Initial free cortisol dynamics following blunt multiple trauma and traumatic brain injury: A clinical study.

OBJECTIVE: To determine free and total cortisol serum concentrations in the first 24 h after trauma and to evaluate the influence of traumatic brain injury (TBI) on their dynamics. METHODS: This prospective cohort study enrolled patients who had experienced multiple trauma and were admitted to a level 1 trauma centre. The patients were divided in two groups based on the presence of TBI according to clinical and radiological findings. Blood was collected initially as well as at 12 h and 24 h after the traumatic injury. Total cortisol, corticosteroid binding globulin (CBG) and free cortisol levels were determined. RESULTS: The study analysed data from 49 patients (36 males and 13 females) with a mean ± SD age of 45.0 ± 16.0 years. Of these, 36 presented with TBI and 13 had multiple injuries without TBI. Patients with TBI showed significantly lower concentrations of total cortisol and free cortisol compared with patients without TBI. Repeated measures analysis revealed different concentration dynamics in patients with TBI, with no increase in cortisol after trauma. CONCLUSION: Multiple trauma patients with TBI are at risk of acute impaired cortisol secretion and show an attenuated stress response as early as 12 h after injury.

An investigation of red blood cell concentrate quality during storage in paediatric-sized polyvinylchloride bags plasticized with alternatives to di-2-ethylhexyl phthalate (DEHP).

BACKGROUND AND OBJECTIVES: Di-2-ethylhexyl phthalate (DEHP) is a blood bag plasticizer. It is also a toxin, raising concerns for vulnerable populations, for example, neonates and infants. Here, the in vitro quality of red cell concentrates (RCC) stored in paediatric bags formulated with alternative plasticizers to DEHP was compared. MATERIALS AND METHODS: RCC were pooled and split into polyvinylchloride (PVC)/DEHP, PVC/1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH) or PVC/butyryl trihexyl citrate (BTHC) bags. Quality was assessed on storage days 5, 21, 35 and 43. RESULTS: Metabolism differed among the bags: pCO2 levels were lowest and pO2 were highest in BTHC bags. Glucose consumption and lactate production suggested higher metabolic rates in BTHC bags. ATP levels were best maintained in DINCH bags (day 43 mean level: 2·86 ± 0·29 µmol/g Hb). RCC in BTHC bags had the greatest potassium release (54·6 ± 3·0 mm on day 43). From day 21, haemolysis was higher in BTHC bags (P < 0·01) and by day 43 had exceeded 0·8% (0·85 ± 0·10%). RCC in BTHC bags showed more microparticle formation than RCC in DEHP or DINCH bags. CONCLUSION: The results suggest that the BTHC formulation used was detrimental to RBC quality. DINCH bags could be a viable alternative to DEHP: they outperformed DEHP bags energetically, with better maintenance of ATP levels.

[Operative treatment of rhizarthrosis with trapezectomy and suspension of the first metacarpal with a Mini TightRope®]. / Die operative Versorgung der therapierefraktären Rhizarthrose mittels Trapezektomie und Suspension des ersten Strahls mittels Mini TightRope®

PURPOSE: The aim of this work was to examine the utility of the Mini TightRope(®) after trapezectomy and suspension of the first metacarpal in cases of clinically manifest rhizarthrosis. PATIENTS AND METHOD: 31 Patients (26 female, 5 male, mean age 57.9 years) with primary rhizarthrosis were treated with a trapezectomy and suspension of the first metacarpal with a Mini TightRope(®) (cost 225 Euro). In the course of a retrospective study, all patients underwent a clinical and radiological re-examination at an average of 13.5 (6-22) months. To assess the therapy, a clinical and radiological examination as well as the score of Buck-Gramcko were used. RESULTS: 74.2% of the patients obtained good and very good results, 12.9% achieved satisfactory or poor outcomes. In 2 patients the Mini Tight-Rope(®) had to be removed due to a proximalisation of the first metacarpal and strong pain in rest and motion after 6-7 months. Whereas the distance between the distal scaphoid pole and the base of the first metacarpal postoperatively averaged 11.1 (8-14) mm, it averaged 5.3 (0-10.2) mm in the follow-up examination. CONCLUSION: With the presented procedure it is possible to achieve in the majority of the treated patients good and very good results. 2 early removals of the implants, a documented proximalisation in spite of the implant and the price of the Mini TightRope(®) of currently 225 Euro need to be discussed critically.

[Reconstruction of a broad infected defect zone of the distal part of the radius by tractionosteogenesis]. / Distraktionsosteogenese (Kallusdistraktion) zur Behandlung eines metaphysären Schussdefektbruches des Radius.

We report about a reconstruction of a broad infected defect zone by tractionosteogenesis and following implantation of a graft from the iliac crest and a plate fixation at the distal part of the radius after a gunshot injury by a high-velocity bullet.

Basal carcinoma of the breast revisited: an old entity with new interpretations.

The introduction of global gene expression analysis in breast cancer research has focused attention onto a repeatedly described subgroup of invasive breast cancer, the basal-like carcinomas. This subgroup is characterised by the expression of high-molecular weight cytokeratins 5, 14 and 17; using immunohistochemical diagnosis, it represents approximately 7-20% of invasive breast cancers. Some of these tumours fulfil the criteria of grade 3 invasive ductal carcinoma, the so-called triple negative carcinomas. However, other rare subgroups of metaplastic, medullary and myoepithelial carcinomas also belong to this entity. Even though the initial clinical prognostic relevance of basal-like breast cancers may have been overestimated, its distinctive biology generates many questions regarding the pathogenesis, chemosensitivity and optimal clinical management of this subgroup. Physiological progenitor cells within the normal female breast share essential immunohistochemical features with basal-like breast cancers. Although the exact relationship between subgroups of normal breast cells and their respective malignant counterparts is still under investigation, the major hallmarks of physiological progenitor cells are either maintained or reactivated by distinct genetic changes in basal breast cancer cells. This review will discuss the impact of these findings on our global understanding of breast cancer pathogenesis, especially from the perspective of its potential histogenesis. Clinical consequences and potential future research directions driven by the definition of basal breast cancers will also be discussed.

Fibre-related nitric oxide synthase (NOS) in Duchenne muscular dystrophy.

Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The loss of NO synthase (NOS) from the sarcolemma was assumed to be associated with development of Duchenne muscular dystrophy (DMD). We have, however, recently reported that, in contrast to the commonly accepted view, NOS expression in DMD myofibres is up-regulated. This poses the question of the fibre type-specific NOS expression in DMD muscles and how the NOS expression is related to the regeneration or degeneration status. To address this issue, we examined localization of NOS isoforms I, II and III in skeletal muscles of DMD patients employing immunohistochemical labelling with tyramide signal amplification complemented with enzyme histochemistry. We found that NOS immunolabelling as well as metabolic enzyme activity in DMD muscles were heterogeneously distributed along the fibre length of DMD muscle fibres revealing regenerating and degenerate (hypercontracted) fibres as well as normal segments. Like in normal muscles, positive NOS immunoreactivity was found to be associated with fast-oxidative glycolytic (FOG) phenotype. The regeneration status of NOS-positive segments was deduced from the presence of neonatal and developmental myosin heavy chains. High NOS expression in regenerating DMD muscle fibres can be well reconciled with reports about the protective role of endogenous NO in inflammatory diseases and in muscle repair.

Implementation of a map in radical prostatectomy specimen allows visual estimation of tumor volume.

INTRODUCTION: Tumor volume is one of the best documented prognostic factors for prostate cancer. There are several methods to gain this important parameter but unfortunately most of the clinicians in the world do not get this information in their routine practice from the pathologist. We developed a standardized method to handle radical prostatectomy specimens including a special form of mapping in order to document relevant morphological data. The aim of this study was to investigate if our model of mapping prostate cancer, which we use in routine practice, may serve for visual estimation of tumor volume. METHODS: We estimated the tumor volume of prostate cancer by visual estimation of 350 maps of radical prostatectomy specimens and correlated these data with established prognostic parameters and clinical outcome. RESULTS: Significant correlations between tumor volumes, as obtained from our mapping, and known prognostic parameters such as preoperative serum levels of prostatic specific antigen, loss of differentiation, histological grade, lymph node metastasis, and margins were found. In a multivariate analysis, only Gleason score and tumor stage were shown to be independent prognostic parameters. DISCUSSION: We demonstrate that mapping of prostate cancer is more than a simple method of documentation but may serve as a method for visual estimation of tumor volume of prostate cancer after radical prostatectomy. This method can further be used for a visual documentation of the tumor stage independent of changes in the TNM classification. The method is inexpensive and practicable and can therefore be applied in routine surgical pathology.

Expression of early placenta insulin-like growth factor in breast cancer cells provides an autocrine loop that predominantly enhances invasiveness and motility.

Early placenta insulin-like growth factor (EPIL) is expressed by a subpopulation of the Her2-positive SKBR3 breast cancer cell line displaying high motility and transendothelial invasiveness in vitro, as recently shown by our group. As a consequence of this, we established cellular models by generating an EPIL-overexpressing SKBR3 cell line, knocked down EPIL by adding specific small interfering RNA (siRNA) to those cells and produced EPIL-enriched and depleted serum-free culture media. EPIL-expressing cells as well as EPIL-induced SKBR3 cells acquired a high capacity for transendothelial invasiveness. We observed a thin and outspread morphology caused by enhanced formation of lamellipodia, i.e. protrusions in the initial phase of motility. In parallel, Her2-positive MDAHer2 breast cancer cells also showed increased invasiveness when induced by EPIL-conditioned medium. A downstream signaling impact of EPIL could be observed in the form of reduced phosphorylation of Her2, erk1/2 and akt, while phospholipase Cgamma1 phophorylation remained unaffected. As an in vivo model for highly motile tumor cells, Paget's disease of the nipple showed simultaneous EPIL and Her2 expression upon immunohistochemical examination using specific antibodies. Such experimental data have been translated to a clinical setting by using a prognostic tissue microarray established from 603 breast cancer cases. Survival data analysis found a significant association between expression levels of EPIL and 5-year overall survival that was dose dependent: EPIL (negative) 84%, EPIL (moderately positive) 77%, EPIL (strongly positive) 48% (P < 0.005). One particular subgroup (7.6% of the cases with full clinical records) that comprised tumors simultaneously expressing EPIL and Her2 represented patients with the poorest 5-year overall survival. The results suggested that EPIL might be a cancer cell-produced growth factor that influences lateral Her2 signaling. Moreover, EPIL may be induced by factors apart from Her2 and may independently provide signaling for cancer invasion and motility.

Cytogenetic differences in breast cancer samples between German and Japanese patients.

BACKGROUND: Japanese and German breast cancer cases differ substantially in the frequency of egfr amplification. AIMS: To unravel further the cytogenetic differences between Japanese and German breast cancer cases. METHODS: Forty one Japanese breast cancer cases were evaluated by means of comparative genomic hybridisation (CGH). The results were compared with the CGH results from 161 German breast cancer cases. RESULTS: The mean number of genetic alterations/case was significantly higher in German premenopausal patients with breast cancer than in their Japanese counterparts. Japanese breast cancer cases revealed a higher number of chromosome 17p losses. Losses of 8p were associated with oestrogen receptor (ER) negativity in Japanese patients with breast cancer, whereas in the German patients gains of 3q and 6q were associated with the lack of ER expression. CONCLUSIONS: The interethnic differences of invasive breast cancer are reflected by cytogenetic aberrations, which are also associated with the differential expression of the ER.

Expression of endothelin-A-receptor predicts unfavourable response to neoadjuvant chemotherapy in locally advanced breast cancer.

Endothelin-1 (ET-1) and its receptors (ETAR and ETBR), referred to as the endothelin (ET) axis, are overexpressed in breast carcinomas and appear to influence tumour growth and progression. The objective of this study was to determine the effect of expression of the ET axis in breast carcinomas on response to cytotoxic chemotherapy. The study included 44 patients with locally advanced breast cancer participating in a prospective phase III study evaluating high-dose neoadjuvant chemotherapy of epirubicin and cyclophosphamide. Expression of ET-1, ETAR and ETBR was determined by semiquantitative immunohistochemical analysis of breast cancer tissue from prechemotherapy tru-cut biopsies. Immunohistochemical staining was positive for ET-1 in 61.5%, for ETAR in 35% and for ETBR in 35.9% of breast carcinomas. Pathological response to chemotherapy was significantly decreased in ETAR-positive patients (P=0.002). In total, 50% of ETAR-positive patients as compared to 7.7% of ETAR-negative patients attained pathologically 'no change'. Logistic regression confirmed ETAR as an independent predictive marker for pathological response (P=0.009). These data indicate that increased expression of ETAR in breast carcinomas is associated with resistance to chemotherapy. Determination of ETAR status may serve as a predictive marker for identifying patients less likely to be responsive to conventional chemotherapy.

Discrepancies in current practice of pathological evaluation of sentinel lymph nodes in breast cancer. Results of a questionnaire based survey by the European Working Group for Breast Screening Pathology.

AIMS: To evaluate aspects of the current practice of sentinel lymph node (SLN) pathology in breast cancer via a questionnaire based survey, to recognise major issues that the European guidelines for mammography screening should address in the next revision. METHODS: A questionnaire was circulated by mail or electronically by the authors in their respective countries. Replies from pathology units dealing with SLN specimens were evaluated further. RESULTS: Of the 382 respondents, 240 European pathology units were dealing with SLN specimens. Sixty per cent of these units carried out intraoperative assessment, most commonly consisting of frozen sections. Most units slice larger SLNs into pieces and only 12% assess these slices on a single haematoxylin and eosin (HE) stained slide. Seventy one per cent of the units routinely use immunohistochemistry in all cases negative by HE. The terms micrometastasis, submicrometastasis, and isolated tumour cells (ITCs) are used in 93%, 22%, and 71% of units, respectively, but have a rather heterogeneous interpretation. Molecular SLN staging was reported by only 10 units (4%). Most institutions have their own guidelines for SLN processing, but some countries also have well recognised national guidelines. CONCLUSIONS: Pathological examination of SLNs throughout Europe varies considerably and is not standardised. The European guidelines should focus on standardising examination. They should recommend techniques that identify metastases > 2 mm as a minimum standard. Uniform reporting of additional findings may also be important, because micrometastases and ITCs may in the future be shown to have clinical relevance.

Consistency of staining and reporting of oestrogen receptor immunocytochemistry within the European Union--an inter-laboratory study.

To assess the variability of oestrogen receptor (ER) testing using immunocytochemistry, centrally stained and unstained slides from breast cancers were circulated to the members of the European Working Group for Breast Screening Pathology, who were asked to report on both slides. The results showed that there was almost complete concordance among readers (kappa=0.95) in ER-negative tumours on the stained slide and excellent concordance among readers (kappa=0.82) on the slides stained in each individual laboratory. Tumours showing strong positivity were reasonably well assessed (kappa=0.57 and 0.4, respectively), but there was less concordance in tumours with moderate and low levels of ER, especially when these were heterogeneous in their staining. Because of the variation, the Working Group recommends that laboratories performing these stains should take part in a external quality assurance scheme for immunocytochemistry, should include a tumour with low ER levels as a weak positive control and should audit the percentage positive tumours in their laboratory against the accepted norms annually. The Quick score method of receptor assessment may also have too many categories for good concordance, and grouping of these into fewer categories may remove some of the variation among laboratories.

Mechanisms of DNA double strand break repair and chromosome aberration formation.

It is widely accepted that unrepaired or misrepaired DNA double strand breaks (DSBs) lead to the formation of chromosome aberrations. DSBs induced in the DNA of higher eukaryotes by endogenous processes or exogenous agents can in principle be repaired either by non-homologous endjoining (NHEJ), or homology directed repair (HDR). The basis on which the selection of the DSB repair pathway is made remains unknown but may depend on the inducing agent, or process. Evaluation of the relative contribution of NHEJ and HDR specifically to the repair of ionizing radiation (IR) induced DSBs is important for our understanding of the mechanisms leading to chromosome aberration formation. Here, we review recent work from our laboratories contributing to this line of inquiry. Analysis of DSB rejoining in irradiated cells using pulsed-field gel electrophoresis reveals a fast component operating with half times of 10-30 min. This component of DSB rejoining is severely compromised in cells with mutations in DNA-PKcs, Ku, DNA ligase IV, or XRCC4, as well as after chemical inhibition of DNA-PK, indicating that it reflects classical NHEJ; we termed this form of DSB rejoining D-NHEJ to signify its dependence on DNA-PK. Although chemical inhibition, or mutation, in any of these factors delays processing, cells ultimately remove the majority of DSBs using an alternative pathway operating with slower kinetics (half time 2-10 h). This alternative, slow pathway of DSB rejoining remains unaffected in mutants deficient in several genes of the RAD52 epistasis group, suggesting that it may not reflect HDR. We proposed that it reflects an alternative form of NHEJ that operates as a backup (B-NHEJ) to the DNA-PK-dependent (D-NHEJ) pathway. Biochemical studies confirm the presence in cell extracts of DNA end joining activities operating in the absence of DNA-PK and indicate the dominant role for D-NHEJ, when active. These observations in aggregate suggest that NHEJ, operating via two complementary pathways, B-NHEJ and D-NHEJ, is the main mechanism through which IR-induced DSBs are removed from the DNA of higher eukaryotes. HDR is considered to either act on a small fraction of IR induced DSBs, or to engage in the repair process at a step after the initial end joining. We propose that high speed D-NHEJ is an evolutionary development in higher eukaryotes orchestrated around the newly evolved DNA-PKcs and pre-existing factors. It achieves within a few minutes restoration of chromosome integrity through an optimized synapsis mechanism operating by a sequence of protein-protein interactions in the context of chromatin and the nuclear matrix. As a consequence D-NHEJ mostly joins the correct DNA ends and suppresses the formation of chromosome aberrations, albeit, without ensuring restoration of DNA sequence around the break. B-NHEJ is likely to be an evolutionarily older pathway with less optimized synapsis mechanisms that rejoins DNA ends with kinetics of several hours. The slow kinetics and suboptimal synapsis mechanisms of B-NHEJ allow more time for exchanges through the joining of incorrect ends and cause the formation of chromosome aberrations in wild type and D-NHEJ mutant cells.

Deciphering a subgroup of breast carcinomas with putative progression of grade during carcinogenesis revealed by comparative genomic hybridisation (CGH) and immunohistochemistry.

Distinct parallel cytogenetic pathways in breast carcinogenesis could be identified in recent years. Nevertheless, it remained unclear as to which tumours may have progressed in grade or which patterns of cytogenetic alteration may define the switch from an in situ towards an invasive lesion. In order to gain more detailed insights into cytogenetic mechanisms of the pathogenesis of breast cancer, the chromosomal imbalances of 206 invasive breast cancer cases were characterised by means of comparative genomic hybridisation (CGH). CGH data were subjected to hierarchical cluster analysis and the results were further compared with immunohistochemical findings on tissue arrays from the same breast cancer cases. The combined analysis of immunohistochemical and cytogenetic data provided evidence that carcinomas with gains of 7p, and to a lesser extent losses of 9q and gains of 5p, are a distinct subgroup within the spectrum of ductal invasive grade 3 breast carcinomas. These aberrations were associated with a high degree of cytogenetic instability (16.6 alterations per case on average), 16q-losses in over 70% of these cases, strong oestrogen receptor expression and absence of strong expression of p53, c-erbB2 and Ck 5. These characteristics provide strong support for the hypothesis that these tumours may develop through stages of well- and perhaps intermediately differentiated breast cancers. Our results therefore underline the existence of several parallel and also stepwise progression pathways towards breast cancer.

Genetic imbalances in benign bone tumors revealed by comparative genomic hybridization.

There have been no reports on choromosomal aberrations of benign bone tumors revealed by comparative genomic hybridization (CGH). CGH analysis of benign tumors may be useful in understanding the mechanism of tumorigenesis with comparisons to malignant tumors. There were 4 tumors (2 enchondromas, one chondromyxoid fibroma, and one osteoid osteoma) and 8 tumor-like conditions (4 aneurysmal bone cysts (ABCs), one eosinophilic granuloma, one fibrous dysplasia, one solitary bone cyst, and one Rosai-Dorfman disease) available for analysis. One of 2 enchondromas and one of 4 ABCs exhibited rapid growth. Six lesions showed chromosomal aberrations, while 6 others did not. The most frequent aberrations were the loss of a whole chromosome-19 in 6 cases, the loss of chromosome-arm 22q in 4 cases, and the loss of chromosome-arm 17p in 3 cases. Gains were seen in 13q21 in 2 cartilaginous tumors and at 12q15-q21 in eosinophilic granulomas. Therefore, in benign bone tumors or tumor-like lesions, chromosomal aberrations are not frequent; however, some clear tendencies of clustering of aberrations can be observed.

Demystified...tissue microarray technology.

Several "high throughput methods" have been introduced into research and routine laboratories during the past decade. Providing a new approach to the analysis of genomic alterations and RNA or protein expression patterns, these new techniques generate a plethora of new data in a relatively short time, and promise to deliver clues to the diagnosis and treatment of human cancer. Along with these revolutionary developments, new tools for the interpretation of these large sets of data became necessary and are now widely available. Tissue microarray (TMA) technology is one of these new tools. It is based on the idea of applying miniaturisation and a high throughput approach to the analysis of intact tissues. The potential and the scientific value of TMAs in modern research have been demonstrated in a logarithmically increasing number of studies. The spectrum for additional applications is widening rapidly, and comprises quality control in histotechnology, longterm tissue banking, and the continuing education of pathologists. This review covers the basic technical aspects of TMA production and discusses the current and potential future applications of TMA technology.

Molecular cytogenetic investigations of synchronous bilateral breast cancer.

BACKGROUND: Bilaterality in breast cancer is a rare event and together with an early onset of disease points towards inheritance of the disease. However, most cases seem to occur sporadically, either in a synchronous or metachronous manner. METHODS: Thirty two invasive carcinomas and one in situ carcinoma from 16 patients with synchronous, bilateral breast cancer were investigated by means of comparative genomic hybridisation (CGH) and polymerase chain reaction based multiplex microsatellite analysis. The results were analysed conventionally and were also subjected to a biomathematical cluster analysis. RESULTS: On average, bilateral breast cancer cases showed a low number of genetic alterations, a low frequency of genetic amplifications, and a high rate of chromosomal 16q losses. A distinct, characteristic genetic alteration associated with bilateral breast disease could not be found. Although two tumour pairs appeared to be related using biomathematical processing for microsatellite analysis, this result was reproduced by CGH data processing in one patient only. CONCLUSIONS: Most synchronous, bilateral breast cancer cases seem to represent independent tumours rather than metastatic events. Nevertheless, the possibility of a specific susceptibility remains.

Pathological work-up of sentinel lymph nodes in breast cancer. Review of current data to be considered for the formulation of guidelines.

Controversies and inconsistencies regarding the pathological work-up of sentinel lymph nodes (SNs) led the European Working Group for Breast Screening Pathology (EWGBSP) to review published data and current evidence that can promote the formulation of European guidelines for the pathological work-up of SNs. After an evaluation of the accuracy of SN biopsy as a staging procedure, the yields of different sectioning methods and the immunohistochemical detection of metastatic cells are reviewed. Currently published data do not allow the significance of micrometastases or isolated tumour cells to be established, but it is suggested that approximately 18% of the cases may be associated with further nodal (non-SN) metastases, i.e. approximately 2% of all patients initially staged by SN biopsy. The methods for the intraoperative and molecular assessment of SNs are also surveyed.

Population-based genetic alterations in Ewing's tumors from Japanese and European Caucasian patients.

BACKGROUND: The incidence of Ewing's tumors (ETs) is lower in Asians or African-Americans than in Caucasians. PATIENTS AND METHODS: Japanese ETs were available for analysis of chromosomal aberrations by comparative genomic hybridization (n = 16) and for expression of chimeric EWS transcripts by reverse-transcriptase polymerase chain reaction (n = 11). These results in Japanese patients were compared with those of 62 ETs in European Caucasian patients registered in the European Intergroup Cooperative Ewing's Sarcoma Study. RESULTS: Japanese patients with ET had lower overall survival (P = 0.0446) and relapse-free survival (P = 0.0371) compared with European Caucasian patients. Ten of 11 Japanese ETs and 31 of 62 European Caucasian ETs had type I (EWS exon 7 to FLI1 exon 6) fusion transcripts. In Japanese ETs, the median numbers of chromosomal aberrations were 2.0 and 6.0 in 11 primary tumors and five relapsed tumors, respectively. In European Caucasian ETs, the median number of changes were 2.5 and 5.0 in 52 primary and 10 relapsed tumors, respectively. Frequent gains were 8q (38%), 8p (31%) and 12q (25%) in Japanese ETs and 8q (52%), 8p (48%) and 12q (19%) in European Caucasian ETs. Frequent losses were 19q (44%), 19p (38%) and 17p (25%) in Japanese ETs and 16q (21%), 19q (18%) and 17p (15%) in European Caucasian ETs. The incidence of losses of 19p (P = 0.0215) and 19q (P = 0.0277) were significantly higher in Japanese ETs than in European Caucasian ETs. An amplification (1p33-p34) was observed in only one Japanese ET. CONCLUSIONS: Japanese patients with ET in this study had a worse prognosis than European Caucasian patients. In molecular genetic analyses, Japanese ETs had a higher frequency of loss of chromosome 19 than European Caucasian ETs. Different genetic aberrations may explain the different incidences and prognoses of ET between Caucasian and Japanese patients.

Tissue microarrays: a new approach for quality control in immunohistochemistry.

AIMS: To improve the interpretation of immunohistochemistry (IHC) staining results the use of a tissue microarray technique was established in a routine setting. METHODS: A tissue microarray was constructed by harvesting 600 microm tissue cores from paraffin wax embedded samples available in a routine pathology department. The punches originating from non-tumorous tissue were placed on host paraffin wax blocks. The microarray contained 12 different tissue samples, with a wide antigen profile and a dimension of 3.5 x 3 mm. One section of the multitissue array was placed as an "internal" positive control on each slide of the patient tissue to undergo identical immunohistochemical procedures. RESULTS: Using the tissue microarray technique as a tool for internal quality control, the interpretation of immunohistochemical staining of more than 20 different antigens in routine IHC was improved. The tissue microarray did not influence the staining results in conventional IHC or in different automated IHC settings. CONCLUSION: The regular use of an institution adapted tissue microarray would be useful for internal positive control in IHC to enable different laboratory demands. Furthermore, this technique improves the evaluation of staining results in IHC.