cells, factor images showed that Fast-Red-stained targets could be distinguished from nucleus stainings, and were located on different focal planes of the nuclei. In SiHa cells, 4D-FAMIS determined as few as 1-2 copies per cell of HPV-DNA type 16 located in continuous focal planes. Therefore, 4D-FAMIS, together with CLSM, made the detection and characterization of low copy numbers of genes in whole cells possible.

Morphological analysis of in situ hybridization signals in cervical intraepithelial neoplasia containing human papillomavirus type 16 or 18: relationship with histological grade and DNA content.

Among 345 lesions histologically defined as cervical intraepithelial neoplasia (CIN) examined by in situ hybridization (ISH) for the presence of DNA from human papillomavirus (HPV) types 6/11, 16, 18, 31, 33, and 51, a group of 69 lesions (41 low grade and 28 high grade) containing HPV 16 or 18 was further characterized with the following criteria: DNA ploidy and morphological patterns of ISH spots, i.e., punctate or diffuse throughout the nuclei corresponding to integrated or episomal state of HPV DNA, respectively. The highest percentage of aneuploid lesions, the highest diploid index values, and the highest proportion of CIN with punctate ISH signals were associated with high-grade lesions. In addition, punctate ISH signals were also most frequently found in aneuploid CIN. These results underline that punctate ISH signals considered as integrated HPV DNA were preferentially associated with aneuploid and high-grade lesions, and lead to suggest that this later criteria could be used to predict the evolution of a lesion towards malignancy.

Detection of low copy numbers of HPV DNA by fluorescent in situ hybridization combined with confocal microscopy as an alternative to in situ polymerase chain reaction.

In genital lesions infected by human papillomavirus (HPV), histological criteria and HPV DNA typing are of prognostic value. Therefore, non-radioactive methods such as in situ hybridization are used extensively since they preserve the histological organization of the tissue, and allow the detection and characterization of HPV DNA. However, the sensitivity of these methods is often limited to detection of low copy numbers of HPV DNA in isolated cells or in tissue sections, and therefore alternative techniques have been explored. In the present study, 1-2 copies of HPV DNA were visualized in SiHa cells either by in situ amplification of nucleic acid sequences with the polymerase chain reaction (PCR) or by fluorescent in situ hybridization (FISH) associated with observation by laser scanning confocal microscopy (LSCM). The latter procedure was evaluated for use on histological tissue sections to identify low copy numbers of HPV DNA. Genital lesions which were negative by enzymatic in situ hybridization and FISH but histologically suspected of HPV infection were investigated, and intense signals were obtained both with in situ PCR and with the combined use of FISH and LSCM. Therefore, the combination of FISH with LSCM examination may be as valuable as in situ PCR to detect viral genes present in small amounts in isolated cells and in tissue sections.

Laser scanning confocal microscopy and factor analysis of biomedical image sequences (FAMIS) to detect and characterise HPV DNA sequences by FISH in HeLa cells.

Visualisation and localisation of specific DNA sequences were performed by fluorescence in situ hybridisation (FISH), confocal laser scanning microscopy (CLSM), and factor analysis of biomedical image sequences (FAMIS). HeLa cells containing 10-50 copies per cell of human papillomavirus (HPV) DNA type 18 integrated in cellular DNA were used as a model. HPV-DNA was identified by DNA probes and DNA-DNA hybrids were revealed by alkaline phosphatase and Fast Red (FR) TR salt/naphtol-MX phosphate. Cell nuclei were counterstained with thiazole orange (TO). FAMIS summarises image sequences into a reduced number of images called factor images and curves called factors. Factor images correspond to spatial distributions of the different factors. Factors estimate different individual physical behaviours in the sequence (extinction velocity, spectral emission, depth emission profiles). We verified that HPV-DNA hybridisation signals are specific to the spectrum of FR, and distinguished between FR and TO. The latter result was found by taking into account differences in their extinction velocities. The focus of CLSM was improved on 3D image sequences, and the location of fluorescent signals inside the preparations was determined. Factor images showed that FR stained targets were located on different focal planes at the periphery of the nuclei.

Detection of human papillomavirus DNA in genital lesions by enzymatic in situ hybridization with Fast Red and laser scanning confocal microscopy.

Human papillomavirus (HPV) infection with potentially oncogenic types 16 or 18 is common in genital lesions especially in uterine carcinomas. In such lesions, in situ hybridization with non-radioactive probes is a powerful tool for the histopathologist to detect and type HPV DNA either on cell deposits or on tissue sections. The use of an immunohistochemical method involving alkaline phosphatase and Fast Red TR salt/naphthol AS-MX phosphate is proposed for use with conventional bright-field or fluorescence microscopy as well as by laser scanning confocal microscopy. The alkaline phosphatase-Fast Red reaction has the advantage of producing a red precipitate that permits the detection of in situ hybridization signals by bright-field microscopy, and of obtaining a strong red fluorescence characterized by a lack of bleaching when excited by a green light. Therefore, the alkaline phosphatase-Fast Red reaction is well adapted for observations by fluorescence and confocal microscopy, the latter method allowing the detection, in tissue sections of cervical intraepithelial lesions, of small punctate and large diffuse hybridization signals, considered as integrated and episomal states of HPV DNA respectively. The combination of in situ hybridization with the alkaline phosphatase-Fast Red reaction and confocal microscopy is particularly convincing when hybridization signals are of small size and/or of low fluorescence intensity, especially if they are present in various focal planes; in such conditions, infected cells are easily detected by three-dimensional reconstruction. Therefore, this combination is a suitable method for identifying and characterizing HPV DNA in cells and tissue sections.

External anogenital lesions in organ transplant recipients. A clinicopathologic and virologic assessment.

BACKGROUND AND DESIGN: In a series of patients treated at a university department of dermatology, we assessed the clinicopathologic features of external anogenital lesions in organ transplant recipients. For 6 years, 1002 recipients with various dermatologic problems underwent assessment for the presence of proliferative external anogenital lesions; these lesions were examined histologically and virologically for the presence of human papillomaviruses (HPV). RESULTS: Twenty-three patients (2.3%) presented with anogenital lesions, women being more often involved. Clinicopathologic examination revealed 18 anogenital warts, 3 cases of bowenoid papulosis, 1 giant condyloma, and 1 in situ carcinoma. Other viral coinfections were frequent. The lesions were extensive and refractory to treatment in 13 patients, but lesions in 7 were cured alter the immunosuppressive treatment was tapered of discontinued. Dysplastic changes were frequent on histologic examination. Twenty-one lesions contained HPV; 6 of 13 patients with HPV DNA in their lesions harbored oncogenic types that predominated in dysplastic lesions. In some patients, the same HPV types were detected within cutaneous and anogenital lesions, suggesting self-contamination. CONCLUSIONS: External anogenital lesions are more rare than cutaneous lesions in organ transplant recipients. These lesions may represent a marker of immunosuppression, especially when they are extensive. Their clinical aspect is often misleading; furthermore, because of the presence of dysplastic histologic aspects and oncogenic HPV types, they could be susceptible to malignant transformation, necessitating regular surveillance.

Comparative evaluation of the antiproliferative effect of cyclosporin A and gamma-interferon on normal and HPV-transformed keratinocytes by cell counting, MTT assay and tritiated thymidine incorporation.

We compared three techniques, the MTT tetrazolium assay, cell counting, and tritiated thymidine ([3H]TdR) incorporation assay to measure the antiproliferative effect of cyclosporin A (CsA) and interferon-gamma (IFN-gamma) on normal human skin keratinocyte cultures (NHK) used at the second passage and human papilomavirus type 16- and 18-transformed cell lines (EK16 and EK18) exposed continuously to the drugs for 3 days. The three techniques showed that under CsA (0.5 and 8 micrograms/ml) and IFN-gamma (5 and 160 U/ml) treatments the cells remained viable and that the growth of keratinocytes was inhibited. For IFN-gamma, the MTT colorimetric assay consistently underestimated its growth inhibitory activity as compared to cell counting or [3H]TdR incorporation, whatever the cells used. For high doses of CsA, MTT and cell counting gave similar percentages, of inhibitory activity whatever the cells; MTT underestimated this activity as compared to [3H]TdR incorporation only in NHK and EK18 cells, whereas similar results were obtained with EK16 cells. In conclusion, this investigations shows that MTT sensitivity differed with the drug and also according to the keratinocyte cultures. The MTT test is clearly not appropriate for study of IFN-gamma treatment whatever the keratinocytes used. Such discrepancies indicate that the MTT test should be done with care on cultures to measure the effects of drugs on cell growth; the growth inhibition should be carefully considered and it would be best if two different methods were used.

Differences in responses of interleukin-1 and tumor necrosis factor alpha production and secretion to cyclosporin-A and ultraviolet B-irradiation by normal and transformed keratinocyte cultures.

Among epidermal cytokines, IL-1 and TNF alpha are involved in inflammatory skin reactions and suspected of modulation by immunosuppressive treatment (e.g., cyclosporin A, CsA) or UVB-irradiation, 2 mediators probably being involved in epithelial carcinogenesis. We evaluated the effects of 8 micrograms/ml CsA and 100 J/m2 UVB-irradiation on the production and secretion of IL-1 and TNF alpha on normal human epidermal keratinocytes (NHK) and epidermal keratinocyte cell lines either spontaneously transformed (HaCaT) or transformed by human papillomavirus (HPV) type 16 or 18 (EK 16 and EK18), by using ELISA test. Normal and immortalized keratinocytes constitutively produced and released IL-1 alpha, IL-1 beta and IL-1 receptor antagonist (IL-1RA) but IL-1 synthesis by NHK was significantly higher than by cell lines. All the cells spontaneously excreted low amounts of TNF alpha. Different responses to treatments were evidenced between NHK and cell lines. CsA modified significantly the production and secretion of IL1 in most cells whereas slight changes were observed with TNF alpha secretion. UVB irradiation had no effect on the intracellular IL1 pool of any cells but increased the release of IL1 and TNF alpha. The association CsA-UVB did not result in additive effects on synthesis and secretion of IL1; the release of TNF alpha by the cells remained poor except for EK18 cells. Taken together, these results show that, in immortalized keratinocytes, the IL-1 and TNF alpha expression was differently affected by treatments with CsA and/or UVB-irradiation as compared to NHK. In addition, spontaneously transformed keratinocytes, HaCaT, reacted differently from HPV-transformed keratinocytes, EK16 and EK18.

Incidence of human papillomavirus type 33 in premalignant and malignant skin lesions from organ transplant recipients.

Human papillomavirus (HPV) type 33 belongs to potentially oncogenic types in genital cancers, but its infection corresponds to an intermediate risk for progression towards malignancy. We studied by in situ hybridization with biotinylated probes the incidence of HPV 33 infection in a series of 106 skin lesions and 12 mucosal lesions from heart and renal transplant recipients, 34 skin lesions and 17 mucosal lesions from normal population. We have shown that skin lesions from both populations could harbor HPV 33. In transplant recipients, HPV 33 was identified in 12/77 premalignant and malignant lesions and one oral leukoplakia; in the normal population, HPV 33 was detected in 2/13 warts and 2/15 mucosal lesions. The analysis of in sial hybridization signal pattern of the 17 HPV 33 positive samples suggests that a strong viral DNA signal was uniformly distributed in the nuclei of positive cell foci in 11 cases and punctate signals were seen in the nuclei of dispersed cells of 6 skin biopsies. The significance of the presence of HPV 33 DNA in skin lesions is not clear; the hybridization signal pattern may be important, mainly in premalignant actinic keratodses of organ transplant recipients although other factors are most likely involved to change the epithelial environment.

Differences in reactivity to cyclosporin A and interferon-gamma of normal and HPV-transformed keratinocytes.

In humans, cyclosporin A (CsA) avoids organ allograft rejection but induces skin carcinomas after long term immunosuppressive treatment; some of these lesions contain human papillomavirus (HPV) DNA. Interferon-gamma (IFN-gamma) is sometimes used in local treatment of persistent or recurrent lesions in normal population. In vivo, both drugs have an effect on keratinocytes which remains unclear. Therefore, their effect was studied on in vitro models of normal or HPV-transformed epithelial cell cultures. After exposure of proliferating cells for 1-3 days to 0.5-16 micrograms/ml CsA and 5-160 U/ml IFN-gamma, no cytotoxicity was observed; cell growth was inhibited; cell morphology was altered with CsA and cytoplasmic vacuoles were seen in some cells. Changes in the cell cycle were mainly obtained after treatment with 8 micrograms/ml CsA or 160 U/ml IFN-gamma, with an accumulation in S-phase especially in HPV-transformed cells. Thus, CsA and IFN-gamma affected, normal and HPV-transformed epithelial cells, differently.

A possible role for human papillomaviruses and c-myc, c-Ha-ras, and p53 gene alterations in malignant cutaneous lesions from renal transplant recipients.

Several years after transplantation, renal transplant recipients develop numerous cutaneous squamous cell carcinomas (SCC), in which human papillomaviruses (HPV) may be detected. Alterations in c-myc, c-Ha-ras, and p53 genes were studied in 34 SCC, in correlation with the presence of HPV. In situ hybridization (ISH) and polymerase chain reaction (PCR) showed that many SCC contained several HPV types infecting different foci of epithelial cells. Using Southern blot and ISH, c-myc and/or c-Ha-ras gene amplification was detected in 7/13 SCC tested. With PCR and oligoprobe hybridization, a GGC -> GAC mutation was found at codon 12 of c-Ha-ras gene in 1/21 SCC tested, while no mutation was detected at codon 61. Using immunohistochemistry, p53 protein expression was detected either along the basal cell layer or spotted in foci of basal cells. Our results show an abnormal distribution of HPV types in SCC from renal transplant recipients, and alterations of c-myc, c-Ha-ras, and p53 genes without any direct link with the presence of any studied HPV type. Thus, viral infection and oncogene activation may represent factors involved in the etiology of skin SCC from transplant recipients.

Differences of reactivity to interferon gamma in HeLa and CaSki cells: a combined immunocytochemical and flow-cytometric study.

We characterized the changes induced by treatment for 48 h with 100 U/ ml interferon gamma (IFN-gamma) on HeLa and CaSki cells, derived from human uterine carcinomas and containing human papillomavirus (HPV) type 16 and HPV type 18 respectively, by studying cell growth, cell morphology, the cell cycle and expression of epidermal growth factor (EGF) receptor, filaggrin-profilaggrin and MHC class II antigen, HLA-DR. The response of the two cell lines to IFN gamma differed in some cases. In both cell lines, the cells remained viable; cell growth was similarly inhibited as shown by cell counts. Signs of morphological changes were essentially observed in HeLa cells. The cell cycle phases, analyzed by flow cytometry were more disturbed in CaSki than in HeLa cells; the proportion of CaSki cells in S phase increased and those in G2 + M decreased. Expression of EGF receptors related to proliferation increased only in CaSki cells while expression of filaggrin-profilaggrin, a marker of differentiation, and HLA-DR, a marker of epithelial cell immune response, was enhanced in both cell lines. The presence of filaggrin-profilaggrin being unexpected in these cells, the specificity of the reaction with the monoclonal antibody AKH1 was confirmed by immunoblotting. In conclusion, our results show that the two cell lines reacted differently to IFN gamma although they are of similar origin and the different antigens studied may be useful to predict the progression of lesions infected with HPV towards malignancy or the reactivity to IFN gamma of such lesions. However, enhanced synthesis of EGF receptors is probably independent of the antiproliferative effect of IFN gamma but an increase in HLA-DR antigen expression by epithelial cells, which corresponds to an immune response favored by IFN gamma, could act synergistically with cell growth inhibition and differentiation to exclude tumoral and/or HPV-infected cells.

Analytical methods for evaluation on whole cells of human papillomavirus infection.

Analytical methods for evaluation on whole cells of human papillomavirus infection. Human papillomavirus (HPV) infection is currently identified by the presence of viral DNA using molecular biology. As in situ hybridization is valuable for HPV-DNA detection mainly with non-isotopic probes, we evaluated the sensitivity of various techniques, using as models three cell lines containing different copy numbers of HPV DNA/cell (CaSki with 600 copies of HPV 16, SiHa with 1-2 copies of HPV 16, HeLa with 10-50 copies of HPV 18). Epifluorescence microscopy and flow cytometry allowed detection of 600 copies in CaSki cells; in addition, cell fixation was found to influence the fluorescent intensity. Several procedures were assayed to increase the sensitivity of in situ hybridization. The use of biotinylated HPV-16 oligonucleotides as probes was not effective, because only CaSki cells were positive. After amplification of HPV-16 or -18 DNA sequences with polymerase chain reaction (PCR) on whole cells in suspension and hybridization with plasmid probes, fluorescent hybridization spots were found in CaSki and HeLa cells by both epifluorescence microscopy and flow cytometry. The various procedures applied for revelation of DNA-DNA hybrids (use of phycoerythrin or cyanine instead of fluorescein, Pinkel's 3-step amplified system of fluorescein) did not enhance the sensitivity of in situ hybridization. HPV DNA was very effectively detected by cell examination under a laser-scanning confocal microscope, since 1-2 copies of HPV 16 were observed in SiHa cells without previous PCR amplification. Thus, the efficacy of in situ hybridization for HPV detection may be conditioned by different factors. Laser-scanning microscopy represents an alternative to the use of PCR amplification. These techniques are potentially useful to study single genes.

Active cell membrane mechanisms involved in the exclusion of Rh 123 allow distinction between normal and tumoral cells.

Human cell lines derived from three epithelial carcinomas (CaSki, HeLa, SiHa), one B lymphoma (BL60), one promyelocytic (HL60), one monocytic (U937) leukemia, one chronic myelogenous leukemia (sensitive K562S; multichemoresistant K562R) and normal human skin fibroblasts were compared for their capacity of staining with rhodamine 123 (Rh 123) and their kinetics of dye exclusion. Cells were exposed for 30 min to 10 micrograms/ml of Rh 123 in culture medium; fluorescence intensity was measured by flow cytometry immediately or 1, 2, 3 and 4 h after staining. The highest fluorescence intensity was observed in carcinoma cell lines; there was no incorporation in multichemoresistant K562R cells. Exclusion of Rh 123 was evaluated from 0 to 4 h, both by flow cytometry and by fluorimetry. Fluorescence intensity measured by flow cytometry decreased slightly in carcinoma and leukemia cells and rapidly in fibroblasts. In all cell lines Rh 123 exclusion was inhibited by 40 mumol/L verapamil and 5 mmol/L probenecid. Thus, incorporation and exclusion of Rh 123 allows distinction between normal and tumoral cells; moreover, inhibition of exclusion by verapamil and probenecid favors the involvement of active cell membrane mechanisms in the exclusion process.

Improvements in visualisation and localisation of human papillomavirus DNA in CaSki cells by fluorescence in situ hybridization, laser scanning confocal microscopy and three-dimensional image reconstruction.

The visual interpretation and localisation of specific DNA sequences in three dimensions in cell nuclei was investigated by fluorescence in situ hybridization (FISH) and laser scanning confocal microscopy (LSCM) using CaSki cells containing 600 copies per cell of human papillomavirus (HPV) DNA type 16 integrated in cellular DNA. Biotinylated DNA probes were used and DNA-DNA hybrids were revealed by a three-step reaction involving a rabbit anti-biotin antibody, a biotinylated goat anti-rabbit antibody and a streptavidin-fluorescein isothiocyanate complex. The DNA from cell nuclei was counterstained with propidium iodide. With standard fluorescence microscopy, some dense fluorescent spots were seen in the cell nuclei. Similarly, with LSCM, some hybridization spots were observed in the cell nuclei but they were at different levels of the nuclei as shown by successive nuclear sections taken along the z axis. The visualisation of multiple hybridization spots confirmed the presence of multiple integration sites of HPV 16 DNA in CaSki cells. Association of LSCM with three-dimensional reconstructions lead to spatial images of hybridization spots obtained by stacking (x,y) images from consecutive confocal planes. Rotation of the reconstructed cell nuclei around the y axis makes it possible to distinguish closely adjacent spots. The combination of these techniques improves the detection of hybridization spots and may be of interest to further determine whether the HPV DNA is episomal or integrated in infected cells.

[Detection of human papillomavirus DNA by in situ hybridization and gene amplification]. / Détection d'ADN de papillomavirus humains par hybridation et amplification génique in situ.

In situ hybridization with non radioactive probes is attractive for human papillomaviruses (HPV) detection. Its sensitivity has been greatly improved by using different hybridization conditions, techniques for revealing the DNA-DNA hybrids and method of observation and various cell lines derived from human uterine carcinomas (CaSki, SiHa and HeLa cells) which contain 500-600 copies of HPV DNA, 1-2 copies of HPV 16 and 20-50 copies of HPV DNA 18, respectively. In situ gene amplification increased the detection of HPV DNA since hybridization spots were visible in SiHa cells on slides; a specific signal was observed in HeLa cells in suspensions examined by flow cytometry. Confocal microscopy is an alternative method to in situ gene amplification since viral DNA is detectable in SiHa cells with or without gene amplification. Thus, the techniques used in this study are potentially useful for research of single cellular genes.

Immunohistochemical studies on c-erbB-2 oncoprotein expression in paraffin embedded tissues in invasive and non-invasive human breast lesions.

The c-erb-B2 protein expression was evaluated by immunohistochemistry in two series of breast lesions. In a retrospective study on a series of 140 breast lesions, among 34 benign lesions, 16 showed an intense or moderate membrane reaction of tumoral cells; of 15 atypical lesions, 6 exhibited a membrane reaction and 34/60 in situ lesions expressed intensely or moderately c-erb-B2 oncoprotein. A prospective investigation was made on a series of 41 lesions from 25 patients, which were selected for their clinico-pathological features. All the samples were positive but the staining intensity was heterogenous. However, it was similar in the various lesions from the same patient. A strong signal was observed in 12 lesions from 7/25 patients, moderate in those of 13 patients and weak in 6 lesions from 5 patients. Taken together, our findings show that a large number of human breast lesions expressed c-erb-B2 oncoprotein, whether benign, atypical or in situ carcinomas. The intensity of the reaction may depend on the patients rather than on the aggressivity of the lesion, except for the infiltrating carcinomas. This suggests that c-erb-B2 oncoprotein in overexpressed at early stages of breast cancer lesions. Although c-erb-B2 oncoprotein is probably not a good marker for prognosis, it may be an indication for a future progression towards or recurrence.

Laser scanning confocal microscopy and quantitative microscopy with a charge coupled device camera improve detection of human papillomavirus DNA revealed by fluorescence in situ hybridization.

Epithelial cervical CaSki, SiHa and HeLa cells containing respectively 600 copies of human papillomavirus (HPV) DNA type 16, 1-2 copies of HPV DNA type 16 and 10-50 copies of HPV DNA type 18 were used as model to detect different quantities of integrated HPV genome. The HPV DNA was identified on cell deposits with specific biotinylated DNA probes either by enzymatic in situ hybridization (EISH) or fluorescence in situ hybridization (FISH) involving successively a rabbit anti-biotin antibody, a biotinylated goat anti-rabbit antibody and streptavidin-alkaline phosphatase complex or streptavidin-fluorescein isothiocyanate complex. With brightfield microscopy and EISH, hybridization spots were observed in CaSki and HeLa cells but hardly any in SiHa cells. With fluorescence microscopy and FISH, hybridization spots were clearly seen only on CaSki cell nuclei. In an attempt to improve the detection of low quantities of HPV DNA signals revealed by FISH, laser scanning confocal microscopy (LSCM) and quantitative microscopy with an intensified charge coupled device (CCD) camera were used. With both LSCM and quantitative microscopy, as few as 1-2 copies of HPV DNA were detected and found to be confined to cell nuclei counterstained with propidium iodide. Under Nomarski phase contrast, a good preservation of the cell structure was observed. With quantitative microscopy, differences in the number, size, total area and integrated fluorescence intensity of hybridization spots per nucleus were revealed between CaSki, SiHa and HeLa cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Pseudo oral hairy leukoplakia in a renal allograft recipient.

Oral hairy leukoplakia (OHL) is a disorder of the tongue associated with Epstein-Barr virus (EBV). OHL is seen mainly in HIV infection but is also rarely seen in the course of iatrogenic immunosuppression, especially in kidney transplantation; OHL is even more rarely seen in immunocompetent hosts. Lesions that clinically and histologically mimicked OHL but were not associated with EBV were recently characterized as pseudo hairy leukoplakia. We present such a case that occurred in a renal allograft recipient; light and electron microscopy, immunohistochemistry, and in situ hybridization were used to examine the patient for the presence of EBV and human papillomavirus. Two independent treatments with topical retinoid and oral amoxicillin resulted in complete remission. Pseudo hairy leukoplakia may correspond, at least in some cases, to the conditions known as leukoedema and white sponge nevus; the distinction of these diseases from OHL is of importance because OHL is a hallmark of severe immunosuppression.