The use of general primers GP5 and GP6 elongated at their 3' ends with adjacent highly conserved sequences improves human papillomavirus detection by PCR

Sequence analysis of human papillomavirus (HPV) general primer GP5/6 mediated PCR products revealed the presence of short highly conserved sequences adjacent to the 3' ends of both primers. Part of these sequences was used to elongate GP5 and GP6 at their 3' ends to generate the primers GP5+ and GP6+, respectively. Compared with the GP5/6 PCR, GP5+/6+ specific PCR on 22 cloned mucosotropic HPVs revealed an improved HPV detection, reflected by a 10- to 100-fold higher sensitivity and a markedly increased signal to background ratio, especially at the gel level. As determined on purified DNA, the sensitivity of this GP5+/6+ based assay was at the femtogram level for those HPV genotypes which match strongly with the primers (e.g. HPV-16) and at the picogram level for HPV types (e.g. HPV-39 and -51) having four or more mismatches with one or both primers. Application of both methods on 264 cervical scrapes of a cohort of women participating in a prospective follow-up study revealed an increase of total HPV positivity from 39% (GP5/6 PCR) to 43% (GP5+/6+ PCR) of the scrapes. Additional HPV typing by PCR specific for the HPV-6, -11, -16, -18, -31 and -33 revealed that all GP5+/6+ PCR positive cases which were negative by GP5/6 PCR (n = 12) contained HPV types different from these six types. These data indicate that the GP5+/6+ PCR method provides an increased detection level mainly of uncommon, apparently poorly matched HPV types in cervical scrapes and most likely in the enlargement of the spectrum of HPVs detectable by this assay.

Group-specific differentiation between high- and low-risk human papillomavirus genotypes by general primer-mediated PCR and two cocktails of oligonucleotide probes

In recent years, general primer-mediated PCR assays have been developed to detect a broad spectrum of human papillomavirus (HPV) genotypes. In this study, a procedure enabling a simple group-specific differentiation of high-risk (HPV-16, -18, -31, -33, -35, -39, -45, -51, -52, -54, -56, and -58) and low risk (HPV-6, -11, -34, -40, -42, -43, and 44) HPVs following an HPV general primer-mediated (GP5+/GP6+) PCR is presented. By computer-assisted sequence analysis, oligonucleotides (30-mers) specific for 19 different HPV genotypes were selected from the internal part of the 150-bp GP5+/GP6(+)-amplified region. These oligo probes were tested for specificity in a Southern blot analysis of PCR products derived from the same panel of HPV types. No cross-hybridizations were found. The sensitivities of the oligo probes varied from the femtogram level for the well-amplified HPV types like HPV-16 and -18 to the picogram level for the less-well amplified HPV types like HPV-39 and -51. These sensitivities were reached when the oligo probes were applied both individually and in a cocktail. On the basis of these results, two cocktail oligo probes that enabled a specific and sensitive differentiation between low- and high-risk HPV types were composed.

Localization and identification of granzymes A and B-expressing cells in normal human lymphoid tissue and peripheral blood

Cytoplasmic granules from activated natural killer (NK) and cytotoxic T lymphocytes (CTL) contain a pore-forming protein, perforin, and several homologous serine proteinases called granzymes. Expression of these proteins correlates with the cytolytic potential of cytotoxic lymphocytes. Using a panel of MoAbs specific for human granzyme A and B, respectively, expression of these proteinases in non-pathological lymphoid tissue and peripheral blood lymphocyte (PBL) subpopulations was investigated. Using immunohistochemistry and double stainings, the phenotype of granzyme-expressing cells in lymphoid tissue was investigated. Granzyme-positive cells were detected in all lymphoid tissues tested. No large differences in the number and distribution between granzyme A- and granzyme B-positive cells were observed. The highest number of positive cells was located in the red pulp of the spleen. Significant numbers were detected in tonsil, lymph nodes, liver and thymus. Low numbers were present in the lamina propria of non-inflamed stomach, small intestine and colon. Phenotypic analysis and cell sorting showed that most of the granzyme-positive cells in lymphoid tissue and PBL consisted of CD3-CD16+CD56+ lymphocytes. Hardly any granzyme-positive CD3+CD8+ CTL were present in peripheral blood. The synthesis of granzyme A as well as B by both CD3+CD16+CD56+ and CD3+CD8+ cells in peripheral blood was increased upon IL-2 stimulation. These results indicate that in normal lymphoid tissue the predominant cytolytic cell population is formed by the NK cells, and activated CTL are rare.

Epstein-Barr virus in primary gastrointestinal T cell lymphomas. Association with gluten-sensitive enteropathy, pathological features, and immunophenotype

Forty-three primary gastrointestinal T cell lymphomas were investigated for the presence of Epstein-Barr virus (EBV) by polymerase chain reaction, RNA in situ hybridization, and immunohistochemistry. In addition, the association between EBV and clinicopathological characteristics of these lymphomas was investigated. Five of the thirty-eight cases that could be evaluated expressed EBV-encoded nonpolyadenylated RNA-1 in most tumor cells. Two of these five cases were EBV latent membrane protein-1 positive. All five cases were CD30 positive. In three of these five EBV-associated T cell lymphomas, the tumor cells were considered to be the neoplastic counterparts of activated cytotoxic T cells as shown by the expression of granzyme B. There was no association with histological characteristics of gluten-sensitive enteropathy, angioinvasion, necrosis, eosinophilia, or epitheliotropism of the tumor cells. The substantial percentage (58%) of EBV DNA polymerase chain reaction-positive cases was largely the result of the presence of EBV-encoded RNA-1-positive reactive cells. In conclusion, EBV might have an important etiological role in only 13% of the primary gastrointestinal T cell lymphomas. This percentage is similar to the findings in primary lymph node and lung T cell lymphomas.

Distribution of extracellular matrix components and their receptors in human lymphoid tissue and B-cell non-Hodgkin lymphomas

In this study the distribution patterns of various extracellular matrix components and their receptors (i.e. beta 1 integrins) in B-cell non-Hodgkin lymphomas were examined and compared to those in reactive lymphoid tissue. Neoplastic follicles within follicular lymphomas showed similar patterns to that observed in reactive follicles, which appeared to be strongly associated with the presence of follicular dendritic cells. Diffuse lymphomas of low and intermediate malignancy grade revealed features comparable to those of interfollicular areas of reactive lymphoid tissue, irrespective to which compartment the tumour cells were related. Highly malignant lymphomas, however, displayed unique extracellular matrix configurations, resulting from active matrix degradation by macrophages; this may support rapid tumour growth. Extranodal lymphomas showed virtually the same matrix patterns as their nodal counterparts, suggesting that (malignant) lymphoid cells generate (at least partly) their own specific microenvironment. In reactive lymphoid tissue beta 1 integrins were mainly found on resident cells and except for alpha 4, alpha 5 (and beta 1) the lymphoid cells expressed very little, if any, beta 1 integrins. In comparison, expression of these integrins on lymphoma cells was reduced (follicular lymphomas) or could not be detected at all (diffusely growing lymphomas); this might contribute to the growth pattern and metastatic properties of the tumours.

Peripheral primitive neuroectodermal tumour and extra-osseous Ewing's sarcoma; a histological, immunohistochemical and DNA flow cytometric study

Although peripheral primitive neuroectodermal tumour (pPNET) and extra-osseous Ewing's sarcoma (EES) are thought to be closely related neoplasms, their clinical behaviour differs considerably. To determine the clinical relevance of the Schmidt classification scheme for differentiating pPNET and EES, 20 tumour specimens of poorly differentiated round cell tumours were evaluated. In addition, the diagnostic value of several neural markers and the prognostic value of quantitative morphological variables (DNA ploidy, S-phase fraction, and the mitotic activity) were assessed. Homer-Wright rosettes were present in 9 tumours. Neuron specific enolase (NSE) was expressed in 11 tumours, 8 of which expressed a second neural marker (CD57, S100, or neurofilament). According to the Schmidt classification, 11 pPNET and 5 EES were distinguished. HBA-71 was exclusively expressed in pPNET and EES. The remaining tumours were classified as sarcoma not otherwise specified (n = 2), rhabdomyosarcoma (n = 1), and desmoplastic tumour with divergent differentiation (n = 1). EES611 patients fared significantly better than the pPNET patients (100% versus 42% 5-year survival). Neither DNA ploidy nor S-phase fraction assessed in 12 evaluative histograms (9 pPNET and 3 EES), nor mitotic activity yielded information of additional prognostic value. On the basis of this study and the Schmidt classification scheme, it can be concluded that if the diagnosis of EES and pPNET is based on light microscopy (Homer-Wright rosettes) and/or immunohistochemistry (at least two neural markers, i.e. NSE, S-100, CD57, and neurofilament), the classification provides important clinical information. Furthermore, positivity for HBA-71 is helpful in differentiating pPNET and EES from all other small round cell tumours.

The expression pattern of contractile and intermediate filament proteins in developing skeletal muscle and rhabdomyosarcoma of childhood: diagnostic and prognostic utility

In order to investigate whether rhabdomyosarcoma (RMS) can be related to equivalent stages of skeletal muscle development, muscle tissue of 21 human foetuses and 112 primary RMSs were characterized immunohistochemically using antibodies directed against vimentin, desmin, muscle-specific actin (HHF35), sarcomeric actin (sr-actin), smooth muscle actin (sm-actin), and troponin-T. During fetal skeletal muscle development, all myotubes/fibres of the first and second generations expressed desmin, HHF35, and sr-actin. Vimentin was almost exclusively present in immature primary and secondary myotubes/fibres. Troponin-T was expressed in immature myotubes/fibres of the first and second generations as well as mature fibres of the second generation. Sm-actin was never expressed. Vimentin was expressed in 96 per cent of primary and 98 per cent of relapsed RMS; HHF35 in 96 and 98 per cent, respectively; desmin in 95 and 100 per cent; troponin-T in 82 and 75 per cent; sr-actin in 71 and 86 per cent; and sm-actin in 13 and 17 per cent. The proportion of RMS cells reacting with vimentin, HHF35, and desmin was consistently higher than those expressing sr-actin and troponin-T. Neither the shape nor size of neoplastic RMS cells nor the histopathological types were related to the expression pattern of the investigated markers. RMS with aberrant expression of two or more markers predicted a worse prognosis than RMS in which at most one marker was aberrantly expressed (25 per cent and 54 per cent 10-year survival, P = 0.01). These results demonstrate that HHF35, desmin, sr-actin, and troponin-T have the potential to confirm the commitment of the tumours to the myogenic pathway which supports the diagnosis of RMS. However, it was impossible to relate RMS to equivalent stages of skeletal muscle development. Aberrant marker expression by RMS cells correlated significantly with patients' survival.

Granzyme B-expressing peripheral T-cell lymphomas: neoplastic equivalents of activated cytotoxic T cells with preference for mucosa-associated lymphoid tissue localization

T-cell non-Hodgkin's lymphomas can be considered the neoplastic equivalents of immunologically functional, site-restricted T lymphocytes. Little is known about the occurrence and clinical behavior of T-cell lymphomas that are the neoplastic equivalents of different functional T-cell subsets. Here, we investigated the prevalence, preferential site, immunophenotype, and clinical behavior of the neoplastic equivalents of activated cytotoxic T cells (CTLs) in a group of 140 nodal and extranodal T-cell lymphomas. Activated CTLs were shown immunohistochemically with a monoclonal antibody against granzyme B, a major constituent of the cytotoxic granules of activated T cells. Granzyme B-positive T-cell lymphomas were mainly found in mucosa-associated lymphoid tissue (MALT; nose, 63% of the cases; gastrointestinal tract, 46%; and lung, 33%). Granzyme B-positive cases with primary localization in MALT were more often associated with angioinvasion (P = .005), necrosis (P = .002), and histologic characteristics of celiac disease in adjacent mucosa not involved with lymphoma. Eosinophilia was more often observed in granzyme B-negative cases (P = .03). Most cases belonged to the pleomorphic medium- and large-cell group of the Kiel classification. CD30 expression was more often found in granzyme B-positive lymphomas of MALT (P = .04), whereas CD56 expression was exclusively found in nasal granzyme B-positive lymphomas. Immunophenotypically, most of the cases should be considered as neoplastic equivalents of activated CTLs based on the presence of T-cell markers on tumor cells. In two cases of nasal lymphoma, tumor cells probably were the neoplastic counterparts of natural killer cells. The prognosis of the granzyme B-positive gastrointestinal T-cell lymphomas was poor but did not differ from granzyme B-negative gastrointestinal T-cell lymphomas. This indicates that, in peripheral T-cell lymphomas, site of origin is more important as a prognostic parameter than derivation of activated CTLs.

Immunohistological and functional analysis of adhesion molecule expression in the rheumatoid synovial lining layer. Implications for synovial lining cell destruction

OBJECTIVE

It has previously been shown that the adhesion of lymphocytes to microvascular endothelium mediates lymphocyte extravasation within inflamed synovium. After passing the endothelial barrier, binding of lymphocytes to matrix proteins and synovial lining cells may further lead to synovial membrane hyperplasia and subsequent cartilage destruction. Thus, we have explored the molecular basis of T cell-synovial lining cell interaction in the synovial membrane of patients with rheumatoid arthritis (RA).

METHODS

Using an immunohistochemical staining technique and an in vitro frozen section assay we studied the expression and the role of several adhesion molecules in T lymphocyte-synovial lining cell interaction in the inflamed synovial membrane.

RESULTS

In RA the macrophage-like (type A) synovial lining cells express high levels of intercellular adhesion molecule 1 [ICAM-1 (CD54)], whereas the fibroblast-like (type B) synovial lining cells predominantly express vascular cell adhesion molecule 1 (VCAM-1), in addition to moderate levels of ICAM-1. Both cell types express low levels of fibronectin. Unstimulated and anti-CD3 stimulated peripheral blood T cells bear the respective ligands lymphocyte function associated antigen 1 [LFA-1 (CD18/11a)], and very late antigen 4 and 5 [VLA-4 (CD29/49d) and VLA-5 (CD29/49e)]. T lymphocytes predominantly bound to type B synovial lining cells. Inhibition studies with monoclonal antibodies revealed that this binding involves the VLA-4/VCAM-1 and VLA-5/fibronectin (FN), but not the VLA-4/CS1 pathway. LFA-1 is also involved in this interaction via its ligand ICAM-1.

CONCLUSION

These results show that the molecular basis of T lymphocyte binding to rheumatoid synovial lining cells is different from that described for T lymphocyte binding to synovial membrane vascular endothelium which involves the VLA-4/VCAM-1 and VLA-4/CS-1 pathways, but not the LFA-1/ICAM-1 pathway.

Analysis of p53 status in tonsillar carcinomas associated with human papillomavirus

Tonsillar squamous cell carcinomas (a total of 14) were examined both for the presence of human papillomavirus (HPV) DNA and for p53 alterations. General primer-mediated HPV polymerase chain reaction (GP-PCR) revealed the presence of HPV DNA in 12/14 cases. Subsequent typing by HPV type-specific PCR and sequence or hybridization analysis of GP-PCR products revealed DNA from HPV 16 in seven cases, from HPV 33 in two cases, and from HPV 7, HPV 16/33 and HPV 33/59 each in a single case. p53 immunohistochemistry performed on nine HPV containing tonsillar carcinomas using polyclonal serum CM-1 showed elevated p53 levels in four cases. These included 3/5 HPV 16 containing carcinomas and the HPV 33/59 containing carcinoma. Analysis of p53 mutations using denaturing gradient gel electrophoresis (DGGE) of GC-clamped PCR products of exons 5 to 8 showed p53 gene alterations in 3/13 cases, including 2/11 HPV positive cases and 1/2 HPV negative cases. The alterations included a silent point mutation within exon 8 of an HPV 16 containing carcinoma, a 1 bp deletion within exon 8 of an HPV 33 containing carcinoma, and a missense mutation within exon 7 of one of the HPV negative carcinomas. There was evident discrepancy between p53 immunohistochemistry and gene analysis. Four HPV containing cases showing elevated p53 levels did not reveal the presence of exon 5 to 8 alterations affecting the amino acid code, suggesting the presence of mutations occurring in other exons or non-mutational p53 stabilization. The data indicate that HPV and elevated p53 can coexist in tonsillar carcinomas and that despite the low frequency of p53 mutations the presence of HPV is not exclusively related to the absence of mutated p53.

Expression of developmentally regulated muscle proteins in rhabdomyosarcomas

Human skeletal muscle differentiation and maturation follows a precise sequence of events. To investigate whether and to what extent rhabdomyosarcoma (RMS) cells follow a comparable sequence, 29 fresh frozen specimens of RMS (14 primary and 15 relapses) were immunostained with antibodies directed against developmentally regulated myosin heavy chains (MHC), ie, fetal, fast, and slow MHC, in addition to desmin and vimentin. Four distinct patterns of expression were observed: I) RMS cells expressing exclusively vimentin and desmin (n = 7), II) in addition to expression of vimentin and desmin, a minority of neoplastic cells were immunoreactive with fetal MHC (n = 6), III) in addition to pattern II, fast MHC was expressed (n = 7), and IV) RMS cells simultaneously expressing vimentin, desmin, fetal, fast, and slow MHC (n = 9). Accordingly, the proportion of the MHC immunoreactive RMS cells increased gradually along with the four patterns of expression evolving from less than 25% up to 75% for fetal MHC, from less than 25% up to 50% for fast MHC, and up to 25% for slow MHC in the last category. Vimentin and desmin were coexpressed by almost all RMS cells. Double immunostaining revealed that comparable with the myogenic cells in the developing fetal skeletal muscle, expression of fetal MHC could be demonstrated in the same neoplastic cells either in conjunction with fast or slow MHC. In contrast, only in RMS, slow MHC expression in conjunction with fast MHC could be observed in the neoplastic cells. Neither the shape or size of neoplastic RMS cells, nor the histopathological types, nor tumor localization were related to the expression pattern of developmentally regulated MHC (fetal, fast, and slow MHC). These results confirm the commitment of the RMS cells to the myogenic pathway and demonstrate a restricted and aberrant differentiation pattern of the neoplastic cells in RMS compared with normal myogenesis, independent of histopathological types of RMS.

Expression of the homeobox gene HOXC4 in keratinocytes of normal skin and epithelial skin tumors is correlated with differentiation

Homeobox (HOX) genes share a highly conserved 183-bp sequence. The encoded proteins are capable of binding to specific DNA sequences and functioning as transcription factors. HOX genes play a critical role in the temporal and spatial differentiation of cells during embryogenesis. In several adult tissues, HOX genes are expressed in a constant, tissue-specific pattern, whereas in malignant tumors of these tissues an altered expression pattern was found. We investigated the expression of HOXC4 in adult normal skin by reverse-transcription polymerase chain reaction and non-radioactive RNA in situ hybridization. Moreover, HOXC4 expression was studied in various epidermal neoplasms (solar keratosis, six specimens; Bowen's disease, four; squamous cell carcinoma, nine; basal cell carcinoma, three) by RNA in situ hybridization. HOXC4 was found to be expressed in the suprabasal layers of the epidermis in normal skin specimens and the adjacent non-lesional epidermis of all other specimens. Atypical keratinocytes of solar keratoses and Bowen's disease as well as basaloid cells of basal cell carcinomas were negative. In squamous cell carcinoma, well differentiated areas with keratinization showed HOXC4 expression, whereas poorly differentiated areas were negative. Immunostaining with an antibody against cytokeratin 10, a marker of epidermal differentiation, was performed. A good correlation between the distribution pattern of HOXC4 and cytokeratin 10 in the lesions examined was found. These results suggest that HOXC4 is expressed mainly in differentiated keratinocytes. Lack of differentiation (as in neoplastic cells) is accompanied by downregulation of HOXC4 expression.

Histopathological classification of childhood rhabdomyosarcomas: relationship with clinical parameters and prognosis

To define a useful and prognostically relevant classification system for rhabdomyosarcomas (RMSs), tissue sections of 113 well-documented, protocol-treated cases were retrieved from the files of the Emma Kinderziekenhuis Amsterdam, the Netherlands, and reclassified by a panel of pediatric pathologists. The following subtypes were recognized: embryonal RMS (n = 66), alveolar RMS (including the solid variant) (n = 16), botryoid RMS (n = 11), embryonal sarcoma (n = 6), and spindle cell RMS (n = 5). Nine cases were classified as RMS not otherwise specified (NOS). The above-mentioned histopathological subtypes correlated significantly with survival (P = .005) in patients with nonparameningeal tumors. Indeed, the best prognosis was observed in patients with spindle cell RMS, embryonal sarcoma, and botryoid RMS (10-year survival rates of 80% to 86%). Patients with embryonal RMS had an intermediate prognosis (10-year survival rate of 55%) and patients with alveolar RMS fared poorly (10-year survival rate of 9%). Survival rate was poor in patients with a localized parameningeal tumor, irrespective of histopathological subtype (10-year survival rate of 33%). Furthermore, this study confirmed the known impact on prognosis of localization (P = .008) and tumor node metastasis (TNM) stage (P = .0005). Classification of RMS subtypes proved to be fairly well reproducible (kappa ranging from 0.47 to 0.85 and percentage of concordance ranging from 50% to 85%). The best agreement was noted in botryoid RMS and the worst in embryonal sarcoma. However, improvement of agreement was noted for the latter subtype during the consecutive classification sessions. In summary, this study shows the strong prognostic value of histopathological subtypes and parameningeal tumor localization.

Decreased expression of cellular markers in Epstein-Barr virus-positive Hodgkin's disease

Epstein-Barr virus (EBV) has been demonstrated in the Reed-Sternberg cells and their mononuclear variants (Hodgkin cells; H-RS cells) in a substantial number of Hodgkin's disease (HD) cases. Moreover, EBV can modulate both in vivo and in vitro the expression of several cellular genes, including lymphoid differentiation markers. Therefore we investigated, in 64 cases of HD, the relationship between the presence of EBV and the expression of lymphoid (CD45RB), T- (CD3, CD45RO), B- (CD20, MB2 antigen, CDw75), and myeloid-cell lineage markers (CD15), and of activation markers (CD30, EMA, and the 115D8 antigen) on the H-RS cells. EBV-positive cases, as demonstrated by the presence of EBER-1 and -2 RNA and LMP-1 protein expression, showed a significant reduction in the expression on H-RS cells of T-cell lineage (CD3, P < 0.02), B-cell lineage (CD20; P < 0.005), and activation markers (EMA; P < 0.002 and the 115D8 antigen; P < 0.001) as compared with EBV-negative cases. No differences were found in the expression of CD15, CD30, CD45RO, CD45RB, CDw75, or the MB2 antigen on H-RS cells in EBV-positive and EBV-negative HD cases. Interestingly, in 11 cases of EBV-negative HD, B- as well as T-cell lineage markers could be found on some H-RS cells. These data suggest that EBV in H-RS cells is able to down-regulate the expression of T- (CD3) and B- (CD20) cell lineage markers and lymphoid activation markers (EMA and the 115D8 antigen).(ABSTRACT TRUNCATED AT 250 WORDS)

Immunochemical detection of the multidrug resistance-associated protein MRP in human multidrug-resistant tumor cells by monoclonal antibodies

We have generated rat and murine monoclonal antibodies against multidrug resistance-associated protein (MRP), a M(r) 180,000-195,000 membrane glycoprotein involved in a non-P-glycoprotein multidrug resistance of human tumor cells. The antibodies were raised against two different segments of MRP and found to be suitable for protein blot analyses, immunohistochemical and cytochemical studies, as well as flow cytometry of permeabilized cells. The antibodies do not cross-react with the human P-glycoproteins. Immunocytochemistry using MRP-overexpressing tumor cells of different histogenetic origins showed that MRP is predominantly located in the plasma membrane. Immunoelectron microscopy confirmed the plasma membrane location of MRP. The MRP antibodies provide a sensitive and specific tool for studies on MRP-mediated multidrug resistance.

Quantification of biotinylated RNA probes for in situ hybridization using chemiluminescence

For reliable detection of mRNA by non-radioactive in situ hybridization, calibration and standardization of the individual steps involved are essential. We describe a method that allows determination of the size and integrity as well as quantification of biotinylated RNA probes in a single experiment. Serial dilutions of biotinylated RNA probes generated by promoter-mediated in vitro transcription were size-separated by gel electrophoresis in the presence of known amounts of 5'-biotinylated oligomers which served as internal standard. Following immobilization onto nylon membranes and visualization by chemiluminescence, optical densities of probes and internal standards were measured by densitometry and analysed by linear regression. RNA probes complementary to the human homeobox genes HOX-C6, -C8 and -C9 were quantified. Four different 5'-biotinylated oligomers (20, 35, 50 and 75 bases) were tested as internal standards. Concerning the separation of probe and oligomer in the gel, transfer properties and efficiency of binding to the membrane, the oligomer of 35 bases was found to be the best internal standard with highest reproducibility. Comparison of probe concentration by spectrophotometry and the described method showed a good correlation, indicating that our method is a reliable assay for quantitative and qualitative control of biotin-labelled probes.

Persistent augmentation of natural-killer- and T-cell-mediated cytotoxicity in peripheral blood mononuclear cells pulsed in vitro with high-dose recombinant interleukin-2 prior to culturing with a low maintenance dose

The toxicity of high-dose recombinant interleukin-2 (rIL-2) treatment limits its use in tumour therapies. This paper describes in vitro studies of whether a single, peak rIL-2 dose, followed by low maintenance doses, could enhance the cytotoxic potential of peripheral blood mononuclear cells (PBMC) without inducing a significant sustained release of secondary cytokines, known to contribute to undesirable side-effects of therapy. Pre-pulsing of PBMC with high-dose rIL-2 (16,000 IU/ml for 30 min), followed by low-dose (5 IU/ml) maintenance culturing, was found to induce persistent augmentation of cytotoxic activity towards natural-killer(NK)-sensitive and -insensitive tumour targets, as well as increased T-cell-mediated target cell killing. Under these conditions the level of killing was as high as that achieved by higher maintenance doses (20-100 IU/ml). Although not reflected by overexpression of cell surface markers, enhanced activation of cytotoxic capacities by high-dose pre-pulsing remained clearly apparent for at least 12 days of culture. Increased secondary cytokine production (tumour necrosis factor, interleukin-6 and interferon gamma) was only evident during the first 24-72 h after pulsing, and not at later stages of culturing at the low maintenance dose of 5 IU rIL-2/ml. These results may warrant a human phase-1 B study to investigate the in vivo effect of high-dose prepulsing, followed by low-dose maintenance.

Differences in MHC and TAP-1 expression in cervical cancer lymph node metastases as compared with the primary tumours

In previous studies we have shown down-regulation of class I major histocompatibility complex (MHC) expression in a significant proportion of primary cervical carcinomas, which was found to be strongly correlated with loss of expression of the transporter associated with antigen presentation (TAP). By contrast, class II MHC expression was frequently up-regulated on neoplastic keratinocytes in these malignancies. In order to investigate whether these changes are associated with biological behaviour of the tumours, 20 cervical carcinomas were analyzed for MHC (HLA-A, HLA-B/C, HLA-DR) and TAP-1 expression in the primary tumours and in lymph node metastases by immunohistochemistry. The results showed a significant increase in the prevalence of HLA-A and HLA-B/C down-regulation in metastasised neoplastic cells as compared with the primary tumour (P = 0.01). In all cases this was accompanied by loss of TAP-1 expression. Up-regulated HLA-DR expression was found exclusively in primary tumours and was absent in the corresponding metastases (P = 0.002). These data are consistent with the hypothesis that loss of TAP-1 and the consequent down-regulation of class I MHC expression provides a selective advantage for neoplastic cervical cells during metastasis. Furthermore, the lack of class II MHC expression in metastasised cells either reflects a different local lymphokine production or indicates that these cells may have escaped CD4+ cytotoxic T-lymphocyte (CTL)-mediated killing.

Classification of primary cutaneous T-cell lymphomas

The term cutaneous T-cell lymphoma designates a group of neoplasms of skin homing T-cells that show considerable variation in clinical presentation, histological appearances, immunophenotype and prognosis. The disadvantages of currently available histological classification schemes are discussed and a new classification is presented. This is based on a combination of clinical, histological and immunophenotypic criteria and it recognizes distinct clinico-pathological entities within this group of diseases.

[Autopsies for general practitioners and for clinical specialists; analysis of indications]

OBJECTIVE

To evaluate the reasons for autopsies requested by general practitioners, compared with autopsies requested by clinicians.

DESIGN

Retrospective descriptive comparative study.

SETTING

Department of Pathology, Free University Hospital, Amsterdam; Medical Centre Alkmaar; Regional Laboratory Twente, Enschede and Regional Pathology Laboratory, Blaricum.

MATERIAL AND METHOD

In a series of 303 autopsies requested by general practitioners, the reasons for the autopsy were divided into the following categories: sudden unexpected death, short fatal course of disease, intrauterine and perinatal death, evaluation of a protracted course of disease, non-natural death, and others. Results were compared with two series of 2961 and 1747 autopsies performed for clinicians in a university hospital and a non-university hospital, respectively.

RESULTS

General practitioners requested autopsy mainly in cases of sudden unexpected death (48.2%) and short fatal courses of disease (16.5%). For the autopsies requested by clinicians in the university hospital these figures were 6.1% and 15.5%, respectively, in the non-university hospital 9.1% and 18.2%. Owing to the autopsies requested the percentage of cases with unknown or uncertain cause of death was reduced from 67.1% to 14.4%.

CONCLUSIONS

General practitioners mainly request autopsy when important questions of themselves or of the bereaved need to be answered. Thresholds for autopsy, including financial ones, need to be eliminated to enable general practitioners to request autopsies.

Histopathological features and grading in rhabdomyosarcomas of childhood

Rhabdomyosarcoma represents a large group of soft tissue sarcomas displaying heterogeneous histopathological features. In addition to their histopathological classification, the variable expression of a number of histopathological features may contribute to the heterogeneity and may be related to prognosis. Tissue sections of 113 well-documented, protocol-treated patients with long term follow-up (mean 6 years) were analysed by a panel of four paediatric pathologists. The following features were assessed: presence of rhabdomyoblasts, degree of maturation of rhabdomyoblasts, heterogeneous maturation patterns, mitotic activity, tumour necrosis, myxoid component, and septa. A scoring system was allocated to each index. High degree of maturation (amount of cytoplasm greater than surface area of the nucleus), absence of tumour necrosis (< 10% of tumour surface), and absence of septa (< 10% of tumour surface) significantly correlated with a favourable clinical course. Reproducibility in the assessment of these three features was good: mean kappa varying from 0.53 to 0.64. A rhabdomyosarcoma score function for survival was defined by: (-0.27 x degree of maturation score) + (0.007 x percentage septated area) + (0.031 x percentage tumour necrosis). Based on the score a two-grade system was elaborated, i.e. grade I (score < -0.20) v. grade II (score > or = -0.20). Rhabdomyosarcoma grade appeared to be the best factor in predicting patients survival: 69% long-term survival in patients with grade I v. 33% in patients with grade II (P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of cytomorphologically abnormal cervical scrapes for the presence of 27 mucosotropic human papillomavirus genotypes, using polymerase chain reaction

The aim of this study was to investigate the distribution of 27 mucosotropic human papillomavirus (HPV) genotypes (HPV 6, 11, 13, 16, 18, 30, 31, 32, 33, 35, 39, 40, 42, 43, 44, 45, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61 and 66) in cytomorphologically abnormal cervical scrapes (Pap IIIa-Pap IV; n = 1,373) using the polymerase chain reaction (PCR) method on crude cell suspensions. The scrapes were analyzed for the presence of HPV DNA by HPV general-primer-mediated PCR (GP-PCR), which allows the detection of a broad spectrum of HPV types at the subpicogram level. Subsequently, 2 HPV typing procedures based on either type-specific PCR (for HPV 6, 11, 16, 18, 31 and 33) or characterization of GP-PCR products by hybridization (for HPV 13, 30, 32, 35, 39, 40, 43, 44, 45, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61 and 66) were applied. Increasing total HPV prevalence was found with increasing severity of dysplasia from 71% in Pap IIIa to 100% in Pap IV scrapes (carcinoma in situ). The scrapes which were positive by type-specific PCR included 47% cases of Pap IIIa, 71% cases of Pap IIIb and 90% cases of Pap IV. Moreover, 12% of Pap IIIa scrapes, 6% of Pap IIIb scrapes and 8% of Pap IV scrapes revealed positivity for one or more of the remaining HPV types, as determined by successive hybridizations of the GP-PCR products. Taking the typing data together, we noted that the level of HPV heterogeneity decreased from 22 different HPV types (HPV 6, 11, 16, 18, 31, 33, 35, 39, 40, 42, 43, 44, 45, 51, 52, 54, 55, 56, 58, 59, 61 and 66) detected in the group of Pap IIIa scrapes to 13 (HPV 6, 11, 16, 18, 31, 33, 35, 45, 51, 52, 58, 59 and 61) and 10 HPV genotypes (HPV 6, 16, 18, 31, 33, 45, 51, 52, 54 and 58) in the Pap IIIb and Pap IV classes, respectively. An increasing prevalence rate from Pap IIIa to Pap IV was found for HPV 16, 18, 31, 33, 45 and 54. The prevalence rate of identified HPV genotypes increased from 59% in Pap IIIa to 98% in Pap IV, indicating that almost all high-risk HPV genotypes related to cervical cancer in The Netherlands have been characterized.

Sarcomatoid carcinoma of the urinary bladder. Clinicopathologic analysis of 18 cases with immunohistochemical and electron microscopic findings

Sarcomatoid carcinoma is a rare tumor in the urinary bladder and accounts for approximately 0.3% of all bladder malignancies. In this study, the clinicopathologic findings of 18 cases are described. Distribution of sex and age and clinical symptoms are not distinctive from transitional cell carcinoma. The tumor behaves as a high-grade malignancy with advanced initial stage and unfavorable outcome. Surgery is the therapy of choice. Histological differentiation from true sarcoma may be difficult. Recognition rests on the co-existence of an overt carcinomatous component or demonstration of the epithelial nature by immunohistochemistry or electron microscopy.

A new monoclonal antibody (3A5) that recognises a fixative resistant epitope on tissue macrophages and monocytes

AIMS

To develop a monoclonal antibody specific for human macrophages in routinely processed material.

METHODS

The monoclonal antibody was derived from a mouse popliteal lymph node after subcutaneous immunisation in the footpad with fragments of human spleen depleted of lymphocytes and erythrocytes.

RESULTS

3A5 is a monoclonal antibody reactive with macrophages, monocytes, and histiocytes in routinely processed (formalin fixed, paraffin wax embedded) human tissue specimens. Unlike the well known panmacrophage marker KP1 (CD68), neither dendritic cells (interdigitating cells, Langerhans' cells, and microglia) nor myeloid, lymphoid, or epithelial cells stained with 3A5.

CONCLUSION

As the staining pattern of 3A5 is restricted, compared with other macrophage markers and the recognised epitope survives common fixation and embedding procedures, 3A5 is a valuable marker for histiocytes and macrophages in routine diagnostic applications.