POS1559-HPR PHYSIOTHERAPISTS MAKE LIMITED USE OF BEHAVIOUR CHANGE TECHNIQUES DURING PHYSICAL ACTIVITY COUNSELLING FOR PEOPLE WITH AXIAL SPONDYLOARTHRITIS

Background

The 2018 EULAR recommendations for physical activity (PA) in people with inflammatory arthritis and osteoarthritis state that PA in generally recommended dose is effective, safe and feasible (1). Based on the recommendations, the Ankylosing Spondylitis Association of Switzerland (SVMB) developed a concept for their exercise groups, consisting of guidance on exercising, regular fitness assessments and individual PA counselling by the group-leading physical therapist (PT). The use of behaviour change techniques (BCTs) during PA counselling ought to support counselees’ adherence to individual, unsupervised exercising.

Objectives

To assess the BCTs used by the PTs during their PA counselling sessions with the members of their axSpA exercise groups.

Methods

An observational cross-sectional study was performed with the first cohort of PTs (n=16) who applied the new concept and provided PA counselling, and their group members who agreed to participate. All first counselling sessions with an individual with axSpA were audiotaped, transcribed and analysed using a coding manual for BCTs (2). The manual includes 38 BCTs across the determinants ‘knowledge’ (2 BCTs), ‘awareness’ (8 BCTs), ‘social influence’ (3 BCTs), ‘attitude’ (4 BCTs)’, ‘self-efficacy’ (6 BCTs), ‘intention (6 BCTs)’, ‘action control’ (2 BCTs), ‘facilitation’ (2 BCTs), ‘maintenance’ (5 BCTs). Two raters familiar with BCTs identified the BCTs used by the PTs. They repeatedly discussed and agreed about their classifications of PTs’ phrasings to BCTs in an iterative process to achieve consistency over all counselling sessions. A BCT could be used several times within one counselling session.

Results

A total of 12 PTs (75%) who counselled 41 people with axSpA participated. All 41 PA counselling sessions, lasting between 30-55 minutes were analysed. Overall, 15 out of the 38 BCTs were identified. Across each determinant (with its number of BCTs), the most and least frequently used BCTs were as follows: 1) determinant ‘knowledge’ (1 of 2 BCTs used): ‘provide general information’ (469 times by 12 PTs); 2) ‘awareness’ (3 of 8 BCTs used): reflective listening and ‘self-monitoring of behaviour’ (328x by 12 PTs and 39x by 9 PTs respectively); 3) ‘social influence’: none of 3 BCTs used; 4) ‘attitude’ (1 of 4 BCTs used): persuasive communication (184x by 11 PTs); 5) ‘self-efficacy’ (3 of 6 BCTs used): verbal persuasion and guided practice (77x by 11 PTs and 3x by 3 PTs respectively); 6) ‘intention’ (4 of 6 BCTs used): general intention formation and develop training schedule (250x by 12 PTs and 18x by 5 PTs respectively); 7) ‘action control’ (1 of 2 BCTs used): use of cues (199x by 12 PTs), 8) ‘facilitation’: none (of 2) BCTs used; 9) ‘maintenance’ (2 of 5 BCTs used): continuous professional support and individualize regimen (137x by 12 PTs and 70x by 10 PTs respectively).

Conclusion

The study identified that PTs used only a limited number of BCTs. BCTs considered less effective such as providing information were widely used, whereas BCTs that are considered effective, such as specific aims or coping with barriers were much less or not at all used. This study provides an insight in real clinical practice and may help to develop counselling training for PTs. There is a need to translate theoretical BCTs into effective measures that are easy to use in clinical practice.

References

[1]Rausch Osthoff A-K et al. 2018 EULAR recommendations for physical activity. Ann Rheum Dis 2018;77:1251–1260.

[2]De Bruin M. et al. Coding manual for behavioral change techniques. Maastricht University, 2007.

Acknowledgements

We thank all participants for their collaboration

Disclosure of Interests

None declared

Stability investigation of a cryo soft x-ray microscope by fiber interferometry

We present a stability investigation of the Stockholm laboratory cryo soft x-ray microscope. The microscope operates at a wavelength of 2.48 nm and can image biological samples at liquid-nitrogen temperatures in order to mitigate radiation damage. We measured the stability of the two most critical components, sample holder and optics holder, in vacuo and at cryo temperatures at both short and long time scales with a fiber interferometer. Results revealed vibrations in the kHz range, originating mainly from a turbo pump, as well as long term drifts in connection with temperature fluctuations. With improvements in the microscope, earlier stability issues vanished and close-to diffraction-limited imaging could be achieved. Moreover, our investigation shows that fiber interferometers are a powerful tool in order to investigate position-sensitive setups at the nanometer level.

Ki67 and lymphocytes in the pretherapeutic core biopsy of primary invasive breast cancer: positive markers of therapy response prediction and superior survival

Background Core needle biopsy plays a crucial role as diagnostic tool for BC. Both Ki67 and likely tumor-infiltrating lymphocytes (TILs) in the near future are determining the kind of systemic therapy. The role of TILs in BC is still an issue for clinical research, albeit preliminary results of neoadjuvant and adjuvant clinical studies already now highlight the crucial impact of TILs on therapy response and survival. Methods Evaluation of related publications (pubmed) and meeting abstracts (ASCO, SABCS). Results The monoclonal antibody Ki67 recognizing a nuclear antigene in proliferating cells is a positive marker of therapy response and superior survival. Endocrine responsive tumors of low proliferation (Ki67 < 14%/11%) respond to tamoxifen, in contrast postmenopausal tumors with higher proliferation respond better to aromatase-inhibitors. Pathological complete response (pCR)-rates increase in tumors with higher proliferation (Ki67 > 19%) vs. tumors with lower proliferation after neoadjuvant chemotherapy (NAC). pCR-rates of up to 60% can be seen in TNBC and HR-, HER2+BC, lower pCR-rates, however, in HR+, HER2- BC. Increased stromal TILs are found in 30% of TNBC and in 19% of HR-, HER2+BC. The percentage of TILs is a significant independent parameter for pCR after NAC. Lymphocyte-predominant BC (LPBC) respond with higher pCR-rates than non-LPBC or tumors without any TILs. Increased TILs in TN and HR-, HER2+ subtypes predict benefit from addition of carboplatin to NAC. TILs are also associated with improved DFS and OS among patients with TNBC and HR-, HER2+ BC. Conversly and interestingly increased TILs in patients with HR+, HER2-(luminal) BC are associated with a 10% higher risk of death per 10% increase of TILs. Interactions between immune system and cancer are complex. The cancer-immunity cycle characterizes these interactions. BC subtypes with higher number of mutations such as TNBC and HR-, HER2+BC are considered to provide a raising number of tumor-associated antigens, thereby capable to build up a higher endogenous immune response. TILs may serve as surrogate marker of both an existing endogenous immune response and the probability to respond to cancer immune therapies. As cancer co-opt immune checkpoint-pathways as a major mechanism of immune resistance, in particular, against cytotoxic T-cells, blockades of checkpoint-pathways by antibodies are one of the goals of the current cancer immunotherapy studies. Therapy studies with antigene-based strategies (vaccines) and antibodies against the immune checkpoints PD-1 and CTLA-4 and their inhibitory pathways in order to enhance cytotoxic T-cell activities against cancer cells with or without chemotherapy are underway. Conclusions It can be suggested that the use of multigene expression testing will increase in order to select more clearly primary HR+, HER2- BC patients with intermediate recurrence risk who likely may benefit from chemotherapy. Furthermore Ki67 and the multigene expression test Oncotype DX can act as dynamic markers to avoid cytostatic overtreatment and endocrine undertreatment. A data-derived optimal Ki67 cut point for pCR and DFS as well as OS is currently not feasible. The integration of stromal TILs into the immunohisto-pathological report after their evaluation has been standardized is likely helpful to determine patients who profit by additional carboplatin chemotherapy. Oncologists need an enlarged information about the tumor-microenvironment in future. The preliminary results of current BC immunotherapy studies are encouraging.

ERCC1 as a predictor of response to induction therapy for stage III non-small cell lung cancer

e18511

Background: Neoadjuvant platinum-based chemotherapy in stage III NSCLC offers the chance to eradicate occult metastases and decrease tumor volume, thus improving curative surgical resection rates. A remission after induction therapy is correlated with prolonged survival. However, only 40-50% of patients respond to therapy since there is still no validated predictor for the benefit of platinum based chemotherapy. As DNA repair mechanisms are related with resistance of lung cancer cells to platinum-based chemotherapy, aim of the study was to compare ERCC1 level in lymph node metastases with the degree of pathologic tumor regression after induction treatment and surgery. Methods: From July 2004 to June 2009, 46 NSCLC patients with clinically staged IIIA (N = 32) or IIIB (N = 14) NSCLC underwent at least two cycles of platinum-based induction chemotherapy and combined radio-chemotherapy. After restaging radical surgery was performed. ERCC1 was determined from pretreatment samples of metastatic nodes taken on mediastinoscopy. Real time RT-PCR assays were performed to determine ERCC1 mRNA expression. Tumor regression has been classified on surgical specimen using an score system ranging from grade I (pCR) to grade VI (non-responder). The samples were categorized into three groups according to their ERCC1 expression values and in two groups according to their chemotherapy response (either pCR or non-pCR). Results: A significant correlation between the ERCC1 expression level and the chance to achieve a pCR during a platinum-based chemotherapy could be demonstrated in our samples (P<0.05). Furthermore, the median overall survival in the pCR group was 44 vs. 29 month in the non-pCR group (HR 0.33 [95%-CI: 0.02-1.15]; P=0.06). However, no direct correlation between ERCC1 expression and local or distant metastasis formation could be found. Conclusions: Assessment of ERCC1 mRNA expression in pretreatment tumor tissue is feasible in the clinical setting and predicts response to platinum-based induction therapy. Additional studies are warranted to optimize methodologies for ERCC1 analysis in small tumor samples and to redefine induction protocols on an individual basis, thus enhancing response rates and perhaps outcome.

High average brightness water window source for short-exposure cryomicroscopy

Laboratory water window cryomicroscopy has recently demonstrated similar image quality as synchrotron-based microscopy but still with much longer exposure times, prohibiting the spread to a wider scientific community. Here we demonstrate high-resolution laboratory water window imaging of cryofrozen cells with 10 s range exposure times. The major improvement is the operation of a λ=2.48 nm, 2 kHz liquid nitrogen jet laser plasma source with high spatial and temporal stability at high average brightness >1.5×10(12) ph/(s×sr×μm(2)×line), i.e., close to that of early synchrotrons. Thus, this source enables not only biological x-ray microscopy in the home laboratory but potentially other applications previously only accessible at synchrotron facilities.

Compact x-ray microscope for the water window based on a high brightness laser plasma source

We present a laser plasma based x-ray microscope for the water window employing a high-average power laser system for plasma generation. At 90 W laser power a brightness of 7.4 x 10(11) photons/(s x sr x μm(2)) was measured for the nitrogen Lyα line emission at 2.478 nm. Using a multilayer condenser mirror with 0.3 % reflectivity 10(6) photons/(μm(2) x s) were obtained in the object plane. Microscopy performed at a laser power of 60 W resolves 40 nm lines with an exposure time of 60 s. The exposure time can be further reduced to 20 s by the use of new multilayer condenser optics and operating the laser at its full power of 130 W.

Correlation between in vitro chemotherapy sensitivity and PARP-1 expression in patients with breast cancer

10627

Background: Based on its potential use as a therapeutic target through PARP inhibitors expression of Poly-A-Ribose-Polymerase-1 (PARP-1) has come into scientific focus. Furthermore, it could be demonstrated that cytoplasmic PARP-1 expression varies depending on molecular breast cancer subtypes and that it correlates with an increased response to neoadjuvant taxane-anthrazykline containing chemotherapy (von Minckwitz et al., J Clin Oncol 2011). In-vitro-chemotherapy sensitivity and resistance assays (CSRAs) are a means to directly measure chemotherapy sensitivity in a given tumor uninfluenced by host factors. Methods: We conducted a systematic immunohistochemical tissue-microarray (TMA)-based analysis of 550 samples of invasive breast cancers to evaluate the expression of a set of molecular markers including estrogen receptor (ER), progesterone receptor (PR) and HER2 as well as PARP-1. Triple negative breast cancers (TNBC) were identified through lack of (over-)expression of ER, PR and HER2. All carcinomas were analyzed in an in vitro CSRA protocol for epirubicin/docetaxel (ED) and epirubicin/cyclophosphamide (EC). In-vitro-chemotherapy sensitivity was analyzed using an adenosine triphosphate (ATP) bioluminescence assay. Results: Moderate/high expression of PARP-1 was found in 48 and 33% of cases with TNBC and non-TNBC, respectively (p=0.015). No correlation between TNBC phenotype and cytoplasmic expression was observed. However, increased expression of both cytoplasmic and nuclear PARP-1 was correlated with an increased in-vitro sensitivity against ED (p=0.012 and 0.025, respectively) but not EC (p=0.27 and 0.62, respectively). Conclusions: Our results support previous observations demonstrating a significant correlation between expression of PARP-1 and an increased sensitivity against taxane-anthracycline chemotherapy independent of tumor phenotype.

Laboratory cryo soft X-ray microscopy

Lens-based water-window X-ray microscopy allows two- and three-dimensional (2D and 3D) imaging of intact unstained cells in their near-native state with unprecedented contrast and resolution. Cryofixation is essential to avoid radiation damage to the sample. Present cryo X-ray microscopes rely on synchrotron radiation sources, thereby limiting the accessibility for a wider community of biologists. In the present paper we demonstrate water-window cryo X-ray microscopy with a laboratory-source-based arrangement. The microscope relies on a λ=2.48-nm liquid-jet high-brightness laser-plasma source, normal-incidence multilayer condenser optics, 30-nm zone-plate optics, and a cryo sample chamber. We demonstrate 2D imaging of test patterns, and intact unstained yeast, protozoan parasites and mammalian cells. Overview 3D information is obtained by stereo imaging while complete 3D microscopy is provided by full tomographic reconstruction. The laboratory microscope image quality approaches that of the synchrotron microscopes, but with longer exposure times. The experimental image quality is analyzed from a numerical wave-propagation model of the imaging system and a path to reach synchrotron-like exposure times in laboratory microscopy is outlined.

Prediction of Metastasis in Node-Negative, Hormone Receptor Positive, Tamoxifen Adjuvant Treated Primary Breast Cancer Patients Using Ki-67 (IHC) and RT-PCR Based 14-Gene Prognostic Signature

Background: Risk estimation based on the recommendations of St. Gallen Consensus commonly decides for additional cytostatic therapy in node-negative (N-), hormone receptor positive (HR+) primary breast cancer patients. High proliferative activity in the HR+ subtype confers a 19-fold relative risk of relapse compared with HR+ tumors of low proliferative activity. Furthermore immunohistochemically determined Ki-67 is characterized as a Luminal B marker that identifies a high risk subgroup in HR+, N- breast cancer patients.Aim of this investigation was to compare risk estimation using Ki-67 (%) with the results of a RT-PCR based multi-gene prognostic signature. Methods: Tumor tissues of totally 321 unselected primary breast cancer patients were formalin fixed and routinely processed for immunohistochemical determination and scored for protein expression of ER, PgR and Ki-67. HER2 was determined using dd-PCR. Content of both hormone receptors and proliferation activity were evaluated counting positively coloured nuclei from at least 100 tumor cells. The median follow up was 61 months. To calculate the cut off for high proliferation Ki-67 values were subjected to a log rank CART analysis. High proliferation was defined by Ki-67 of 19% and more. With this cut off it was possible to distinguish significantly various patient cohorts (N-, pT1, postmenopausal) into two different risk groups regarding metastasis free survival. The definition of low risk was low proliferation and HER2 negativity, of high risk high proliferation or HER2 positivity. The risk for metastasis of 16 new primary breast cancer patients was estimated based on two surrogate risk groups and the multi-gene prognostic signature. Results: Tamoxifen adjuvant treated HR+, HER2-, low proliferating (Ki-67 &lt;19%), N- low risk patients (N= 68) and HR+, HER2-, high proliferating/HR+, HER2+, N- high risk patients (N= 84) showed a recurrence rate of 2.94% and 27.4%, respectively (P&lt; .000). In the ongoing observation study all 5 low proliferating HER2- tumors had a low risk gene prognostic signature. From 11 high proliferating HER2- patients one patient had a low risk gene signature (9%), 3 patients a moderate risk gene signature (27%) and 7 patients a high risk gene signature (64%). Conclusion: Despite the small number of patients investigated up to now (N= 16) the preliminary results appear to show that low proliferative activity is associated with a low risk gene prognostic signature, whereas high proliferation means only in part a high risk gene prognostic signature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6025.

Gene Expression Profiling for Therapy Prediction in a Breast Cancer Neoadjuvant Therapy Study Applying Docetaxel/Epirubicin/Cyclophosphamide

Background: Gene expression profiling is a powerful tool to identify markers associated with clinical and therapy outcome of cancer patients. Prediction of the response to neoadjuvant regimens remains a persistent challenge. Aim of this ongoing study is the development of a gene set predicting the response of the tumor to a taxane- anthracycline based neoadjuvant chemotherapy.Material and Methods: Microarray expression profiling was performed on biopsy samples from patients before treatment using Human Genome Survey microarrays (HGSM). The protocol for a phase II study was elaborated for the treatment of breast cancer patients suffering from a primary tumor 1.5 cm or inflammatory breast cancer with Docetaxel/Epirubicin/Cyclophosphamide (TEC) prior to surgical treatment. The study was approved by the local ethical committee and all patients signed an informed consent.Results: Overall 80 patients have been enrolled in the presented study. High quality gene expression data were available from 58 patients. Of these patients 21 responded to the TEC regimen (pCR or MIB1 expressing cells in the residual tumor &lt;= 5% and decrease of Mib1-expression &gt;= 20%). Based on the gene-expression profile we were able to identify a preliminary gene set of 150 genes which allows us to separate responding tumors from the non responding ones based on their gene expression profile. A comparable separation of the groups could not achieved by established tumor markers, e.g. ER, PgR, HER2, uPA etc. which are measured simultaneously on the HGSM. Among the genes distinguishing the two groups several genes normally expressed in mononuclear blood cells were identified, pointing to the presence of tumor infiltrating leukocytes, predominantly in the tumors responding the TEC regimen. The presence of these cells has already been verified in a subset of the samples.Conclusion: We identified a gene set which allows to select patients who will benefit from neoadjuvant chemotherapy. Furthermore at least in the so far investigated samples tumor infiltrating leukocytes are significantly more often found in tumors which respond to a taxane- anthracycline based neoadjuvant chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2039.

Molecular targeted therapies for breast cancer treatment

Targeting the oestrogen receptor, HER2 (human epidermal growth factor receptor 2) and vascular endothelial growth factor has markedly improved breast cancer therapy. New targeted therapeutic approaches to induction of apoptosis or inhibition of anti-apoptosis, cell cycle progression, signal transduction and angiogenesis are described. The molecular pathways and their inhibitory or repair mechanisms are discussed in the preclinical and clinical settings.

Compact Zernike phase contrast x-ray microscopy using a single-element optic

We demonstrate Zernike phase contrast in a compact soft x-ray microscope using a single-element optic. The optic is a combined imaging zone plate and a Zernike phase plate and does not require any additional alignment or components. Contrast is increased and inversed in an image of a test object using the Zernike zone plate. This type of optic may be implemented into any existing x-ray microscope where phase contrast is of interest.

A 9 keV electron-impact liquid-gallium-jet x-ray source

We demonstrate a high-brightness compact 9 keV electron-impact microfocus x-ray source based on a liquid-gallium-jet anode. A approximately 30 W, 50 kV electron gun is focused onto the approximately 20 ms, 30 mum diameter liquid-gallium-jet anode to produce an approximately 10 microm full width at half maximum x-ray spot. The peak spectral brightness is >2 x 10(10) photons(s mm(2) mrad(2)x0.1% BW). Calculation and experiments show potential for increasing this brightness by approximately three orders of magnitude, making the source suitable for laboratory-scale x-ray crystallography and hard x-ray microscopy.

Semi-quantitative gene expression profiling for therapy prediction in a breast cancer neoadjuvant therapy study applying docetaxel/epirubicin/cyclophosphamide

21144

Background: More than 28000 curated human genes can be analyzed semi-quantitatively using a chemiluminescent detection technology and 60mer oligonucleotides on a Human Genome Survey Microarray (HGSM, Applied Biosytems). Methods: HGSM expression profiling was performed on biopsy samplesfrom a setting of patients under neoadjuvant treatment. The protocol for a phase II study was elaborated for the treatment of breast cancer patients suffering from a primary tumor > 1,5 cm or inflammatory breast cancer with Docetaxel / Epirubicin/Cyclophosphamide (TEC) prior to surgical treatment. The study was approved by the local ethical committee and 80 patients will be included into the study after written informed consent. 40 patients have been already included in the ongoing study. In this prospective study a biopsy from the tumor is taken before chemotherapy. Therefore, success of treatment is detectable directly at the operated residual tumor. Our results demonstrate a low rate of false-positives (1.2%), a high specificity and quantification accuracy of HGSM system. Comparison of data from HGSM and RT-PCR obtained on mRNA from fresh frozen tissue resulted a Pearson-correlation of 0.92 to 0.63 for the breast cancer genes. Results: Tumour response (pCR, pPR) of more than 70 % can be achieved using neoadjuvant TEC- regimen. 25 % of pCR in this study is comparable with data of other published neoadjuvant trails. First expression profiling results are obtainable showing that a subset of 148 genes indicates patients with complete remission (pCR, no detectable tumor at end of chemotherapy), partial remission (pPR) and progressive disease (pPD). Remarkable, that the expression profile clearly separated pCR and pPD tumors whereas pPR tumors presented with a closer relationship to pPD tumors than to pCR tumors but displayed small specific subprofiles. A comparable separation of the groups could not achieved by established tumor markers, e.g. ER, PgR, HER2, uPA etc. which are measured simultaneously on the HGSM. Conclusions: HGSM expression profiling is promising to have the potential to figure out genes that are related to cancer progression and chemotherapy resistance, especially in PST.

No significant financial relationships to disclose.

Whole genome expression analysis for biologic rational pathway modeling: application in cancer prognosis and therapy prediction

Using semi-quantitative microarray technology, almost every one of the approximately 30 000 human genes can be analyzed simultaneously with a low rate of false-positives, a high specificity, and a high quantification accuracy. This is supported by data from comparative studies of microarrays and reverse-transcription PCR for established cancer genes including those for epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2/ERBB2), estrogen receptor (ESR1), progesterone receptor (PGR), urokinase-type plasminogen activator (PLAU), and plasminogen activator inhibitor-1 (SERPINE1). As such, semi-quantitative expression data provide an almost completely comprehensive background of biological knowledge that can be applied to cancer diagnostics. In clinical terms, expression profiling may be able to provide significant information regarding (i) the identification of high-risk patients requiring aggressive chemotherapy; (ii) the pathway control of therapy predictive parameters (e.g. ESR1 and HER2); (iii) the discovery of targets for biologically rational therapeutics (e.g. capecitabine and trastuzumab); (iv) additional support for decisions about switching therapy; (v) target discovery; and (vi) the prediction of the course of new therapies in clinical trials. In conclusion, whole genome expression analysis might be able to determine important genes related to cancer progression and adjuvant chemotherapy resistance, especially in the context of new approaches involving primary systemic chemotherapy. In this review, we will survey the current progress in whole genome expression analyses for cancer prognosis and prediction. Special emphasis is given to the approach of combining biostatistical analysis of expression data with knowledge of biochemical and genetic pathways.

Surgery in the tri-modality treatment of small cell lung cancer.Stage-dependent survival

OBJECTIVE

Patients with small cell lung cancer (SCLC) are frequently denied surgical treatment despite growing body of evidence for a longer duration of remission and overall survival, if surgical intervention is integrated in a tri-modality therapy concept including chemotherapy, surgery, and radiotherapy.

METHODS

A retrospective analysis was performed using data derived from 95 patients with SCLC operated upon over a period of 9 years. A subset of these patients was primarily operated upon and being diagnosed as SCLC only after thoracotomy, received radio-/chemotherapy postoperatively (n=64, group I). The second cohort had surgery after neoadjuvant chemotherapy which was continued postoperatively in addition to thoracic and cranial radiotherapy (n=31, group II). The patients in the second group were further divided into two subgroups: complete histological regression of tumor tissue in the mediastinal lymph nodes (group IIA), and those with persistent mediastinal lymph nodal involvement detected after thoracotomy (group IIB).

RESULTS

Group I patients had stage I or II disease, whereas group II patients had clinical stage IIIA or IIIB. The overall 30-day mortality rate was as low as 5%. The median survival was 31.3 months for patients in group I, 31.7 months for adjuvant surgery with complete regression of mediastinal nodes (group IIA), and 12.4 months for adjuvant surgery without regression of mediastinal nodes (group IIB).

CONCLUSIONS

Surgical intervention is promising and warrants prospective trials to be evaluated as an important adjunct to multi-modality therapy regimen in SCLC as regards to its impact on relapse free and overall survival.

Medical Uses of Cosmetic Colored Contact Lenses

PURPOSE

To explore the clinical issues surrounding the use of hand-painted contact lenses for medical indications and to assess patient satisfaction with the use of these lenses for an unsightly eye.

METHODS

A questionnaire was sent to all patients visiting the contact lens department of Western Eye Hospital for a colored contact lens fitting during a 1-year period. The questionnaire related to patient satisfaction with the lenses and aspects of wear.

RESULTS

Replies were received from 25 of a total of 33 patients. The average wearing time was 11.3 hours per day. Most (88%) patients wore lenses for cosmetic reasons, and 12% wore lenses for cosmetic and refractive purposes. Satisfaction was 76% regarding lens comfort and 88% regarding lens color.

CONCLUSIONS

Provided lens care is satisfactory and the patient does not have unreasonable expectations, a tinted contact lens can be a useful device. In view of the cost implication, this is a valuable service provided by the hospital.

Therapy prediction in a breast cancer primary systemic chemotherapy (PST) study applying docetaxel/epirubicin/cyclophosphamide (TEC) by gene expression profiling

10049

Background: Currently there are no tests to assist in selecting the optimal PST regimen for breast cancer patients. Primary study goals of this prospective, single-armed multicentric investigation are pathologically confirmed tumor response and the rate of breast conserving therapy (BCT). Secondary goals are to find histopathologic and gene profiling patterns best correlating with tumor remission in a taxane- anthracycline based neoadjuvant setting as well as to evaluate cytostatic toxicity and quality of life. Methods: In this phase II study of totally 40 eligible patients with invasive breast cancer Human Genome Survey Microarray (HGSM) expression profiling is performed on jet-biopsy sample basis. The protocol was elaborated for the treatment of patients suffering from a primary tumor with 6 cycles of TEC (3-weekly) prior to the surgical treatment. The selection of predictor genes was done with BRB-ArrayTools Version 3.3 using a model based on the Compound Covariate Predictor, Diagonal Linear Discriminant Analysis, Nearest Neighbor Classification, and Support Vector Machines with linear kernel.We estimated the prediction error of each model using leave-one-out cross-validation (LOOCV) as described by Simon R. 2000 random permutations were used. Clustering was done using Cluster 3.0 and Java TreeView 1.0.12. Results: Tumor response (pCR, pPR) of more than 70% can be achieved using neoadjuvant TEC-regimen. 22% pCR (ypT0; ypN0) and 90% BCT in this study are comparable with data of other published PST trials. Preliminary expression profiling results reveal a subset of 148 genes that classifies all patients with a complete remission (pCR), in one cluster with a very closely related gene expression pattern (n=5; PPV = 100%). Furthermore 10 patients defined as responders due to selected MIB1-expression based criteria (expressing cells in the residual tumor ≤ 5% and a Δ MIB1-expression ≥ 20%) can be correctly classified in 9 of 10 cases. Comparable separation of the groups could not be achieved by established tumor factors. Conclusions: HGSM expression profiling is promising to have the potential to figure out genes that are related to chemotherapy response, especially in PST.

No significant financial relationships to disclose.

Comparison of various types of stiffness as predictors of the load-bearing capacity of callus tissue

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis. Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness.

Breast tumour growth inhibition in vitro through the combination of cyclophosphamide/metotrexate/5-fluorouracil, epirubicin/cyclophosphamide, epirubicin/paclitaxel, and epirubicin/docetaxel with the bisphosphonates ibandronate and zoledronic acid

Breast cancer has a significant capacity to metastasize to bone. Bisphosphonates are the standard treatment for hypocalcaemia of malignancy (HCM), which is a common complication of bone metastasis. The combination of bisphosphonates with standard anticancer drugs such as paclitaxel or tamoxifen results in a synergistic apoptotic effect greater than that produced by either single agent alone. Potential antitumour effects in vitro of the two bisphosphonates zoledronic acid (Zol) and ibandronate (Ib) (each at 30 microM) combined with different anticancer drug combinations: cyclophosphamide/metotrexate/5-fluorouracil (CMF), epirubicin/cyclophosphamide (EC), epirubicin/paclitaxel (ET), and epirubicin/docetaxel (EDoc) were investigated using ATP-cell viability assay (ATP-CVA). Twenty cases of female primary, invasive breast cancer were assessed. Ibandronate and zoledronic acid alone showed an inhibitory effect on breast cancer tumour cells in vitro. The breast tumour growth inhibition effect for those two drugs amounted to 22 and 25% respectively. Inhibitory effects were clearly visible for all four combinations of anticancer drugs together with both bisphosphonates. Combinations of anticancer drugs with zoledronic acid seem to be more effective with respect to tumour growth inhibition than combinations with ibandronate.

High-throughput analysis of genome-wide receptor tyrosine kinase expression in human cancers identifies potential novel drug targets

Novel high-throughput analyses in molecular biology allow sensitive and rapid identification of disease-related genes and drug targets. We have used quantitative real-time reverse transcription-PCR reactions (n = 23000) to analyze expression of all human receptor tyrosine kinases (n = 56) in malignant tumors (n = 313) of different origins and normal control samples (n = 58). The different tumor types expressed very different numbers of receptor tyrosine kinases: whereas brain tumors and testicular cancer expressed 50 receptor tyrosine kinases, acute myeloid leukemia (AML) samples expressed only 20 different ones. Specimens of similar tumor origin exhibited characteristic receptor tyrosine kinase expression patterns and were grouped together in hierarchical cluster analyses. When we focused on specific tumor entities, receptor tyrosine kinases were identified that were disease and/or stage specific. Leukemic blasts from AML bone marrow samples differed significantly in receptor tyrosine kinase expression compared with normal bone marrow and purified CD34+ cells. Among the differentially expressed receptor tyrosine kinases, we found FLT3, c-kit, CSF1 receptor, EPHB6, leukocyte tyrosine kinase, and ptk7 to be highly overexpressed in AML samples. Whereas expression changes of some of these were associated with altered differentiation patterns (e.g., CSF1 receptor), others, such as FLT3, were genuinely overexpressed in leukemic blasts. These data and the associated database (http://medweb.uni-muenster.de/institute/meda/research/) provide a comprehensive view of receptor tyrosine kinase expression in human cancer. This information can assist in the definition of novel drug targets.

Quantitative analysis of the in situ Fourier transform infrared absorption and emission spectrum of gas-phase SiO (Deltav = 1 and 2) produced in Si-N-O fiber growth

The in situ Fourier transform infrared (FT-IR) spectrum of gasphase SiO produced in silicon oxynitride fiber growth has been quantitatively analyzed. Both absorption and emission FT-IR spectra at a spectral resolution of 0.5 cm(-1) were produced from the reaction zone at 1450 degrees C. The fundamental and hot bands were observed with vibrational levels up to v = 7. For the purposes of quantitative analysis the individual vibration-rotation integrated line strengths for the three main isotopes,( 28)SiO,( 29)SiO, and( 30)SiO, were calculated based on ab initio quantum chemical calculations of the electric dipole moment function and the transition moment. Vibrational anharmonicity and Hermann-Wallis correction factors were also incorporated. From the line strengths at specific temperatures and the known Dunham coefficients, the absorbance spectrum was simulated with best fits giving the averaged SiO concentration in the 400 mm reaction zone of 1.0 x 10(17) molecules/cm(3). Such quantitative measurements demonstrate the power of in situ infrared (IR) spectroscopy combined with quantum chemical calculations. The rapid determination of synthetic calibration datasets for chemometric analysis can thus lead to correlation of gas-phase species concentrations with fiber growth properties and subsequently to real-time process control.

Contact Lens Prescribing in a Specialist Medical Contact Lens Clinic Based in an NHS Hospital

PURPOSE

To describe the range of indications for contact lenses and the types of lenses being used in an NHS hospital-based specialist medical contact lens clinic and contrast this with information from 12 years ago.

METHODS

A retrospective audit of 596 clinic attendances was performed in the contact lens clinic at the Western Eye Hospital between April 2002 and March 2003. The results were compared with a similar audit performed in 1991. We used the hospitals electronic records, and information on contact lens prescribing was obtained directly from the receipts generated by the contact lens department and the accounts department.

RESULTS

We saw 392 patients with 88.5% of patients requiring 2 or less visits per year. The majority of referrals are for high myopia (28.6%) closely followed by aphakia (25.2%) and keratoconus (24.7%). This is in contrast to 1991 when 68% of referrals were for aphakia and twice as many myopes (17%) were seen as keratoconus patients (8%). A total of 560 lenses were prescribed with 68 different types of lens in use. The seven most commonly used lens types accounted for 61% of all lenses prescribed.

CONCLUSIONS

Medical contact lens clinics provide a specialist service and also provide an important training resource for junior ophthalmologists. Safer cataract surgical techniques have had a significant impact on the case mix seen in our clinic, with the emphasis moving away from aphakic and myopic patients and toward the more challenging to fit eyes with keratoconus or postcorneal surgery.

[Impact of DNA image cytometry (ICM) parameter and established prognostic factors on disease free survival (DFS) and overall survival (OS) of node-negative breast cancer (NNBC) patients]

OBJECTIVE

DNA ICM allows measurement of nuclear DNA content and genotypical grading of malignancy. The aim of this study was to prove the prognostic value of DNA parameter in comparison to established prognostic factors for DFS and OS.

PATIENTS AND METHODS

Cytological imprints of 177 unselected primary NNBC patients were subjected to ICM. ICM parameter 2cDI, 5cEE, 9cEE, DNA mean value, proliferation fraction (SG2M) and ploidy were investigated together with established parameter like pT-stages, histology, grading, hormone receptor status and patient age regarding DFS and OS. Univariate and multivariate analysis were performed.

RESULTS

Univariate analysis revealed that except ploidy all ICM parameter and pT-stages, histology as well as grading were significant prognostic factors for DFS. However, only 2cDI and pT-stages were proved independent prognostic factors in multivariate analysis. Regarding OS 9cEE, histology and pT-stages were significant factors in univariate analysis. However, only 9cEE and pT-stages were found to be independent prognostic factors in multivariate analysis.

CONCLUSIONS

DNA - ICM parameter 2cDI and 9cEE together with pT-stages were proved independent prognostic factors in NNBC patients.

[Remission rate of mediastinal lymph nodes after multimodal therapy of lung cancer--is it a prognostic factor?]

OBJECTIVE

General acceptance in the oncologic community has been gained for combined modality treatment of non-small cell lung (NSCLC) cancer in locally advanced stage IIIA and IIIB disease. However, no optimal regimen has been established. This study (chemotherapy and radiochemotherapy followed by operation) assesses feasibility, response, resectability, and survival in patients with stage IIIA and IIIB lung cancer. Currently, only little data is available about the prognostic significance of tumor clearance of mediastinal nodes. Thus, an important aim of our study was to evaluate the prognostic significance of the extent of tumor reduction in mediastinal nodes by a neoadjuvant multimodality protocol.

PATIENTS

In a phase II protocol, 26 patients underwent neoadjuvant radiochemotherapy. Subsequently, a radical lymphadenectomy was performed during surgery. The extent of tumor regression was determined according to the methodology initially described by Salzer-Kuntschik for osteosarcoma: Grade I: no vital tumor cells, grade II: some tumor cells, grade III: less than 10 % vital tumor cells, grade IV: 10-50 % vital tumor cells, grade V: more than 50 % vital tumor cells, grade VI: no effect of chemotherapy.

RESULTS

Complete pathologic response was seen in 30.7 % of primary tumors, in 38.5 % of mediastinal lymph nodes, and in 23 % of corresponding specimens simultaneously. Median survival was 34.7 months for those patients with grade I, 12.6 months with grade II, and 8.9 months for patients showing a grade III/IV regression in mediastinal nodes. Response rate to neoadjuvant chemotherapy in mediastinal nodes proved to be the only statistically significant parameter for long-term survival: In cases with no vital tumor cells in the operation specimen, median survival was 34.7 months in comparison to those with vital cells showing a median survival of only 11.4 months (P = 0.01).

CONCLUSION

Patients with locally advanced NSCLCs can enjoy long-term survival after multimodal therapy. However, the complications related to therapy are considerably. Especially, clearance of tumor cells from mediastinal lymph nodes is an important independent prognostic factor.

A phase II single-institution study of neoadjuvant stage IIIA/B chemotherapy and radiochemotherapy in non-small cell lung cancer

BACKGROUND

The relevance of a trimodal strategy in the treatment of lung cancer, consisting of neoadjuvant radiochemotherapy followed by surgery, is a subject of ongoing clinical trials. We tested whether improvement of long-term survival can be achieved for patients with stage III non-small cell lung cancer by this therapeutic approach.

METHODS

We performed a retrospective analysis of a single-institution phase II study. Of 33 patients enrolled in the protocol between 1992 and 1995, we reviewed the clinical outcomes of 26 patients with locally advanced non-small cell lung cancer (stage IIIA and IIIB), which had been resected after combined chemotherapy and radiochemotherapy.

RESULTS

After neoadjuvant therapy, resection of the tumor was accomplished in all patients, and R0 resection was achieved in 92%. Histologic remission was found in 76% of these patients. Involvement of mediastinal lymph nodes was crucially important for the outcome. First, histologic clearance of the mediastinal compartment by neoadjuvant therapy resulted in a 27% 5-year survival rate. Second, patients with viable tumor in any of the mediastinal lymph nodes removed had a poor outcome (median survival 11.4 and 34.7 months in patients with and without viable tumor cells in the specimens, respectively; p = 0.01).

CONCLUSIONS

Histopathologic regression after neoadjuvant multimodal therapy including chemotherapy and radiotherapy was an important prognostic factor in a selected group of patients with locally advanced lung cancer.

Cyclin A1 is highly expressed in aggressive testicular germ cell tumors

Cyclin A1 is a tissue-specific A-type cyclin that is essential for spermatogenesis. Overexpression of cyclin A1 was found in acute myeloid leukemia and cyclin A1 induced leukemia in a transgenic mouse model. We used quantitative real-time reverse transcription-polymerase chain reaction to analyze cyclin A1 expression in solid tumors. Cyclin A1 expression was very low in breast cancer, non-small cell lung cancer and in cervical carcinoma. However, substantial expression of cyclin A1 was found in testicular and ovarian cancer and in endometrial cancer. In testis specimens, cyclin A1 expression was much higher in testicular tumors compared to Sertoli cell only syndrome that lacks spermatogenesis. Compared to normal spermatogenesis, testicular cancers expressed on average lower levels of cyclin A1. Among the different histological subtypes of testicular tumors, embryonal cell carcinomas and immature teratomas expressed the highest levels of cyclin A1. The cyclin A1 levels in these tumors were similar to those seen in normal testis. Seminomas and yolk sac tumors expressed intermediate levels, whereas cyclin A1 expression was very low in mature teratomas. These findings indicate that cyclin A1 is expressed in selected solid tumors. Its known oncogenic function and the high expression levels in aggressive testicular tumors suggest a role for cyclin A1 in germ cell tumorigenesis.

C-myc, not HER-2/neu, can predict recurrence and mortality of patients with node-negative breast cancer

BACKGROUND

At present, node-negative, high-risk breast cancer patients cannot be identified with sufficient accuracy. Consequently, further strong prognostic factors are needed.

METHODS

Among 181 node-negative breast cancer (NNBC) patients, c-myc and HER-2/neu oncogenes were identified prospectively using double differential PCR. The possible impact of amplification of those oncogenes on disease-free survival (DFS) and overall survival was examined. Furthermore, the possible effects of adjuvant therapies on rate of recurrence and mortality in oncogene-amplified NNBC patients were investigated.

RESULTS

The prevalence rates for amplification of c-myc and HER-2/neu were 21.5% and 30.4%, respectively. On univariate analysis, c-myc-amplified NNBCs were associated with significantly shorter DFS at 36 months after the initial diagnosis (85.3% versus 97.3%). As compared with nonamplified cancers, HER-2/neu-amplified NNBCs did not exhibit any significant differences after 36 months and 95 months. Multivariate analysis indicated that c-myc amplification and tumour size, in contrast to HER-2/neu amplification, oestrogen receptor status, grading and age, were the only independent parameters for DFS. During the period of observation, we found no evidence for an impact of amplification of the oncogenes on overall survival in all cases. With respect to various adjuvant systemic therapies such as chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil; fluorouracil, epirubicin, cyclophosphamide) and endocrine therapy (tamoxifen), no significant differences were identified in oncogene-amplified NNBC patients in terms of DFS and overall survival. However, those c-myc-amplified NNBC patients who did not receive adjuvant systemic therapy exhibited significantly shorter DFS and overall survival as compared with c-myc-nonamplified patients.

CONCLUSION

C-myc amplification appears to be a strong prognostic marker with which to predict early recurrence in NNBC patients. C-myc-amplified NNBC patients without adjuvant systemic therapy experienced shorter DFS and overall survival.

p53 Gene status in relation to ex vivo chemosensitivity of non-small cell lung cancer

PURPOSE

About 40% of non-small cell lung cancer (NSCLC) patients are candidates for systemic chemotherapy, despite the fact that at diagnosis most NSCLC are usually chemoresistant both in vivo and ex vivo. It is important to develop sufficient methods of prediction of the response to chemotherapy and to find molecular markers that may prognose this response. Therefore, a study on the relationship of p53gene status to the ex vivo chemosensitivity of primary human NSCLC was performed.

METHODS

Three drug combinations (carboplatin/etoposide, cyclophosphamide/etoposide/epirubicin, and paclitaxel/carboplatin) were tested in a modified ATP cell viability assay. A group of 28 cases of primary human NSCLC was assessed.

RESULTS

Ex vivo chemosensitivity testing showed that tumors with p53 mutations were significantly more resistant to the cyclophosphamide/etoposide/epirubicin regimen than with normal p53 gene ( P = 0.012). However, no correlation was observed for two other treatment regimens.

CONCLUSION

Mutations in the p53gene can lead to enhanced chemoresistance, confirming the hypothesis that the p53 gene may serve as a marker of tumor response to treatment in NSCLC. However, the data also illustrate that some additional factors might contribute to drug resistance of the examined tumors.

Characteristics and functional outcomes of 130 patients with keratoconus attending a specialist contact lens clinic

AIMS

To evaluate the demographic profile, management and functional outcomes of patients with keratoconus attending the contact lens clinic of a tertiary ophthalmic referral centre over a one year period.

METHODS

A retrospective cohort analysis was conducted by reviewing the computerised hospital records of 130 patients attending The Western Eye Hospital contact lens department over the period 1st Jan 1999 to 31st Dec 1999. Data on age, gender, referral pattern, visual acuity, contact lens fitting, degree of visual success, and some information on penetrating keratoplasty were obtained.

RESULTS

16.4% of all patients attending the Contact Lens clinic had keratoconus. The mean age at referral was 28.6 years and the mean age of keratoconus during the study period was 34.9 years. There was a predominance of male patients. Optometrists formed 72.2% of the referrals, and had prescribed some form of refractive correction in 70% of patients (two-thirds contact lenses) prior to hospital assessment. Of the 130 patients seen in the department during the study period, the post-referral management included bilateral contact lens fitting for 102 patients (78.5%), monocular contact lens fitting for 24 patients (18.5%) and no intervention in four patients (3%). The types of contact lenses used included PMMA lenses (2.7%), rigid gas permeable lenses (96.1%) of the spherical, elliptical and special cone lens designs, Keratosoft or Softperm lenses (0.8%) and scleral lenses (0.4%). Eleven eyes of eight patients had received penetrating keratoplasty (PK) prior to hospital assessment, of whom seven eyes needed post-surgical contact lens fitting. The main reasons for PK were contact lens intolerance (83%), frequent contact lens displacement (8.5%) and unsatisfactory visual acuity despite good contact lens fit (8.5%). Sixty-five per cent of patients were able to wear their contact lenses for more than 12 hours a day. With contact lens wear, 87% of patients had a visual acuity of 6/9 or better and 59% of eyes had improved visual acuity of 0.6 logMAR or more.

CONCLUSION

Optometrists were the main source of referral for keratoconus patients to the Hospital Eye Service (HES). The mean age at referral was 28.6 years, with a predominance of male patients. Blurred vision formed the main presenting visual symptom on initial hospital assessment; subsequently, more than two-thirds of patients required bilateral contact lenses. Rigid gas permeable contact lenses remain the mainstay treatment for advanced keratoconus, with various designs enabling a large proportion of patients to attain improved visual acuity.

Evaluation of the energetic position of the lowest excited singlet state of beta-carotene by NEXAFS and photoemission spectroscopy

In carotenoids the lowest energetic optical transition belonging to the pi-electron system is forbidden by symmetry, therefore the energetic position of the S(1) (2(1)A(g)) level can hardly be assessed by optical spectroscopy. We introduce a novel experimental approach: For molecules with pi-electron systems the transition C1s-->2p(pi*) from inner-atomic to the lowest unoccupied molecular orbital (LUMO) appears in X-ray absorption near edge spectra (NEXAFS) as an intense, sharp peak a few eV below the carbon K-edge. Whereas the peak position reflects the energy of the first excited singlet state in relation to the ionization potential of the molecule, intensity and width of the transition depend on hybridization and bonding partners of the selected atom. Complementary information can be obtained from ultraviolet photoelectron spectroscopy (UPS): At the low binding energy site of the spectrum a peak related to the highest occupied molecular orbital (HOMO) appears. We have measured NEXAFS and UPS of beta-carotene. Based on these measurements and quantum chemical calculations the HOMO and LUMO energies can be derived.

Loss of expression of HDAC-recruiting methyl-CpG-binding domain proteins in human cancer

Dysregulation of CpG-methylation is a common feature of many human cancers and tumour suppressor genes can be silenced by hypermethylation. Recently, 2 methyl-CpG-binding domain proteins have been linked to gene inactivation by their ability to recruit co-repressors and HDAC-activity to methylated gene promoters. Here, we have analysed mRNA expression of these genes, MeCP2 and MBD2, in a wide variety of primary human tumours. In solid tumours, expression levels of MBD2 (57/71) and MeCP2 (64/71) were significantly reduced in the majority of primary tumours as detected by quantitative real-time RT-PCR. Western blot analyses of MeCP2 in matched tumour-normal samples of patients with non-small-cell lung cancer (NSCLC) indicated reduced protein in a significant percentage of patients. In acute myelogenous leukaemia (n = 26), expression levels were only slightly reduced and did not differ between samples analysed at diagnosis or at the time of relapse. In early-stage NSCLC (n = 70) expression of MeCP2 and MBD2 was significantly lower in squamous cell carcinoma than in adenocarcinoma or large cell carcinoma (P = 0.03 and P = 0.01). To further elucidate the mechanisms of gene regulation, we analysed MeCP2 and MBD2 regulation during haematopoietic differentiation. No significant changes in MeCP2 or MBD2 expression were found when NB4 cells were differentiated toward granulocytes suggesting that neither differentiation nor cell cycle status were relevant for the reduced expression of these genes in human cancer. In conclusion, the significant loss of MeCP2 and MBD2 expression in human cancers suggests a potential role of this phenomenon in the development of solid human tumours.

Absolute extreme ultraviolet yield from femtosecond-laser-excited Xe clusters

Large Xe clusters (10(5)-10(6) atoms per cluster) have been irradiated with ultrashort (50 fs) and high-intensity ( approximately 2 x 10(18) W/cm(2)) pulses from a Ti:sapphire multi-TW laser at 800 nm wavelength. Scaling and absolute yield measurements of extreme ultraviolet (EUV) emission in a wavelength range between 7 and 15 nm in combination with cluster target characterization have been used for yield optimization. Maximum emission as a function of the backing pressure and a spatial emission anisotropy covering a factor of two at optimized yields is discussed with a simple model of the source geometry and EUV-radiation absorption. Circularly polarized laser light instead of linear polarization results in a factor of 2.5 higher emission in the 11 to 15 nm wavelength range. This indicates the initial influence of optical-field ionization for the interaction parameter range used and contrasts to collisional heating that seems to influence preferentially higher ionization. Absolute emission efficiency at 13.4 nm of up to 0.5% in 2pi sr and 2.2% bandwidth has been obtained.

Binding of IRE-BP to its cognate RNA sequence: SFM studies on a universal RNA backbone for the analysis of RNA-protein interaction

We have used an RNA consisting of the potato spindle tuber viroid (PSTVd) and 240 bp of double-stranded RNA derived from the GUS gene as a backbone for scanning force microscope (SFM) studies on RNA binding proteins. The in vitro transcribed RNA forms a rod-like structure of apparent 130 nm in length with a completely base paired central part flanked by the incompletely paired viroid helix with bulges on both sides. The termini of the molecule consist of loops such that no blunt or staggered RNA ends are exposed. Suitable, asymmetrical restriction sites in the construct allow for the insertion of sequences of interest, e. g. protein binding sites. We have inserted the IRE (iron responsive element) sequence into the construct and have used in vitro transcripts to study binding of IRE-BP. Relative binding frequencies show that 70% of the protein binds to the expected site in the molecule while only a slightly enhanced binding is observed at the termini. In the GUS-PSTVd-IRE backbone, the orientation of the molecule is easily determined by IRE-BP binding. It thus provides a versatile tool to study specific as well as preferential interaction of other proteins with sequences or structures inserted into a different part of the molecule.

Relationship of c-myc and erbB oncogene family gene aberrations and other selected factors to ex vivo chemosensitivity of ovarian cancer in the modified ATP-chemosensitivity assay

A pilot study on relationships of selected molecular factors [erbB-1, erbB-2, erbB-3, and c-myc oncogene average gene copy numbers (AGCN); steroid receptors and pS2 gene expression; tumor cells' DNA values] to the ex vivo chemosensitivity of ovarian cancer in a modified adenosine triphosphate cell viability chemosensitivity assay (ATP-CVA), was performed. Despite the relatively small number of patients, numerous correlations among the factors tested were found. Nevertheless, only c-myc gene dosage positively affected ex vivo chemosensitivity of tumors tested.