Enhancing predictability of IDH mutation status in glioma patients at initial diagnosis: a comparative analysis of radiomics from MRI, [18F]FET PET, and TSPO PET

PURPOSE

According to the World Health Organization classification for tumors of the central nervous system, mutation status of the isocitrate dehydrogenase (IDH) genes has become a major diagnostic discriminator for gliomas. Therefore, imaging-based prediction of IDH mutation status is of high interest for individual patient management. We compared and evaluated the diagnostic value of radiomics derived from dual positron emission tomography (PET) and magnetic resonance imaging (MRI) data to predict the IDH mutation status non-invasively.

METHODS

Eighty-seven glioma patients at initial diagnosis who underwent PET targeting the translocator protein (TSPO) using [18F]GE-180, dynamic amino acid PET using [18F]FET, and T1-/T2-weighted MRI scans were examined. In addition to calculating tumor-to-background ratio (TBR) images for all modalities, parametric images quantifying dynamic [18F]FET PET information were generated. Radiomic features were extracted from TBR and parametric images. The area under the receiver operating characteristic curve (AUC) was employed to assess the performance of logistic regression (LR) classifiers. To report robust estimates, nested cross-validation with five folds and 50 repeats was applied.

RESULTS

TBRGE-180 features extracted from TSPO-positive volumes had the highest predictive power among TBR images (AUC 0.88, with age as co-factor 0.94). Dynamic [18F]FET PET reached a similarly high performance (0.94, with age 0.96). The highest LR coefficients in multimodal analyses included TBRGE-180 features, parameters from kinetic and early static [18F]FET PET images, age, and the features from TBRT2 images such as the kurtosis (0.97).

CONCLUSION

The findings suggest that incorporating TBRGE-180 features along with kinetic information from dynamic [18F]FET PET, kurtosis from TBRT2, and age can yield very high predictability of IDH mutation status, thus potentially improving early patient management.

Genome-wide association study of delay discounting in Heterogenous Stock rats

Delay discounting refers to the behavioral tendency to devalue rewards as a function of their delay in receipt. Heightened delay discounting has been associated with substance use disorders, as well as multiple co-occurring psychopathologies. Genetic studies in humans and animal models have established that delay discounting is a heritable trait, but only a few specific genes have been associated with delay discounting. Here, we aimed to identify novel genetic loci associated with delay discounting through a genome-wide association study (GWAS) using Heterogenous Stock rats, a genetically diverse outbred population derived from eight inbred founder strains. We assessed delay discounting in 650 male and female rats using an adjusting amount procedure in which rats chose between smaller immediate sucrose rewards or a larger reward at variable delays. Preference switch points were calculated for each rat and both exponential and hyperbolic functions were fitted to these indifference points. Area under the curve (AUC) and the discounting parameter k of both functions were used as delay discounting measures. GWAS for AUC, exponential k, and indifference points for a short delay identified significant loci on chromosomes 20 and 14. The gene Slc35f1, which encodes a member of the solute carrier family of nucleoside sugar transporters, was the only gene within the chromosome 20 locus. That locus also contained an eQTL for Slc35f1, suggesting that heritable differences in the expression of that gene might be responsible for the association with behavior. The gene Adgrl3, which encodes a member of the latrophilin family of G-protein coupled receptors, was the only gene within the chromosome 14 locus. These findings implicate novel genes in delay discounting and highlight the need for further exploration.

Diversity Competence in Healthcare: A minimal definition

Background

Health professionals face a variety of professional challenges in today's plural societies. Sciences propose a specific skill set can help to meet those challenges. Various terms and sometimes extensive concepts are provided for diversity competence. The related learning processes are time-consuming and demanding to implement in hectic clinical realities, so that a basic, easy to deplore training package of essential skills would be desirable in order to enable health professionals to take equally good care of all patients including migrants and minorities.

Methods

A two-round Delphi study was conducted to prioritise teaching objectives; 31 clinical and academic migrant health experts from 13 European countries participated. A round of open questions was followed by a standardised rating round of 65 items. Data was descriptively analysed (m, M, SD) and consensus defined as 80% of experts assigning high importance to a competence.

Results

The process identified essential competences as well as high priority cognitive, affective and pragmatic competences, leading to a minimal definition of diversity competence for health professionals which includes respectfulness, empathy, diversity awareness and reflection, knowledge on social determinants as well as ethics and human rights; Further skills are: being able to listen, observe and communicate understandably, including professional usage of interpreters, shared decision-making and individual, need-based care.

Conclusions

The panel reached consensus on many of the competences. In general, attitudes and practical skills were considered essential. Basic trainings that meet the needs of professionals and help them cope with everyday challenges can be designed on the grounds of these findings.

We provide a working definition of ‘diversity competence of health professionals’ for scientific exchange and investigation and propose the conscious use of a ‘diversity’ instead of ‘intercultural” terminology.

Key messages

Diversity competence: what should be prioritised in an online course? An adapted delphi study

Background

Population diversity is a reality in our societies and requires health systems and health professionals to adapt to the needs of diverse patient groups, including migrants and ethnic minorities. This study aims to investigate topics and methods that should be prioritised in an online course on diversity competence in healthcare delivery to improve health care encounters and provide health services that meet the unique needs of all patients in order to reduce health disparities.

Methods

The study uses an adapted Delphi method including two rounds, combining some open-ended questions with pre-defined items, asking 31 European academic experts and health professionals within the field of migrant health to rate training content and teaching methods. Consensus for training topics was set to 80% and for teaching methods 70%.

Results

The only item reaching 100% consensus as being important or very important to include was ‘health effects of migration (pre-, mid- and post-migration risk factors)’. Other high-scoring items were ‘social determinants of health’ (97%) and ‘discrimination within the healthcare sector’ (also 97%). A general trend was to focus more on reflective practice since almost all items in the reflection section reached consensus. ‘Reflection on own stereotypes and prejudices’ reached the highest consensus in this section (97%).

Conclusions

Experts’ prioritisations of teaching content and methods for diversity training can help the design of short online trainings for health professionals and reduce extensive course content, thereby fostering professional development and enabling diversity competence trainings to be implemented in cases of scarce resources.

Key messages

• Trend toward more focus on ‘diversity’ and less focus on ‘culture, and the inclusion of social determinants of health and awareness of stereotypes and bias in training of health professionals.

• Diversity competence training should use reflective exercises and activities as teaching methods in online training.

Concept Development of an On-Chip PET System

Organs-on-Chips (OOCs), microdevices mimicking in vivo organs, find growing applications in disease modeling and drug discovery. With the increasing number of uses comes a strong demand for imaging capabilities of OOCs. Positron Emission Tomography (PET) would be ideal for OOC imaging, however, current PET systems have insufficient spatial resolution for this task. In this work, we propose the concept of an On-Chip PET system capable of imaging OOCs. Our system consists of four detectors arranged around the OOC device. Each detector is made of two monolithic Lutetium-yttrium oxyorthosilicate (LYSO) crystals and covered with Silicon photomultipliers (SiPMs) on multiple surfaces. We use a Convolutional Neural Network (CNN) trained with data from a Monte Carlo Simulation (MCS) to predict the first gamma-ray interaction position inside the detector from the light patterns that are recorded by the SiPMs on the detector's surfaces. With the Line of Responses (LORs) created by the predicted interaction positions, we reconstruct with Simultaneous Algebraic Reconstruction Technique (SART). The CNN achieves a mean average prediction error of 0.78 mm in the best configuration. We use the trained network to reconstruct an image of a grid of 21 point sources spread across the field-of-view and obtain a mean spatial resolution of 0.53 mm. We demonstrate that it is possible to achieve a spatial resolution of almost 0.5 mm in a PET system made of multiple monolithic LYSO crystals by directly predicting the scintillation position from light patterns created with SiPMs. We observe that CNNs from the ResNet family perform better than those from the EfficientNet family and that certain surfaces encode significantly more information for the scintillation-point prediction than others.

Opening up a tailored tutor qualification program for medical students to other healthcare students - a mixed-method study

BACKGROUND

Peer-led tutorials are widely used in medical education to promote practical skills acquisition and support faculty staff. Typically, student tutors are custom trained for this specific task. We investigated whether opening up an existing medical tutor qualification program to other degree programs is successful in terms of acceptance among students, acquisition of tutor-specific and interprofessional competencies, and which factors contribute to success or failure.

METHODS

We developed a two-day tutor qualification program and conducted it annually from 2016 to 2020 with medical and other healthcare students. At the end of each course, we administered a written survey in which the participants rated the following items: their attitudes towards interprofessional learning (using the UWE-IP-D Interprofessional Learning Scale), the interprofessional learning setting, the teaching approach, and their competency acquisition (each on a five-point Likert scale; 1 = strongly agree, 5 = strongly disagree). Furthermore, we assessed participants' qualitative feedback in free-text fields and performed inductive content analyses.

RESULTS

The study participation rate was high (response rate 97%; medical students: n = 75; healthcare students: n = 22). Participants stated high levels of competency acquisition (total M = 1.59, individual items' M's ranging from 1.20 to 2.05) and even higher satisfaction with the teaching approach (total M = 1.28, individual items' M's ranging from 1.43 to 1.05). Overall satisfaction with the training was M = 1.22; SD = 0.58. No significant differences in ratings were found between the student groups. The qualitative results showed that students appreciated the interprofessional setting and experienced it as enriching. The most positive feedback was found in didactics/teaching methods on role-plays and group work; most suggestions for improvement were found in the area of structure and organisation on breaks and time management.

CONCLUSIONS

Opening up an existing medical tutor qualification program to other student groups can be seen as fruitful to teach not only tutor-related aspects but also interprofessional competencies. The results demonstrate the importance of detailed planning that considers group composition and contextual conditions and provides interactive teaching methods to promote interprofessional experiences. This study offers important information about prerequisites and methodological implementation that could be important for the interprofessional redesign of existing training programs.

Housing and health: An empirical framework for refugee reception centres

Background

Housing is a key social determinant of health. Newly arriving asylum seekers and refugees (ASR) in Germany are assigned to reception centres (RC), comprising large, shared facilities in remote locations. Our aim was to explore how housing affects health from the perspective of ASR in order to develop an empirical framework for further research.

Methods

We conducted a secondary analysis of 47 qualitative interviews with ASR living in German RC and developed a multidimensional framework containing the effects of housing characteristics on health in this setting. An initial coding scheme with five dimensions was developed from the literature: material aspects, meaningful aspects, housing as an expression of socioeconomic status, community, and immediate environment. Using thematic analysis, sub-codes were generated inductively, resulting in the final framework.

Results

Important material aspects included building structure, basic amenities, sharing of living space and food provision. Among these, room sharing and food provision were particularly relevant for participants. Meaningful dimensions important for health included autonomy, privacy, safety and stability, which were limited in RC due to missing door locks, room sharing, restrictions of movement and frequent transfers between centres. Based on participants' statements, the community was divided into “outside” and “inside” the RC, which, unlike the “outside” community, have collective and organisational characteristics. We subsumed statements about distances to services and amenities into immediate environment. However, participants reported that short distances did not always guarantee access.

Conclusions

We identified important interdependent dimensions of housing which affect health and well-being among ASR and consolidated them into an empirical framework which can serve as a basis for further research, including the future development of measurement instruments to assess effects of housing on ASR health.

Key messages

ASR narratives show that housing dimensions with importance for health in reception centres have specific characteristics and are interdependent. We developed a framework which can be used for further research on the effects of housing on ASR health in this setting, including the construction of quantitative measurement instruments.

Prognostic impact of gross tumor volume during radical radiochemotherapy of locally advanced non-small cell lung cancer-results from the NCT03055715 multicenter cohort study of the Young DEGRO Trial Group

BACKGROUND

In radical radiochemotherapy (RCT) of inoperable non-small-cell lung cancer (NSCLC) typical prognostic factors include T- and N-stage, while there are still conflicting data on the prognostic relevance of gross tumor volume (GTV) and particularly its changes during RCT. The NCT03055715 study of the Young DEGRO working group of the German Society of Radiation Oncology (DEGRO) evaluated the prognostic impact of GTV and its changes during RCT.

METHODS

A total of 21 university centers for radiation oncology from five different European countries (Germany, Switzerland, Spain, Belgium, and Austria) participated in the study which evaluated n = 347 patients with confirmed (biopsy) inoperable NSCLC in UICC stage III A/B who received radical curative-intent RCT between 2010 and 2013. Patient and disease data were collected anonymously via electronic case report forms and entered into the multi-institutional RadPlanBio platform for central data analysis. GTV before RCT (initial planning CT, GTV1) and at 40-50 Gy (re-planning CT for radiation boost, GTV2) was delineated. Absolute GTV before/during RCT and relative GTV changes were correlated with overall survival as the primary endpoint. Hazard ratios (HR) of survival analysis were estimated by means of adjusted Cox regression models.

RESULTS

GTV1 was found to have a mean of 154.4 ml (95%CI: 1.5-877) and GTV2 of 106.2 ml (95% CI: 0.5-589.5), resulting in an estimated reduction of 48.2 ml (p < 0.001). Median overall survival (OS) was 18.8 months with a median of 22.1, 20.9, and 12.6 months for patients with high, intermediate, and low GTV before RT. Considering all patients, in one survival model of overall mortality, GTV2 (2.75 (1.12-6.75, p = 0.03) was found to be a stronger survival predictor than GTV1 (1.34 (0.9-2, p > 0.05). In patients with available data on both GTV1 and GTV2, absolute GTV1 before RT was not significantly associated with survival (HR 0-69, 0.32-1.49, p > 0.05) but GTV2 significantly predicted OS in a model adjusted for age, T stage, and chemotherapy, with an HR of 3.7 (1.01-13.53, p = 0.04) per 300 ml. The absolute decrease from GTV1 to GTV2 was correlated to survival, where every decrease by 50 ml reduced the HR by 0.8 (CI 0.64-0.99, p = 0.04). There was no evidence for a survival effect of the relative change between GTV1 and GTV2.

CONCLUSION

Our results indicate that independently of T stage, the re-planning GTV during RCT is a significant and superior survival predictor compared to baseline GTV before RT. Patients with a high absolute (rather than relative) change in GTV during RT show a superior survival outcome after RCT.

Restricted care for asylum seekers. An explorative study of rationing practices

Background

Access to health care for refugees in many European countries is initially restricted. In Germany, during the first 18 months after arrival, any health services except for acute needs must be requested on a case-by-case basis. As the procedures and criteria applied by medical and state actors leading to provision or denial of services are intransparent, we explored ways to study them and derived first hypothesis about resource allocation criteria to identify possible factors leading to inequities.

Methods

A mixed-method-study was carried out, including six weeks of ethnographic exploration in two refugee outpatient clinics, documention of requests, a free-listing task and 20 in-depth interviews with public administrators, health workers, and translators.

Results

Of 101 requested services, 53 % were granted, 30% denied, 37 % not answered in time. Preliminary qualitative findings show that in dealing with restrictions, medical professionals develop enabling strategies as well as anticipatory obedience, the latter based on speculations about authorities' decision criteria. The effects of observed social classification e.g. of patient's behavior or reasons for migration need further exploration. Interviews suggest that in allocation decisions of authorities, structural and political considerations such as the prospect to remain in Germany, might play a role.

Conclusions

Procedures and strategies of care provision can be explored ethnographically. We found, that in addition to medical factors, individual, formal, social, structural and political factors might play a role in distribution decisions. Continuous documentation of requests is needed to gain further insights. To ensure equal care for all refugee patients information and training of care providers and officials is necessary as well as exchange between the involved actors. The lack of transparent rationing principles opens up opportunities for discriminiation and should be reduced via open discussion.

Key messages

Decision making criteria and procedures to grant or deny medical care for asylum seekers in Germany are intransparent and have not been sufficiently studied yet. Heterogenous local implementation of legal regulations – through medical actors and state officials – can lead to health care inequities within vulnerable populations.

Caring for refugees: Training the health workforce towards structural competence and responsibility

Background

Providing high-quality health care to superdiverse populations of newly arrived refugees poses specific structural, organisational, communicative, ethical and medical challenges that medical students in Europe are often not systematically prepared for. We created a clinical elective, to enable future doctors to identify and address the needs of refugee-patients and deliver high quality care to this population.

Objectives

We provided medical, structural, administrative, communicative and socio-cultural knowledge and skills training through seminars (24 h) and field placements (2 days) in a reception centre clinic for refugees. The training aimed at stimulating a systematic professional, personal, scientific, and political reflection, to foster social accountability, and raise awareness for the special situation of vulnerable groups. The didactic concept built on multidisciplinary lectures, student centred teaching, and research-oriented learning. Mainly qualitative summative and formative evaluations were applied to improve the course and examine training outcomes.

Results

A total of 112 students completed the elective over four terms, 50 evaluated it, of which 80% considered it worthwhile. Self-reported competencies in caring for refugee patients were low at the beginning and increased after course completion. The most important learning outcomes were knowledge of the asylum-law, gaining a multi-perspective view through multiple disciplinary lenses as well as professional, ethical, interpersonal and political insights during practical experience and reflection.

Conclusions

A multidisciplinary course that combines theory, practice and reflection, can prepare students for the complex challenges medical professionals face in caring for refugees. This could help strengthen their professional role as advocates of health equity. Our innovative didactical approach, course and evaluation concept can inspire the creation and implementation of similar courses elsewhere.

Key messages

The health workforce needs training to identify, address and help compensate respective barriers to health care and foster equal opportunities to health for refugees. A multidisciplinary teaching concept, tailored to specific target groups can help make future doctors and nurses in Europe fit for their responsibility and work in plural and ever changing societies.

Health monitoring among refugees: a state-wide, cross-sectional, population-based study in Germany

Background

Health monitoring in Germany falls short on generating timely, reliable and representative data among migrants, especially transient groups such as asylum seekers and refugees (ASR). We aim to advance health monitoring approaches and obtain reliable estimates on health status and access to health services among ASR in Germany’s 3rd largest federal state.

Methods

We conducted a state-wide, cross-sectional, population-based health monitoring survey in nine languages among ASR in collective accommodation centres. Questionnaire items capturing health status, access to care and sociodemographic variables were taken from established surveys and translated using a team approach. Random sampling on the level of 1,938 accommodation centres was employed to draw a balanced sample. Multilingual field teams recruited eligible participants using a “door-to-door” approach.

Results

Fieldwork was conducted in 58 centres, obtaining a response rate of 42.2% (n = 412). Age, sex and nationality of the included sample were comparable to the population of asylum applicants in Germany. Adults reported longstanding limitations (16%), bad/very bad general health (19%), pain (25%), chronic illness (40%), and depressive (46%) and anxiety symptoms (45%). 52% utilised primary and 37% specialist care services in the previous 12 months, while reporting unmet needs for primary (31%) and specialist care (32%). Younger and male participants had above-average health status and below-average utilisation, in contrast to older and female ASR.

Conclusions

Our health monitoring survey yielded reliable estimates on health status and health care access among ASR, revealing relevant morbidities and patterns of care. Applying rigorous epidemiological methods in linguistically diverse, transient and marginalized populations is challenging, but feasible. Integration of this approach into state- and nation-wide health monitoring strategies is needed to sustain this approach as a health planning tool.

Key messages

Applying rigorous epidemiological methods in linguistically diverse, transient and marginalized populations is challenging, but feasible. Sustainable integration of multi-lingual epidemiological methods is required in state- and nation-wide health monitoring to capture health status and access to health services for ASR.

A Randomized Evaluation of a Computer-Based Nursing Documentation System

A two-month randomized, controlled trial based on 60 patients has been performed on a ward of the Department of Psychiatry at Heidelberg University Medical Center, Germany, to investigate the influence of computer-based nursing documentation on time investment for documentation, quality of documentation and user acceptance. Time measurements, questionnaires, documentation analysis and interviews were used to compare patients documented with the computer-based system (PIK group) with the control group (patients documented with the paper-based system). The results showed the advantages and disadvantages of computer-based nursing documentation. Time needed for nursing care planning was lower in the PIK group. Some formal aspects of quality were considerably better in the PIK group. On the other hand, time required for documentation of tasks and for report writing was greater in the PIK group. User acceptance increased significantly during the study. The interviews indicated a positive influence of PIK on the cooperation between nurses and physicians.

Deficits and Remedy of the Standard Random Effects Methods in Meta-analysis

The random effects model is often used in meta-analyses. A corresponding significance test based on a normal approximation has been established. Its type I error is derived in this article by theoretical considerations and computer simulations. The test can be conservative as well as unacceptably anti-conservative. The anti-conservatism increases with the increasing number of patients and the decreasing number of studies. A modification is proposed, which keeps the nominal level asymptotically as the number of patients approaches infinity. Simulations show that the modified test is often conservative, but its conservatism is small in those situations where the standard test is highly anti-conservative.

Informatics and Medicine

Objectives: To clarify challenges and research topics for informatics in health and to describe new approaches for interdisciplinary collaboration and education. Methods: Research challenges and possible solutions were elaborated by scientists of two universities using an interdisciplinary approach, in a series of meetings over several months. Results and Conclusion: In order to translate scientific results from bench to bedside and further into an evidence-based and efficient health system, intensive collaboration is needed between experts from medicine, biology, informatics, engineering, public health, as well as social and economic sciences. Research challenges can be attributed to four areas: bioinformatics and systems biology, biomedical engineering and informatics, health informatics and individual healthcare, and public health informatics. In order to bridge existing gaps between different disciplines and cultures, we suggest focusing on interdisciplinary education, taking an integrative approach and starting interdisciplinary practice at early stages of education.

* See more detailed authors´ affiliations at the end of the article.

Non-invasive imaging of implanted peritoneal carcinomatosis in mice using PET and bioluminescence imaging

BACKGROUND

Non-invasive imaging of peritoneal carcinomatosis remains challenging. The aim of this study was to compare positron emission tomography (PET) and bioluminescence imaging (BLI) for the early detection of peritoneal carcinomatosis in a mouse model.

METHODS

Female nude mice were inoculated intraperitoneally with 1×10(7) HSC45-M2-luc gastric cancer cells. The cells were stably transfected with the gene coding for firefly luciferase. Tumour development was monitored using PET and BLI and in two subgroups, on days 3 and 4 or on days 6 and 7 after tumour cell inoculation. Tumour nodules found on post mortem examination served as the reference standard for evaluating the images.

RESULTS

PET detected 58/82 lesions (sensitivity 71 %). This method detected all (100 %) nodules larger than 6 mm, 88 % of nodules in the range of >2-4 mm, and even 58 % of small nodules measuring only 1-2 mm. BLI identified a total of 40/82 lesions (sensitivity 49 %). The difference between PET and BLI was statistically significant at p < 0.05 (PET/BLI chi-square 8.2).

CONCLUSIONS

PET was more sensitive than BLI for the detection of early peritoneal carcinomatosis in our mouse model. The sensitivity of BLI largely depended on the site of the lesions in relation to the imaging device.

[[¹¹C]choline as a pharmacodynamic marker for docetaxel therapy. Response assessment in a LNCaP prostate cancer xenograft mouse model]

The AIM of this study was to determine whether [¹¹C]choline can be used for docetaxel therapy response assessment in a LNCaP-prostate cancer xenograft mouse model using [¹¹C]choline small-animal PET/CT.

ANIMALS, METHODS

The androgen-dependent human prostate cancer cell line LNCaP was implanted subcutaneously into the left flanks of 17 SCID-mice, 12.5 mg testosterone platelets were implanted in the neck wrinkle. All mice were injected 4-6 weeks after xenograft implantation with 37 MBq [¹¹C]choline via the tail vein. Dynamic imaging was performed for 60 minutes with a small-animal PET/CT scanner. After the first [¹¹C]choline PET/CT imaging 8 mice were subsequently injected intravenously with docetaxel twice (days 1 and 5) at a dose of 3 mg/kg body weight. 8 mice were treated with PBS as a control. [¹¹C]choline PET/CT imaging was performed on day 7, 14 and 21 after treatment. Image analysis was performed using tumor/muscle (T/M) ratios (ROI(T)/ROI(M) = T/M ratio).

RESULTS

All LNCaP tumours could be visualized by [¹¹C]choline PET/CT. Before treatment the mean T/M ratio was 2.0 ± 0.2 in the docetaxel-treated group and 1.9 ± 0.2 in the control group (p = 0.837). There was a reduction in the mean [¹¹C]choline uptake after docetaxel treatment of the tumours of the LNCaP cell line as early as 1 week after initiation of therapy (T/M(mean) ratio 1.5 ± 0.2 after one week, 1.3 ± 0.2 after 2 weeks and 1.4 ± 0.2 after 3 weeks). There was no decrease in [¹¹C]choline uptake in the control group.

CONCLUSION

Our results show that [¹¹C]choline has the potential for use in the early monitoring of the therapeutic effect of docetaxel in a LNCaP prostate cancer xenograft animal model.

Long‐term outcome of primary Raynaud's phenomenon and its conversion to connective tissue disease: a 12‐year retrospective patient analysis

OBJECTIVES

To determine the frequency of development of connective tissue disease (CTD) in patients considered to have idiopathic Raynaud's phenomenon (RP) > 10 years.

PATIENTS AND METHODS

Based on initial evaluation, 113 women and 29 men were divided into either 'primary RP' (n=109) or 'possible secondary RP' (n=33) groups and were re-evaluated after a median follow-up period of 12.4 years.

RESULTS

Overall 20 patients (14.1%) progressed to a definite CTD; 10 from 'primary RP' (9.2%) and 10 from possible secondary RP' (30.3%). Initial presence of antinuclear antibodies, thickening of fingers, higher age at onset of RP, and female sex seemed to be important determinants for a possible transition to a CTD.

CONCLUSION

In RP-patients, who are at risk of development of a CTD, serial clinical and laboratory controls are warranted for the decision to initiate therapy early.

Informatics and medicine--from molecules to populations

OBJECTIVES

To clarify challenges and research topics for informatics in health and to describe new approaches for interdisciplinary collaboration and education.

METHODS

Research challenges and possible solutions were elaborated by scientists of two universities using an interdisciplinary approach, in a series of meetings over several months.

RESULTS AND CONCLUSION

In order to translate scientific results from bench to bedside and further into an evidence-based and efficient health system, intensive collaboration is needed between experts from medicine, biology, informatics, engineering, public health, as well as social and economic sciences. Research challenges can be attributed to four areas: bioinformatics and systems biology, biomedical engineering and informatics, health informatics and individual healthcare, and public health informatics. In order to bridge existing gaps between different disciplines and cultures, we suggest focusing on interdisciplinary education, taking an integrative approach and starting interdisciplinary practice at early stages of education.

Prognostic relevance of increased Rac GTPase expression in prostate carcinomas

Rac proteins of the Rho-like GTPase family, including the ubiquitous Rac1, the hematopoiesis-specific Rac2, and the least-characterized Rac3 play a major role in oncogenic transformation, tumor invasion and metastasis. However, the prognostic relevance of Rac expression in human tumors has not been investigated yet. In the present study, Rac protein expression was analyzed in benign secretory epithelium, high-grade prostatic intraepithelium neoplasia (HG-PIN), and prostate carcinomas of 60 R0-resected radical prostatectomy specimens by semiquantitative immunohistochemistry. Thus, Rac proteins were significantly strongly expressed in HG-PIN (P < 0.001) and prostate carcinomas (P < 0.001) when compared with benign secretory epithelium. Accordingly, all tumor tissues analyzed by isoform-specific real-time PCR (n = 7) exhibited significantly higher RNA expression levels of Rac (i.e. sum of Rac1 and Rac3 expression levels) than the respective benign counterparts (P = 0.018) and this appeared to result mainly from increased expression of the Rac3 isoform as verified by immunoblotting. Univariate analyses showed statistically significant associations of increased Rac protein expression in prostate cancer (P = 0.045), preoperative prostate-specific antigen levels (P = 0.044), pT stage (P = 0.002), and Gleason score (P = 0.001) with decreased disease-free survival (DFS). This prognostic effect of increased protein expression of Rac remained significant even in a multivariate analysis including all these four factors (relative risk = 3.22, 95% confidence interval = 1.04-10.00; P = 0.043). In conclusion, our data suggest that increased Rac protein expression in prostate cancer relative to the corresponding benign secretory epithelium is an independent predictor of decreased DFS and appears to result mainly from increased expression of the Rac3 isoform.

Gastrointestinal transit, release and plasma pharmacokinetics of a new oral budesonide formulation

AIMS

The aims of the study were to: (1) evaluate the gastrointestinal transit, release and absorption of budesonide from tablets with a new multimatrix formulation (MMX) designed to release the drug throughout the whole colon, and (2) assess the influence of food on budesonide bioavailability.

METHODS

Two phase I studies, each comprising 12 healthy males, were performed. Gastrointestinal transit of (153)Sm-labelled tablets containing 9 mg budesonide was evaluated by means of pharmaco-scintigraphy. The effect of food was tested by comparing plasma pharmacokinetics after intake of a high fat and high calorie breakfast with fasting controls.

RESULTS

(153)Sm-labelled tablets reached the ascending colon after a mean +/- SD 9.8 +/- 6.9 h. Initial tablet disintegration was observed in the ileum in 42% and the ascending and transverse colon in 33% of subjects. Ninety-six per cent of the dose was absorbed into the systemic circulation during passage through the whole colon including the sigmoid. Food significantly decreased C(max) values from 1429 +/- 1014 to 1040 +/- 601 pg mL(-1) (P = 0.028) and AUC values from 14 814 +/- 11 254 to 13 486 +/- 9369 pg h(-1) mL(-1) (P = 0.008). Mean residence time and t(max) increased by 12-29%. There was no drug accumulation after 1 week of once daily oral administration of budesomide.

CONCLUSIONS

MMX-budesonide tablets appear suitable for targeted colonic drug delivery. Transit parameters and low systemic bioavailability warrant further studies with the new formulation.

Influence of systemic inflammation on efficiency of antiplatelet therapy in PAOD patients

Recently it was shown that inflammation adversely influences results obtained from the platelet function analyzer system, PFA-100, hypothesizing that inflammation could confound interpretation of platelet function results. We investigated the clinical relevance of these results in patients with peripheral arterial occlusive disease (PAOD), with and without signs of systemic inflammation. In 98 PAOD patients, all treated with acetyl-salicylic acid (ASA), we obtained PFA-100 values upon stimulation with epinephrine. C-reactive protein (CRP) values were investigated as indicator for systemic inflammation. Mean CRP levels were elevated in 23 patients (23%). There was no difference of mean PFA-100 results between patients with elevated CRP levels and those without. Our results indicate that the effect of ASA on platelet aggregation, as measured by the PFA-100, is not relevantly influenced in PAOD patients with elevated CRP.

The size of pancreatic pseudocyst does not influence the outcome of invasive treatments

BACKGROUND

Authors generally agree that Giant Pancreatic Pseudocysts (> 10 cm) have a lower spontaneous resolution and are more difficult to treat than smaller pancreatic pseudocysts. This study was carried out on two groups of patients with larger and smaller pancreatic pseudocysts (pancreatic pseudocysts > 10 cm versus pancreatic pseudocysts < 10 cm), and aims to establish whether the size of pancreatic pseudocysts is a factor influencing treatment outcomes.

PATIENTS AND METHODS

In a retrospective study, we examined 71 patients with pancreatic pseudocysts following an episode of acute pancreatitis, which were treated in our hospital from 1980 to 2000. Forty-one (57.5%) patients had a large pancreatic pseudocyst. Most patients underwent invasive treatments: 9 (12.6%) had percutaneous drainage, 37 (52.1%) open surgery and 13 (18.3%) endoscopic cyst gastrostomy. 12 patients (16.9%) of the 71 were cured with medical therapy alone.

RESULTS

As far as the aetiology of the pancreatitis, location and number of the cysts were concerned, no major differences emerged between the two groups, although large pancreatic pseudocysts followed more severe pancreatitis (P = 0.0005). All giant pancreatic pseudocysts required invasive treatments; 40% of the pancreatic pseudocysts < 10 cm were successfully treated with medical therapy alone. No statistical differences were found regarding hospital mortality, morbidity, recurrence rate and hospital stay among the patients treated invasively.

CONCLUSIONS

Giant pancreatic pseudocysts more often require invasive therapy due to persistent symptoms or complications. Treatment outcomes do not seem to be influenced by the size of the pancreatic pseudocysts.

[Parathyroid carcinoma: clinical aspects and therapy]

Parathyroid carcinoma is a rare entity with an 0,5-1% of incidence on primary hyperparathyroidism (HPP) in literature. The very high values of calcium and parathormone (PTH) and the clinical aspects of hypercalcemia are the characteristics findings in these patients. We present our experience on 6 pts on 153 cases with HPP treated (3,9%). The clinical and diagnostic suspects are frequently intraoperative findings and the decision making for the surgeon is not always easy (parathyroidectomy with or without hemithyroidectomy, lymphadenectomy, surgical resection of other tissues). The mortality rate is high and we have registered three deaths at 8,14 and 64 months.

Late improvement of regional wall motion after the subacute phase of myocardial infarction treated by acute PTCA in a 6-month follow-up

BACKGROUND

The aim of this follow-up study was to investigate the late effects of acute coronary angioplasty (PTCA) on regional wall motion after the subacute phase of myocardial infarction (MI).

METHODS AND RESULTS

Seventeen patients were investigated initially at a median of 11 days and again at 6 months after acute PTCA for myocardial infarction (< 8 hours after onset of symptoms) by cardiac magnetic resonance imaging. Corresponding short-axis slices encompassing the left ventricle (LV) were acquired using a standard cine MR for regional wall motion analysis and using delayed contrast enhanced magnetic resonance imaging (ceMRI) for infarct size quantification. The infarct size was similar in the subacute phase and the 6 month follow-up (20.8 and 21.9%, respectively; n.s.). Regional wall motion improved significantly in the area of hyperenhancement [percentage wall thickening (PWT) 21.9% and 37.9%, p < 0.05] in contrast to remote normal myocardium (46.4% and 38.4%; n.s.). Regional wall motion was significantly poorer in transmural compared with nontransmural MI in the subacute stage, and a late improvement could only be observed in transmural MI.

CONCLUSION

Transmural areas of hyperenhancement displayed significant late long-term improvement of regional wall motion after acute PTCA, possibly related to prolonged stunning compared with nontransmural areas.

Monitoring of antiplatelet therapy with the PFA-100 in peripheral angioplasty patients

BACKGROUND

In patients suffering from peripheral arterial occlusive disease (PAOD) the risk of restenosis after percutaneous transluminal angioplasty (PTA) might be influenced by platelet mediated factors.

OBJECTIVE

To look for a correlation between the effect of antiplatelet therapy and recurrence of disease after PTA by monitoring platelet function in 3-month intervals by the platelet function analyzer system, PFA-100, over a period of 1 year.

PATIENTS AND METHODS

A group of 98 patients (43 females, 55 males) with PAOD, treated with aspirin (n = 52), thienopyridine (n = 34) or combination therapy of both (n = 12) were followed over a period of 12 months after elective PTA of the lower extremities with regard to occurrence of restenosis or reocclusion at the site of angioplasty, to demonstrate inhibitory effects on platelets, induced by antiplatelet therapy.

RESULTS

PFA-100 proved suitable to identify 'non-responders' to antiplatelet therapy, in a 12-month follow-up period. In 'non-responders' to clopidogrel therapy, a higher incidence of restenosis or reocclusion after PTA of the lower limbs was detected compared with 'responders'.

CONCLUSION

PFA-100, upon stimulation with ADP, might predict patients under clopidogrel therapy with elevated risk for the development of complications following PTA of the lower limbs. This could offer the chance to switch to an alternative therapy or adapt the dose.

[Evaluation of myocardial perfusion reserve in patients with CAD using contrast-enhanced MRI: a comparison between semiquantitative and quantitative methods]

OBJECTIVE

Comparison between two semiquantitative methods and a quantitative evaluation of myocardial blood flow (MBF) for assessment of myocardial perfusion reserve (MPR) in patients with CAD.

MATERIAL AND METHODS

9 patients with coronary stenoses > 50 % were examined with an ECG-gated Saturation Recovery Turbo FLASH sequence by using Gd-DTPA as contrast agent (CA). The entive measurements were performed both during rest and hyperemia induced by adenosine. The up-slopes of the signal-time S(t) curves in the myocardium and left ventricular (LV) cavity were evaluated by a linear fit. MPR was calculated from the original up-slopes of the myocardial S(t) curves and from the up-slopes, which were normalized to the up-slopes of the LV S(t) curves, respectively. For quantification of MBF values, the mathematical model MMID 4 was used and MPR was evaluated from the MBF values.

RESULTS

With all tested methods, MPR was reduced in myocardial regions subtended by arteries with stenoses >/= 70 % compared with remote regions. With MMID 4 and the normalized up-slope method, differences between severe ischemic and remote regions were statistically significant.

CONCLUSION

The up-slope method with normalization and quantification with MMID 4 are more sensitive methods to differentiate between remote and ischemic myocardium than the up-slope method without normalization.

K562 erythroleukemic cells are equipped with multiple mechanisms of resistance to lysis by complement

Resistance of tumor cells to lysis by complement is generally attributed to several protective mechanisms. The relative impact of these mechanisms in the same tumor cell, however, has not been assessed yet. We have analyzed the interaction of the human erythroleukemia tumor cell line K562 with human complement. K562 cells express the membrane complement regulatory proteins CD59, CD55 and CD46. As shown here for the first time, K562 also spontaneously release the soluble regulators C1 inhibitor, factor H, and soluble CD59. Complement resistance of K562 cells is augmented upon treatment with PMA, TNF or even with sublytic complement. Unlike TNF and sublytic complement, PMA enhanced the expression of membrane-bound CD55 and CD59 and led to increased secretion of soluble CD59. In addition, we show that complement-resistant K562 cells express a membrane-associated proteolytic activity, higher than the complement-sensitive K562/S cells. Treatment of complement-resistant K562 cells with serine protease inhibitors enhance their sensitivity to complement-mediated lysis. Inhibitors of protein kinase C (PKC) also sensitize K562 cells to complement lysis, implicating PKC-mediated signaling in cell resistance to complement. Neutralization of the CD55 and CD59 but not of CD46 regulatory activity with specific antibodies significantly increases complement-mediated K562 cell lysis. Treatment of K562 cells with a mixture of inhibitory reagents results in a significant additive enhancing effect on complement-mediated lysis of K562. In conclusion, K562 cells resist a complement attack by concomitantly using multiple molecular evasion strategies. Future attempts in antibody-based tumor therapy should include strategies to interfere with those resistance mechanisms.