Characterization of breast carcinomas by two monoclonal antibodies distinguishing myoepithelial from luminal epithelial cells

Two monoclonal antibodies, KA 1 and KA 4, raised against human epidermis, were biochemically and immunologically characterized and were shown to react with specific cytokeratin polypeptides. On frozen sections of human mammary gland, these antibodies distinguish between myoepithelial and luminal epithelial cells. We present evidence that in these cells KA 1 antibody recognized cytokeratin 5 and KA 4 antibody cytokeratin 19. In normal mammary tissue, KA 4 antibody invariably reacted with the epithelial cells lining the lumina of acini, ductules, ducts, and sinus. In contrast, KA 1 antibody decorated only the myoepithelial and basal epithelial cells of acini, ducts, and sinus. In ductules, however, KA 1 also stained the luminal cells. All 73 invasive lobular and ductal carcinomas studied reacted with KA 4 antibody; five of these were also positive, apparently in the same tumor cells, with KA 1. The tumor cells of in situ carcinomas were also stained in a homogeneous pattern with KA 4 antibody; KA 1 antibody reacted only with the surrounding myoepithelium. In epithelial hyperplasias, the proliferating cells were decorated by KA 1 and KA 4 antibodies in a heterogeneous pattern. Other antibodies were used for comparison. The results are discussed with respect to epithelial differentiation and pathogenesis and to the application of such antibodies for immunohistodiagnosis of mammary lesions.

Expression of neural BC200 RNA in human tumours

BC200 RNA is a 200-nucleotide-long non-messenger RNA that is selectively expressed in the primate nervous system, where it has been identified in somatodendritic domains of a subset of neurons. BC200 RNA is not normally expressed in non-neuronal somatic cells; it has been shown, however, to be expressed in germ cells and in cultured immortal cell lines of various non-neural origins. In order to investigate whether the neuron-specific expression of BC200 RNA is also deregulated during tumourigenesis in non-neural human tissues, 80 different tumour specimens, representing 19 different tumour types, were screened for the presence of the RNA. BC200 RNA was expressed in carcinomas of the breast, cervix, oesophagus, lung, ovary, parotid, and tongue, but not in corresponding normal tissues. BC200 RNA was not detectable in bladder, colon, kidney, or liver carcinoma tissues examined in this study. These results demonstrate that BC200 expression is deregulated under certain neoplastic conditions. The expression of BC200 RNA in non-neural tumours may indicate a functional interrelationship with induction and/or progression of such tumours.

Wet autoclave pretreatment for antigen retrieval in diagnostic immunohistochemistry

Interest has recently been shown in adapting the microwave oven heating technique for antigen retrieval to routine diagnostic immunocytochemical practice. Although it has proved effective as a specialist method for individual antigen localization in many laboratories, it has certain drawbacks which have hampered its wider routine application. These include the need to monitor the sections during the microwave treatment to prevent damage or drying, the limited number of sections that can be accommodated in the microwave oven, and the inevitable alteration in nuclear morphology induced by the microwaves. In order to obviate these difficulties, we have modified the wet autoclave method of Shin et al. (Lab Invest 1991; 64: 693-702) as a routine technique for retrieval of a variety of cell surface, cytoplasmic, and nuclear antigens in formalin-fixed and paraffin-embedded tissue. The technique produces even enhancement of several refractory antigens in anatomically different sites and has the potential to handle reliably up to 200 sections at a time without significant damage to the section or to nuclear morphology.

Introducing a single-cell-derived human mesenchymal stem cell line expressing hTERT after lentiviral gene transfer

Human mesenchymal stem cells (hMSCs) can be readily isolated from bone marrow and differentiate into multiple tissues, making them a promising target for future cell and gene therapy applications. The low frequency of hMSCs in bone marrow necessitates their isolation and expansion in vitro prior to clinical use, but due to senescence-associated growth arrest during culture, limited cell numbers can be generated. The lifespan of hMSCs has been extended by ectopic expression of human telomerase reverse transcriptase (hTERT) using retroviral vectors. Since malignant transformation was observed in hMSCs and retroviral vectors cause insertional mutagenesis, we ectopically expressed hTERT using lentiviral gene transfer. Single-cell-derived hMSC clones expressing hTERT did not show malignant transformation in vitro and in vivo after extended culture periods. There were no changes observed in the expression of tumour suppressor genes and karyotype. Cultured hMSCs lack telomerase activity, but it was significantly increased by ectopic expression of hTERT. HTERT expression prevented hMSC senescence and the cells showed significantly higher and unlimited proliferation capacity. Even after an extended culture period, hMSCs expressing hTERT preserved their stem cells character as shown by osteogenic, adipogenic and chon-drogenic differentiation. In summary, extending the lifespan of human mesenchymal stem cells by ectopic expression of hTERT using lentiviral gene transfer may be an attractive and safe way to generate appropriate cell numbers for cell and gene therapy applications.

Chromosomal aberrations associated with invasion in papillary superficial bladder cancer

Non-invasive and invasive papillary transitional cell carcinomas of stages pTa and pT1 represent the first steps of tumour progression in bladder cancer. In order to analyse different chromosomal alterations of pTa and pT1 superficial bladder cancer, 46 tumour specimens were examined by comparative genomic hybridization (CGH). Losses of chromosome 9 material (11/20) and gains of chromosome 17 material (6/20) were frequently found in pTa tumours. Stage pT1 tumours were characterized by gains of chromosome 1q (14/26; including amplification at 1q21-q24 in three cases) and chromosome 17 material (15/26), as well as by losses of 11p (15/26) and 11q (13/26). Other loci frequently showing losses in pT1 tumours were 2q (9/26), 4q (10/26), 5q (9/26), 8p (10/26), 9p (9/26), 9q (12/26), 10q (8/26), 17p (7/26), and 18q (8/26). Amplifications were detected at 8q21/22, 5q21, 7q36, 10p14, 10p12, 10q25, 12q12, and 12q14. The most striking differences between grade 2 pTa and pT1 tumours were gains of 1q (P < 0.01) and losses at 2q (P < 0.025), 10q (P < 0.05), 11p (P < 0.01), 11q (P < 0.01), and 17p (P < 0.05), as well as the total number of aberrations (pTa grade 2: 4.1; pT1 grade 2: 8.6 aberrations per tumour). These data show characteristic chromosomal aberrations associated with invasion in superficial bladder cancer.

Prognostic factors in medullary thyroid carcinomas. Survival in relation to age, sex, stage, histology, immunocytochemistry, and DNA content

Patients with medullary thyroid carcinomas (MTC) were analyzed according to age, sex, and tumor stage. In addition, the MTC were screened for the predominant histologic pattern, immunocytochemical spectrum (60 tumors), and DNA content (DNA cytophotometry and DNA flow cytometry, 25 tumors). These findings were correlated with follow-up data available for 45 of these patients. Forty-eight percent of the tumors revealed a polygonal cell pattern, whereas 22% showed spindle-cell predominance. All tumors contained cytokeratin, chromogranin A, and calcitonin (CT). Calcitonin gene-related peptide (CGRP) was present in 92%, carcinoembryonic antigen (CEA) in 77%, neuron-specific enolase (NSE) in 75%, and vimentin in 53% of cases. Positivity for neurotensin, somatostatin, neurofilaments, bombesin, and alpha human chorionic gonadotropin (a-hCG) and serotonin ranged between 3% and 27%. All MTC were negative for substance P, adrenocorticotropic hormone (ACTH), thyroglobulin (TG), or S-100 protein. Local recurrences and regional lymph node metastases revealed identical staining patterns as the primaries. Prognosis of MTC was found not to be related to histologic features (dominant architectural pattern, cellular shape, presence of amyloid deposits) or immunocytochemical pattern. Instead, survival was significantly correlated to age, sex, and stage of disease. The best prognosis was seen in women younger than 40 years and revealing an early stage of disease. DNA measurements added valuable information in assessing the prognosis of MTC.

Inability of Older Adult Patients with Hip Fracture to Maintain Postoperative Weight-Bearing Restrictions

BACKGROUND

For elderly trauma patients, a basic goal is early mobilization, as immobilization can trigger various complications, such as venous thromboembolism, pneumonia, urinary tract infections, and pressure ulcers. Although partial weight-bearing has been shown to significantly increase mortality compared with unrestricted weight-bearing, it remains a frequent recommendation of aftercare following lower-extremity fracture fixation.

METHODS

An insole force sensor was used to measure true postoperative weight-bearing by patients ≥75 years of age treated for hip fracture compared with patients 18 to 40 years of age treated for ankle fracture. Both groups were instructed to maintain partial weight-bearing on the affected limb (≤20 kg) postoperatively. Following standardized physiotherapy training, gait analysis was performed.

RESULTS

None of the patients in the elderly test group were able to comply with the weight-bearing restriction as recommended. We found that 69% (11 of 16) of the patients exceeded the specified load by more than twofold, whereas significantly more patients in the younger control group (>75% [14 of 18]) achieved almost the entire weight-bearing restriction (p < 0.001). Only 1 of the elderly patients was able to comply with the predetermined weight-bearing restriction, and only for a short period of time. In comparison, significantly more patients in the control group (89% [16 of 18]; p < 0.001) maintained the partial load for nearly the entire time during gait analysis.

CONCLUSIONS

Elderly patients seem to be unable to maintain weight-bearing restrictions. As early mobilization of geriatric trauma patients is an important element for a successful rehabilitation, the directive of postoperative partial weight-bearing for these patients should be abandoned.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Immunohistochemically detectable bcl-2 expression in colorectal carcinoma: correlation with tumour stage and patient survival

The bcl-2 gene encodes for a mitochondrial membrane proto-oncoprotein, the expression of which is known to suppress programmed cell death (apoptosis). In the present study the prognostic value of bcl-2 proto-oncoprotein was immunohistochemically investigated in a series of 104 colorectal carcinomas. The bcl-2 staining patterns were semiquantitatively assessed and correlated with the pTNM stage, Dukes' classification, lymphocytic infiltration (Jass classification) and tumour grade as well as parameters not associated with prognosis (gender, age, tumour site, histological tumour type). Statistical analysis was carried out using the Kaplan-Meier method, the log-rank test, hazard ratios and their confidence intervals. Fifty-five out of 104 cases completely lacked immunohistochemical bcl-2 expression. Fewer than 5% of bcl-2-positive cells were found in 25, 5-50% in 17 and more than 50% in five cases. The extent of bcl-2 expression by tumour cells decreased significantly with respect to increasing tumour size (P < 0.05), decreasing lymphocytic infiltration (P < 0.05) and chance of poor clinical outcome (P < 0.05), but not with worsening of Dukes stages. In multivariate analysis (Cox regression model) bcl-2 expression remained as an independent prognostic parameter with Dukes' classification as stratification factor (P < 0.001). Although the biological functions of bcl-2 protein are not yet well understood, our results provide further evidence that bcl-2 oncoprotein appears to be associated with favourable clinical outcome. Thus immunohistochemical bcl-2 phenotyping of colorectal carcinoma may contribute in future to the clinical management of these patients.

Vascular incorporation of endothelial colony-forming cells is essential for functional recovery of murine ischemic tissue following cell therapy

OBJECTIVE

Cord blood-derived human endothelial colony-forming cells (ECFCs) bear a high proliferative capacity and potently enhance tissue neovascularization in vivo. Here, we investigated whether the leading mechanism for the functional improvement relates to their physical vascular incorporation or perivascular paracrine effects and whether the effects can be further enhanced by dual-cell-based therapy, including mesenchymal stem cells (MSCs).

METHODS AND RESULTS

ECFCs or MSCs were lentivirally transduced with thymidine kinase suicide gene driven by the endothelial-specific vascular endothelial growth factor 2 (kinase insert domain receptor) promoter and evaluated in a hindlimb ischemia model. ECFCs and MSCs enhanced neovascularization after ischemic events to a similar extent. Dual therapy using ECFCs and MSCs further enhanced neovascularization. Mechanistically, 3 weeks after induction of ischemia followed by cell therapy, ganciclovir-mediated elimination of kinase insert domain receptor(+) cells completely reversed the therapeutic effect of ECFCs but not that of MSCs. Histological analysis revealed that ganciclovir effectively eliminated ECFCs incorporated into the vasculature.

CONCLUSIONS

Endothelial-specific suicide gene technology demonstrates distinct mechanisms for ECFCs and MSCs, with complete abolishment of ECFC-mediated effects, whereas MSC-mediated effects remained unaffected. These data strengthen the notion that a dual-cell-based therapy represents a promising approach for vascular regeneration of ischemic tissue.

Dendritic/Langerhans cells and prognosis in patients with papillary thyroid carcinomas. Immunocytochemical study of 106 thyroid neoplasms correlated to follow-up data

Paraffin sections of 106 primary thyroid carcinomas were the subject of an immunocytochemical study to determine the density of infiltrates of S-100 protein-positive dendritic/Langerhans cells (LC), lysozyme-positive histiocytes, and LCA-positive lymphocytes. Evidence of dense infiltrates of LCs was found only in the majority of papillary thyroid carcinomas (PCs). The determination of the quantity of LCs proved to be a highly effective means of assessing the prognosis of these tumors. Irrespective of other morphologic and clinical features, no single instance of death resulting from cancer occurred among 23 PCs with dense LC infiltrates (including 6 tumors of stage pT4), while 9 of 53 (17%) of the remaining patients ultimately died from thyroid cancer. On the other hand, the degree of histiocytic and lymphocytic infiltrations was not associated with a distinct biologic behavior neither among PC nor among the remaining thyroid carcinomas. These findings suggest that LCs may play an important role in the immunologic defense mechanisms of the host against the tumor only in the papillary type of thyroid cancer.

Genetic relation of lobular carcinoma in situ, ductal carcinoma in situ, and associated invasive carcinoma of the breast

AIMS

The mutual relation of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) of the breast, as accepted precursor lesions of invasive breast cancer, is controversial. Because they display genetic heterogeneity, it is not clear how genetically advanced these entities are and what causes the transition to an invasive carcinoma.

METHODS

Six cases of LCIS, four of them with associated lobular invasive carcinoma, four cases of intermediately differentiated DCIS with an associated invasive lobular carcinoma, and nine cases of intermediately and poorly differentiated DCIS with associated ductal invasive carcinoma were investigated by means of comparative genomic hybridisation (CGH) after microdissection and immunohistochemical staining of E-cadherin.

RESULTS

LCIS was characterised by a low average rate of copy number changes, no evidence of amplifications, and a high rate of gains and losses of chromosomal material at 1q and 16q, respectively. A high degree of genetic homology with well differentiated DCIS was obvious, as reported previously. The cases of intermediately differentiated DCIS with associated lobular invasive components and lobular differentiation revealed striking homologies, and a significant difference of E-cadherin expression. The comparison of preinvasive and invasive breast lesions, irrespective of differentiation within the same patient, revealed no specific alteration that might be associated with invasion. Genetic alterations seen in invasive carcinoma were not necessarily seen in the adjacent precursor lesions.

CONCLUSIONS

These results provide strong evidence that invasive breast cancer is a disease with multiple cytogenetic subclones already present in preinvasive lesions. Moreover, specific CGH alterations associated with invasion were not observed. Furthermore, the close genetic association between well differentiated and a subgroup of intermediately differentiated DCIS and LCIS led to the hypothesis that LCIS and a subgroup of DCIS are different phenotypic forms of a common genotype.

Tumors of the papilla of Vater--inadequate diagnostic impact of endoscopic forceps biopsies taken prior to and following sphincterotomy

BACKGROUND

It has been proposed that adenomas of the papilla of Vater are precursors of adenocarcinomas. Duodenoscopy with ERCP and forceps biopsies have substantially improved the morphologic exploration of the major duodenal papilla. Yet there is little and contradictory information as to the diagnostic accuracy of endoscopic biopsies in tumors of the papilla. Moreover, after endoscopic sphincterotomy data on the diagnostic impact of endoscopic biopsies from the papilla are scarce and, in most cases, retrospectively obtained. Thus, the aim of the present prospective and histopathologically controlled study was to assess the diagnostic accuracy of endoscopic biopsies taken from tumors of the papilla before and after sphincterotomy.

PATIENTS AND METHODS

Forty patients with tumors of the papilla of Vater were included in the study. In each case, a comparison was made between endoscopic forceps biopsy diagnoses prior to and following sphincterotomy and the definitive histological diagnosis after surgical tumor resection.

RESULTS

Resected tumors were diagnosed histomorphologically as follows: 19 adenocarcinomas (47%), 6 tubular adenomas (15%), 7 villous adenomas (17%), 7 inflammatory non-neoplastic lesions (pseudotumors) (17%), and one adenomyoma (2%). Overall accuracy for preoperative histopathological diagnosis was 62% (25 of 40, 95% CI: 47%-76%) prior to sphincterotomy while it was 70% (28 of 40, 95% CI: 55%-81%) following the procedure. Regarding adenocarcinomas, sensitivity was found to be 21% (4 of 19, 95% CI: 8%-43%) prior to and 37% (7 of 19, 95% CI: 19%-58%) after sphincterotomy while specificity was 100% at both times.

CONCLUSIONS

Endoscopic forceps biopsies do not allow for reliable preoperative diagnosis of tumors of the papilla of Vater.

An immunohistochemical study of the breast using antibodies to basal and luminal keratins, alpha-smooth muscle actin, vimentin, collagen IV and laminin. Part II: Epitheliosis and ductal carcinoma in situ

A detailed immunohistochemical study has been carried out on 63 breast lesions with epitheliosis, ductal carcinoma in situ and clinging carcinoma (lobular cancerization), using antibodies directed against keratins 5/14 and 14, 15, 16, 18, 19, vimentin, smooth muscle actin, collagen IV and laminin. The results have shown that epitheliosis on the one hand and ductal in situ and clinging carcinoma on the other are immunohistochemically different epithelial lesions. Epitheliosis appears to be epithelial hyperplasia with keratin 5/14 and keratin 14, 15, 16, 18, 19-positive cells. Compared to epitheliotic cells tumor cells of clinging carcinoma, lobular cancerization and ductal carcinoma in situ expressed only luminal keratins 14, 15, 16, 18, 19 in 85% of the cases studied; whereas in 15% there was a basal keratin expression. From our results we conclude that the clinging carcinoma (lobular cancerization) represents the initial morphological step in the development of ductal carcinoma in situ and thus may be interpreted as a minimal ductal neoplasia. With the immunohistochemical demonstration of basal and luminal keratins it may be possible in individual cases to differentiate between benign and malignant in situ lesions of the breast.

Immunohistochemically demonstrated metallothionein expression in malignant melanoma

Metallothioneins are ubiquitous proteins with a high affinity for heavy metal ions, e.g. zinc, copper and cadmium. Experimentally, metallothionein over-expression in cell lines derived from a variety of cancers has been associated with resistance to anticancer drugs and irradiation therapy. Using a monoclonal antibody (E9) to metallothionein we investigated immunoreactive expression in routinely fixed and paraffin-embedded tissue from 63 cases of malignant melanoma and 13 secondary deposits. Whereas a variety of cells in normal skin showed metallothionein expression, all forms of benign naevi studied were uniformly negative. In contrast 13/30 'thin' (< or = 1.5 mm; 0.7 +/- 0.4), 25/29 'thick' malignant melanoma (> 1.5 mm; 5.5 +/- 3.9) and 12/13 metastases were positive. Six patients with thin and 19 with thick melanoma with metallothionein expression died during a mean observation period of 6.4 +/- 1.8 and 3.6 +/- 2.5 years, respectively, their survival distribution function analyses giving statistically significant results for both the vertical tumour thickness (P < 0.0001) and metallothionein expression (P < 0.0001). These immunohistochemical results, based on routinely processed paraffin-embedded tissue, suggest that metallothionein expression in malignant melanoma is significantly associated with progressive disease and might therefore be a useful prognostic indicator.

An immunohistochemical study of the breast using antibodies to basal and luminal keratins, alpha-smooth muscle actin, vimentin, collagen IV and laminin. Part I: Normal breast and benign proliferative lesions

The distribution of simple epithelial (K8/18/19) and basal (myoepithelial) (K5/14) keratins, alpha-smooth-muscle actin, vimentin, collagen IV and laminin in normal mammary glands and in benign proliferative lesions was studied using monoclonal antibodies (mAbs). These antibodies (Abs) identified myoepithelial cells and luminal cells specifically. In lesions with adenosis and papillomas, the two-layered formation resembled that of normal glands with a purely myoepithelial-epithelial differentiation. In scleradenotic lesions, the main cell was of myoepithelial immunophenotype with intermixed trabecular-tubular proliferations of simple-type epithelium. The sclerosis seems to be the result of an irregular basal lamina synthesis by the myoepithelial cells. In contrast to these lesions, epitheliosis represents a purely intraluminal cell proliferation of clearly simple epithelial immunophenotype and of cells with a basal keratin phenotype, lacking myoepithelial differentiation antigen actin. The basal keratin type epithelium may represent post-stem or intermediate cells developing into luminal epithelium. Epitheliosis appears to be a purely epithelial hyperplasia with striking similarity to the regeneration of normal breast epithelium. The different proliferative patterns may give an explanation for differences in potential cancer risks of patients with these lesions.

Prognostic value of histobiological factors (malignancy grading and AgNOR content) assessed at the invasive tumour front of oral squamous cell carcinomas

Tumour cells at the invasive front of carcinomas have been found to differ substantially from the rest of tumour cells in a variety of human cancers. The present multivariate survival analysis of 94 oral squamous cell carcinomas (OSCCs) revealed that both the argyrophilic nucleolar organizer regions-associated protein (AgNOR) content of invading tumour cells and a multiparametric histopathological tumour front grade were significantly and independently associated with tumour-related death, irrespective of conventional Broders' grade and clinical stage of the tumours. High tumour front scores and AgNOR content at the invasive OSCC front thus seem to reflect increased malignant potential. Proliferative activity, assessed by standardized AgNOR analysis, most probably represents one of the biological features underlying the usefulness of evaluating the invasive tumour front.

The encapsulated papillary carcinoma of the thyroid. A morphologic subtype of the papillary thyroid carcinoma

Of a total of 182 papillary neoplasms, 25 lesions (average size, 3.1 cm) were classified on cytologic and histologic grounds as being encapsulated carcinomas. In eight of these tumors (32.2%) cervical lymph node metastasis and/or intraglandular lymphatic spread was observed. It was not possible to separate on histologic grounds those that did metastasize from those that did not. The excellent prognosis for the encapsulated variant of papillary thyroid carcinoma was confirmed by a long follow-up period in which no evidence of recurrences or further metastasis was registered as compared with the time of initial diagnosis, whatever the mode of therapy. On the basis of these findings, the encapsulated papillary carcinoma can be regarded as an early or slowly growing form of the papillary thyroid carcinoma.

Nonviral genetic modification mediates effective transgene expression and functional RNA interference in human mesenchymal stem cells

BACKGROUND

Human mesenchymal stem cells (hMSC) are increasingly the focus of both basic and clinical research due to their ability to strike a balance between self-renewal and commitment to mesodermal differentiation. However, the promising therapeutic utility of hMSC in regenerative medical approaches requires detailed knowledge about their molecular characteristics. Therefore, genetic modification of hMSC provides a powerful tool to understand their complex molecular regulation mechanisms.

METHODS

Here we describe a proof of concept approach of separate and combined gene transfer and gene silencing by nonviral DNA transfection of enhanced green fluorescent protein (EGFP) and EGFP-targeted small interfering RNAs (siRNAs) in hMSC. For optimization of nonviral DNA and siRNA transfer different liposomal-based transfection strategies were validated.

RESULTS

The highest fraction of EGFP-expressing hMSC was obtained using Lipofectamine 2000 (50%) which also mediated the highest transfection rates of siRNAs into hMSC (>or=92%). Stably EGFP-expressing hMSC maintained their proliferation capacity paired with the ability to differentiate into different mesodermal lineages (bone, cartilage, and fat) without loss of transgene expression. Based on our nonviral nucleic acid delivery technique we showed efficient, functional, and long-term RNA interference (RNAi) in hMSC by gene specific knock-down of transiently and stably expressed EGFP (88-98%).

CONCLUSIONS

This is the first demonstration of efficient nonviral transfer of both nucleic acids (DNA and siRNA) into hMSC, exhibiting the potential of targeted modification of hMSC. In particular, the combination of these techniques represents a powerful gene transfer/silencing strategy, thus facilitating detailed genetic approaches to study regulatory networks in stem cell differentiation processes.

Analysis of mutant P53 protein in osteosarcomas and other malignant and benign lesions of bone

Alterations of tumour suppressor genes are considered crucial steps in the development of human cancers. Expressions of p53 protein, a product of the tumour suppressor gene altered most commonly in human cancers examined so far, were investigated immunohistochemically in 18 osteosarcomas and 40 other malignant and benign lesions of bone. A monoclonal antibody clone PAb240, which recognizes a common conformational epitope of mutant p53 proteins, stained nuclei of tumour cells in 12 of 18 osteosarcomas (67%). Six tumours (33%) particularly showed positive immunoreactions in more than half of the tumour cells. PAb240 also stained tumour cells in a small number of other malignant bone tumours, such as malignant fibrous histiocytoma, chondrosarcoma, and Ewing's sarcomas. Furthermore, a small number of cells of giant-cell tumours were positively stained. In contrast, PAb240 was completely negative in 21 benign bone tumours and reactive lesions examined. Another monoclonal antibody clone PAb1801, which reacts with both wild- and mutant-type p53 protein, reacted in nuclei of tumour cells of 7 osteosarcomas (39%). Most of those also reacted with PAb240. PAb1801 was expressed much more frequently in other malignant bone tumours and giant-cell tumours. In addition, PAb1801 showed intranuclear positive reactions in tumour cells of a benign chondroblastoma, and reactive cells such as actively proliferating preosteoblasts in a myositis ossificans and osteoclast-like giant cells in a giant-cell tumour. The immunoelectron-microscopic observation that p53 protein was localized in euchromatic areas of nuclei of osteosarcoma cells supported the specificity of immunoreaction for p53 protein, indicating an active role of p53 protein in the regulation of DNA synthesis and transcription. These findings suggest that point mutation of the p53 gene is frequently involved in the development of osteosarcomas. PAb240 may be a useful tool not only in screening point mutations of the p53 gene in osteosarcomas but also in the differential diagnosis between osteosarcomas and reactive bone-forming lesions. Expressions of mutant p53 protein were not correlated with any clinical or pathological factors examined, although the results should be confirmed in studies of a large number of osteosarcomas.

Complications of locked plating for proximal humeral fractures-are we getting any better?

BACKGROUND

Complication rates reported after locking plate fixation of proximal humeral fractures still range up to 40%. Whether modifications of surgical techniques, use of primary shoulder arthroplasty, or a fracture-specific management resulted in decreased complication rates during recent years remains unclear. Therefore, the aim of this long-term observation study was to analyze the incidence of complications and revision surgery after locked plating.

METHODS

Between February 2002 and December 2013, 788 patients (aged 67.4 ± 17.3 years) with displaced proximal humeral fractures were treated with locking plate, primary hemiarthroplasty (HA), or reverse shoulder arthroplasty (RSA). Standardized follow-up included radiographs at 1 day, 6 weeks, and 3, 6, and 12 months. Complications and unplanned revision surgery were prospectively recorded over the complete follow-up.

RESULTS

Of 788 patients, 646 (82%) were treated with locking plate, 82 (10.4%) with HA, and 60 (7.6%) with RSA. Mean follow-up was 14.8 ± 3.8 months. The mean complication rate associated with locked plating was 12.8%, and revision surgery was necessary in 11.6%. Within the last 5 years, the loss of fixation rate markedly decreased from 14.3% to 4.8%; simultaneously, an increased use of RSA was observed.

CONCLUSION

The overall complication rate of locking plate osteosynthesis for proximal humeral fractures has been decreasing considerably within the last years. Among others, this might be due to an increased use of primary RSA for complex fracture types. In addition to a precise surgical technique, choosing the adequate treatment for each individual fracture to avoid complications and revision surgery is of utmost importance.

First inducible transgene expression in porcine large animal models

The purpose of this study was to establish inducible transgene expression in pigs, a model organism with great promise for experimental physiology and translational medicine, using the binary tet-on system. This expression system is activated by doxycycline (dox) via the tet-controlled transactivator (TA). Binding of TA to the transactivator response element (TRE) results in transcription of downstream genes. First, we cloned transgenic founder pigs expressing TA under the control of the CMV enhancer/chicken β-actin promoter (CAG). Then, cells from CAG-TA transgenic founders were nucleofected with TRE-controlled expression vectors for either porcine cytotoxic T-lymphocyte associated antigen 4-Fc domain of immunoglobulin G1 (CTLA-4Ig) or soluble receptor activator of NF-κB ligand (RANKL), and double-transgenic offspring were cloned. Dox administration resulted in a dose-dependent increase in expression of CTLA-4Ig or RANKL, in nucleofected cells and in transgenic pigs, while in the absence of dox, the levels of both proteins were below the detection limit. Inducible transgene expression was reproduced in double-transgenic offspring generated by cloning or breeding. Our strategy revealed the first two examples of inducible transgene expression in pigs. The CAG-TA transgenic pigs generated in this study constitute an interesting basis for future pig models with inducible transgene expression.

Interdisciplinary consensus on the use and technique of vacuum-assisted stereotactic breast biopsy

PURPOSE

Quality assurance of stereotactic vacuum-assisted breast biopsy (VB).

METHOD

A consensus was achieved based on the existing literature and the experience of VB users (Ethicon Endosurgery, Norderstedt).

RESULTS

The imaging work-up must be completed according to existing standards before an indication for stereotactic VB is established. Indications include microcalcifications and small non-palpable masses; for the time being lesions very close to the skin and architectural distortions (radial scar) are considered less suitable. Acquisition of >20 cores (11 Gauge) should be routinely attempted (goals: as complete a removal of small lesions as possible, thereby increasing diagnostic confidence and reducing so-called 'underestimates'). The pre/post-fire and post-biopsy stereotactic images and a post-biopsy orthogonal mammogram must be documented. All cases with no or uncertain histopathological correlation require discussion in a regular interdisciplinary conference and a documented consensus concerning further work-up or therapy. Standardised documentation of the primary findings and follow-up mammography after approximately 6 months is requested.

CONCLUSION

This consensus includes protocols for the establishment of an indication, performance indicators, interdisciplinary interpretation and therapeutic recommendation, documentation and follow-up. It does not replace official recommendations for percutaneous biopsy.

Gains and losses of CD44 expression during breast carcinogenesis and tumour progression

AIMS

This study was performed to investigate whether the CD44 immunophenotype of breast lesions correlates with the clinical evolution and prognosis of breast cancer.

METHODS AND RESULTS

One-hundred and fifty-two routinely processed normal, benign and malignant breast tissue samples were investigated by the following monoclonal antibodies: CD44s (F10-44-2), CD44v3 (3G5), CD44v4 (11.10), CD44v5 (VFF-8), CD44v6 (VFF-18), CD44v7 (VFF-9), CD44v9 (11-24) after wet autoclave pretreatment for antigen retrieval. We found that: (1) in normal breast tissues luminal epithelial cells lacked detectable CD44 in contrast to basal cells, which constitutionally expressed CD44s, v3, v5 v6 and v9 isoforms; (2) in the intraductal compartment of benign hyperplastic lesions, there was scattered or focal staining for CD44s, v5, v6, v7 and v9 isoforms; (3) in neoplastic lesions restricted neo-expression of CD44v3 and v4 was detected; and (4) the CD44 immunophenotype of invasive breast carcinomas was influenced largely by differentiation grade, steroid receptor status of the tumours and significantly correlated with metastatic involvement of the axillary lymph nodes.

CONCLUSIONS

Qualitative and quantitative changes of CD44 expression are implicated in early stages of breast carcinogenesis. The restricted neo-expression of certain CD44 isoforms in breast neoplasias suggests that CD44 might be a potential target for future antibody-based tumour therapy.

Immunohistochemical distribution of chromogranins A and B and secretogranin II in neuroendocrine tumours of the gastrointestinal tract

The aim of the present study was to investigate immunohistochemically the distribution of chromogranin A, chromogranin B, and secretogranin II in a series of 152 neuroendocrine tumours of the gastrointestinal tract. Tumour tissues from 25 argyrophil gastric carcinoids, 18 gastrin and 5 somatostatin-producing tumours, 4 'gangliocytic paragangliomas', 49 classical argentaffin and 2 L cell appendiceal carcinoids, 27 classical ileal carcinoids, 17 rectal carcinoids, and 5 poorly differentiated neuroendocrine tumours of the stomach and rectum were immunostained with antibodies against chromogranin A, chromogranin B, and secretogranin II. Chromogranin A was the major granin expressed in gastric carcinoids and in serotonin-producing carcinoids of the appendix and the ileum. In contrast, strong chromogranin B and secretogranin II immunoreactivity was found in rectal carcinoids, in which chromogranin A was rarely expressed. Since chromogranin A is a widely used marker for neuroendocrine differentiation, it is of diagnostic importance that some gastrin-producing tumours, 'gangliocytic paragangliomas', poorly differentiated neuroendocrine carcinomas, and appendiceal L cell carcinoids completely lacked chromogranin A positivity. It is concluded that the various neuroendocrine tumours of the gastrointestinal tract show distinctly different patterns of granin expression, probably reflecting their histogenetical origin.