Definition of the Post-COVID syndrome using a symptom-based Post-COVID score in a prospective, multi-center, cross-sectoral cohort of the German National Pandemic Cohort Network (NAPKON)

PURPOSE

The objective examination of the Post-COVID syndrome (PCS) remains difficult due to heterogeneous definitions and clinical phenotypes. The aim of the study was to verify the functionality and correlates of a recently developed PCS score.

METHODS

The PCS score was applied to the prospective, multi-center cross-sectoral cohort (in- and outpatients with SARS-CoV-2 infection) of the "National Pandemic Cohort Network (NAPKON, Germany)". Symptom assessment and patient-reported outcome measure questionnaires were analyzed at 3 and 12 months (3/12MFU) after diagnosis. Scores indicative of PCS severity were compared and correlated to demographic and clinical characteristics as well as quality of life (QoL, EQ-5D-5L).

RESULTS

Six hundred three patients (mean 54.0 years, 60.6% male, 82.0% hospitalized) were included. Among those, 35.7% (215) had no and 64.3% (388) had mild, moderate, or severe PCS. PCS severity groups differed considering sex and pre-existing respiratory diseases. 3MFU PCS worsened with clinical severity of acute infection (p = .011), and number of comorbidities (p = .004). PCS severity was associated with poor QoL at the 3MFU and 12MFU (p < .001).

CONCLUSION

The PCS score correlated with patients' QoL and demonstrated to be instructive for clinical characterization and stratification across health care settings. Further studies should critically address the high prevalence, clinical relevance, and the role of comorbidities.

TRAIL REGISTRATION NUMBER

The cohort is registered at www.

CLINICALTRIALS

gov under NCT04768998.

[Learning from Errors: Qualitative Analysis of Expert Reports on Malpractice in Family Medicine]

BACKGROUND

Expert committees of the German medical associations provide a free and out-of-court evaluation of putative cases of medical malpractice. They prepare reports that contain valuable information on process steps that precede the actual treatment error. The aim of the present study was to identify and systematically categorize individual process steps in the expert reports and thus to lay the foundations for the understanding of malpractice evaluation processes.

METHODS

In this study, ten randomly selected and anonymized expert reports of the Expert Committee for Questions of Medical Liability of the District Medical Association of South Württemberg with identified GP treatment errors were evaluated, using the method of qualitative content analysis. In an iterative process, central elements of expert reports were classified into a deductively and inductively built category system.

RESULTS

Six main categories with associated subcategories were identified: 1) structural aspects of the report, 2) doctor-patient communication, 3) medical course, 4) patient's experience, 5) action by the GP team, and 6) coordinative role in the health care system. The category system showed sufficient reliability with repeated use.

CONCLUSION

This study offers an opportunity to learn from errors. The proposed system allows to structure the complexity of expert reports on GP malpractice and may thus serve as a tool in various contexts. In particular, it facilitates the preparation and comparative analysis of reports in a structured way. It could also be used in health care research as well as in education and training.

Feasibility, safety and effectiveness of prednisolone and vitamin B1, B6, and B12 in patients with post-COVID-19-syndrome (PreVitaCOV) - protocol of a randomised, double-blind, placebo-controlled multicentre trial in primary care (phase IIIb)

BACKGROUND

After infection with SARS-CoV-2 a relevant proportion of patients complains about persisting symptoms, a condition termed Post-COVID-19-syndrome (PC19S). So far, possible treatments are under investigation. Among others, neurotropic vitamins and anti-inflammatory substances are potential options. Thus, the PreVitaCOV trial aims to assess feasibility, safety, and effectiveness of treating patients in primary care with prednisolone and/or vitamin B1, B6 and B12.

METHODS

The phase IIIb, multi-centre randomised, double-blind, and placebo-controlled PreVitaCOV trial has a factorial design and is planned as a two-phase approach. The pilot phase assessed feasibility and safety and was transformed into a confirmatory phase to evaluate effectiveness since feasibility was proven. Adult patients with PC19S after a documented SARS-CoV-2 infection at least 12 weeks ago are randomly assigned to 4 parallel treatments: prednisolone 20 mg for five days followed by 5 mg for 23 days (trial drug 1), B vitamins (B1 (100 mg OD), B6 (50 mg OD), and B12 (500 µg OD)) for 28 days (trial drug 2), trial drugs 1 and 2, or placebo. The primary outcome of the pilot phase was defined as the retention rate of the first 100 patients. Values of ≥ 85% were considered as confirmation of feasibility, this criterion was even surpassed by a retention rate of 98%. After transformation, the confirmatory phase proceeds by enrolling 240 additional patients. The primary outcome for the study is the change of symptom severity from baseline to day 28 as assessed by a tailored Patient Reported Outcomes Measurement Information System (PROMIS) total score referring to five symptom domains known to be typical for PC19S (fatigue, dyspnoea, cognition, anxiety, depression). The confirmatory trial is considered positive if superiority of any treatment is demonstrated over placebo operationalised by an improvement of at least 3 points on the PROMIS total score (t-score).

DISCUSSION

The PreVitaCOV trial may contribute to the understanding of therapeutic approaches in PC19S in a primary care context.

TRIAL REGISTRATION

EudraCT: 2022-001041-20. DRKS: DRKS00029617.

CLINICALTRIALS

gov: F001AM02222_1 (registered: 05 Dec 2022).

Using elemental staining and mapping techniques for simultaneous visualization of biological structures in the nucleus by multi-channel electron microscopy

Transmission electron microscopy (TEM) has been essential in defining the structural organization of the cell due to its ability to image cell structures at molecular resolution. However, the absence of colour has made it very difficult to compare distributions and relationships of two or more types of biomolecules simultaneously if they lack clear morphological distinctions. Furthermore, single-channel information limits functional analysis, particularly in the nucleoplasm, where fibrillar material could be chromatin, RNA, or protein. Where specific stains exist to discriminate amongst these molecules, they cannot be combined because conventional TEM is a single-channel technology. A potential path around this barrier is through electron spectroscopic imaging (ESI). ESI can map distributions of chemical elements within an ultrathin section. Here we present methods to stain specific molecules with elements that ESI can visualize to enable multi-channel electron microscopy.

Why time matters when it comes to resilience: how the duration of crisis affects resilience of healthcare and public health leaders

The meaning of time, especially in crisis, where situations are likely to become even more complex, uncertain, and disruptive, is crucial. Incorporating previous research on organizational crises, organizational resilience, extreme context, and individual resilience, we know that leaders do play a crucial role when it comes to handle adversity in organizations but also that leaders might influence organizational resilience and employee resilience. Intensified by the COVID-19 pandemic, the leaders' ability to effectively deal with a critical situation becomes even more important in healthcare organizations. We argue that time is not only important when it comes to crisis management but also that it is highly significant when it comes to leaders' resilience. Considering the aspect of time implies that different temporal demands, especially regarding the persistence of adversity, require different resilience strategies applied by the leader. Therefore, we call for future research on examining how different leaders' resilience strategies (short term vs. long term) affect crisis management outcomes as well as the resilience in healthcare and public health organizations.

Patients' Experiences With Therapeutic Approaches for Post-COVID Syndrome: Results of a Crowdsourced Research Survey

Some patients develop multiple protracted sequelae after infection with SARS-CoV-2, collectively known as post-COVID syndrome or long COVID. To date, there is no evidence showing benefit of specific therapies for this condition, and patients likely resort to self-initiated therapies. We aimed to obtain information about therapies used by and needs of this population via inductive crowdsourcing research. Patients completed an online questionnaire about their symptoms and experiences with therapeutic approaches. Responses of 499 participants suggested few approaches (eg, mind-body medicine, respiratory therapy) had positive effects and showed a great need for patient-centered communication (eg, more recognition of this syndrome). Our findings can help design clinical studies and underscore the importance of the holistic approach to care provided by family medicine.

P10.01.A Reversible blood-brain barrier (BBB) disruption by Tumor Treating Fields (TTFields) in a human 3Din vitro model

Background

Drug delivery to the central nervous system (CNS) is often impeded by the restrictive nature of the blood brain barrier (BBB). Since many therapeutic molecules are not able to traverse this barrier, the development of new methods to disrupt the BBB is of paramount importance. Tumor Treating Fields (TTFields) are alternating electric fields of low intensity (1-3 V/cm) and intermediate frequency (100-300 kHz), which are approved and effective for the treatment of glioblastoma at a frequency of 200 kHz. We recently demonstrated that TTFields at lower frequencies are able to transiently induce BBB permeability in in vitro and in vivo murine models. Here, we explored whether the transient opening of the BBB by TTFields in our murine systems also translates to a human cell-based 3D model.

Material and Methods

A three-dimensional BBB model was established by co-culturing primary human brain microvascular endothelial cells (HBMVEC) on a transwell insert together with human pericytes on the bottom of a well-plate. The model was treated with TTFields at 100-300 kHz for 2496 h using the inovitro™ TTFields Lab Bench System (Novocure®). Afterwards, the cells recovered for 24-96 h. In order to analyze the effects of TTFields on barrier integrity and compromise, transendothelial electrical resistance (TEER) of the HBMVEC monolayer was measured before the start of TTFields treatment, immediately after TTFields cessation, as well as 24-96 h after TTFields treatment. Permeability of the barrier was assessed by visualizing the movement of FITC-dextran through the HBMVEC monolayer. In addition, changes in expression and localization of the tight junction protein (TJP) claudin-5 (Cl-5) after application of TTFields were analyzed by fractionated Western-blotting and immunofluorescence (IF) staining, respectively.

Results

Application of TTFields at all investigated frequencies significantly decreased TEER across the HBMVEC monolayer after as early as 24 h, with the strongest effects seen after 72 h at a TTFields frequency of 100 kHz. TTFields treatment delocalized TJP Cl5 from the cell boundaries to the cytoplasm as evidenced by Western-blots and IF stainings. Restoration of the cell barrier was already measurable as early as 24 h after TTFields cessation and a complete recovery was evident after 48 h.

Conclusion

These results in a human 3D in vitro model confirm our previous observations from mouse models that TTFields could transiently open the BBB. These fundamental pre-clinical data demonstrate the feasibility of facilitating drug delivery to the CNS via concomitant application of TTFields. This method opens up the prospect of improved drug-based treatment of devastating CNS diseases such as GBM if these results could be translated to the clinical setting in the future.

Comorbidity, life-style factors and healthcare utilization in incident chronic kidney disease: sex-specific analyses of claims data

BACKGROUND

Chronic kidney disease (CKD) is common in aging men and women. In contrast to other European countries, Germany lacks CKD registries. The aim of this study was to determine the incidence of CKD stages 2-5 in men and women in Germany. Furthermore, differences between the sexes in terms of comorbidities, potentially inappropriate medications (PIM), and healthcare utilization were examined.

METHODS

In this retrospective observational study, claims data from members of a statutory health insurance fund aged 18 years or older with incident CKD between 2011 and 2018 were analyzed. Incident CKD was defined as having two confirmed diagnoses of CKD stages 2-5 from outpatient care or one primary or secondary diagnosis from inpatient care.

RESULTS

The age- and sex-standardized incidence of all CKD stages was 945/100 000 persons between 2011 and 2018. Incident CKD, especially stages 3 and 4, occurred more frequently in women, while the incidence of stages 2 and 5 was higher in men. While women visited their GP more frequently and were prescribed PIMs more often, men were more likely to visit a nephrologist and were more often hospitalized after the incident CKD diagnosis.

CONCLUSION

More awareness needs to be raised towards the early detection of CKD and the use of PIMs, especially in women. Improved care coordination is needed to avoid an overprovision of patients with uncomplicated incident stages and ensure that patients with advanced CKD stages get timely access to specialist care.

[Point-of-care information in GP practices: Results of a survey among German GP specialists and GP trainees]

BACKGROUND

Specific questions often arise in the context of consultations regarding, for example, diagnostics and therapeutic management. This case-specific search for information is referred to as point-of-care information. In recent years, it has been influenced by an increase in digitalization and by the development of medical expert systems providing information for medical professionals. Data on the search behavior of German general practitioners (GPs) using digital media for obtaining point-of-care information have so far not been available. The aims of this study were to describe occasion-related point-of-care information as a function of the continuing education status and to identify requirements for online research platforms.

METHODS

In a cross-sectional survey, 829 GP specialists (FÄ) and 475 physicians in training (ÄiW) were invited to answer a self-developed, partially standardized questionnaire.

RESULTS

In total, 356 questionnaires were returned (response rate: 27%). Of these, 241 (68%) were answered by FÄ and 110 (31%) by ÄiW; five participants did not provide information on their specialist status. 66% of the FÄ and 89% of the ÄiW look up information every day. 46% of the FÄ and 73% of the ÄiW use their smartphone for this purpose. Both groups most often search for medical content (94%) and for information on medications (84%). Medical expert systems are more often used by ÄiW than by FÄ; 59% of the FÄ and 82% of the ÄiW are willing to pay a fee for these services. A quick overview and relevance of information were perceived as important criteria for good information sources.

DISCUSSION

German GPs frequently search for occasion-related information. There are generation-related differences regarding, among other things, the use of and the receptiveness to fee-based expert systems. The clarity of presentation and the relevance of the information provided are important requirements of effective information platforms.

CONCLUSION

The quick search for evidence-based information relevant to clinical practice presents a challenge, particularly in broad-range specialties such as general medicine. Web-based sources are becoming increasingly popular in this regard - a trend likely to intensify in future generations of physicians. This offers great potential for medical expert systems and app-based access to best-practice guidelines. These formats should be further developed in collaboration with scientific professional societies.

[Neutralizing monoclonal antibodies in COVID-19: a case series in general practice]

BACKGROUND

 Neutralizing monoclonal antibodies (mAB) against SARS-CoV-2 reduce the severity of COVID-19 in patients with risk factors. Early administration at the onset of infection is critical for their efficacy. At this early stage of the disease, family physicians are often the first help for patients and thus central to the further course of the disease. To date, however, mAB have only rarely been used in general practice. The purpose of this case series is to demonstrate that the administration of mAB is safely feasible in the primary care setting.

CASE REPORT

 We report seven cases at risk for severe COVID-19. Two of them were not vaccinated, five had drug induced immunosuppression, and one patient was at high risk because of trisomy-21. All patients were successfully treated with the mAB Sotrovimab in a GP's practice in January/ February 2022. Two patients were treated making a house call. Based on the cases, clinical information and a hands-on handling of this therapy are described.

CONCLUSIONS

 Neutralizing mAB can be administered safely and with manageable effort in primary care setting and can help prevent a severe course and hospitalization in patients with COVID-19 and risk factors.

Persisting Symptoms After COVID-19

BACKGROUND

After recovering from coronavirus disease 2019 (COVID-19), a considerable number of patients report long-term sequelae. The epidemiologic data vary widely in the studies published to date, depending on the study design and the patient cohorts analyzed. Using a population-based approach, we report symptoms and clinical characteristics following COVID-19 (long COVID), focusing on symptoms ≥ 12 weeks (post-COVID-19).

METHODS

In three German administrative districts, all adult patients with a diagnosis of COVID-19 confirmed by polymerase chain reaction (PCR) between March and September 2020 (n = 4632) were invited to complete a questionnaire. Predictors for post-COVID-19 were identified by multiple ordinal regression analysis. Study registration: DRKS00023069.

RESULTS

A total of 1459 patients were included in the study, 175 (12%) of whom had been hospitalized for treatment of the acute phase of COVID-19. The prevalence of post-COVID-19 was 72.6% (n = 127) and 46.2% (n = 588) for hospitalized and non-hospitalized patients, respectively. The most frequently occurring long-term symptoms were fatigue (41.5% of all symptoms ≥ 12 weeks, n = 297), physical exhaustion (40.8%, n = 292), difficulty in concentrating (30.6%, n = 219), and loss of the senses of taste (25.9%, n = 185) and smell (25.5%, n = 182). Quality of life was significantly impaired in patients with post-COVID-19. The strongest risk factors for post-COVID-19 were female sex, overall severity of comorbidities, and severity of acute COVID-19.

CONCLUSION

Patients who are not hospitalized also frequently experience continued symptoms following COVID-19. The heterogeneity of symptoms calls for a multi - disciplinary stepped-care approach, for which identification of patients at risk is crucial. A limitation of the study is the lack of a control group.

[The Logic Model - a rationale for an encompassing evaluation framework of the German Competence Centers for Postgraduate Medical Education in general practice]

BACKGROUND

The Competence Centers for Postgraduate Medical Education (KW) established throughout Germany represent complex programs to increase the efficiency and quality of postgraduate medical education in general practice. So-called Logic Models serve as the framework for evaluations and quality management processes of complex programs in many areas. The aim of this article is to develop such a model, using the example of the Competence Center in Baden-Württemberg (KWBW) in order to structure its complex program logic and use it as a framework for future evaluations and quality management processes.

METHODS

The adaptation of the Logic Model to the KWBW took place in an informal, nominal group process with employees and participants of the program.

RESULTS

We identified 76 core elements of the KWBW. These core elements were classified in one of the five pillars of the Logic Model (input, activity, output, outcome and impact) and categorized according to fields of action and target groups.

DISCUSSION

The Logic Model, which was developed using the KWBW as an example, identifies and structures important core elements of a complex postgraduate medical training program for the first time. It seems to be well suited for visualizing the internal logic of this complex program and the interaction of the various elements within the KWBW. It can thus be used as the basis for a comprehensive and systematic evaluation concept and for quality assurance.

CONCLUSION

The model is also a prerequisite for comparative research questions of other university programs for postgraduate medical education and thus offers an opportunity for cooperative development efforts. This article therefore contributes to promoting quality in continuing medical training.

Developing a seminar curriculum for the Competence Center for General Practice in Baden-Wuerttemberg - a progress report

Aim: The seminar program of the KWBW Verbundweiterbildungplus® is offered by the Competence Center for Postgraduate Medical Education in Baden-Württemberg (KWBW) for physicians specializing in general practice (GP trainees). Attendance is a voluntary one comprised of 48 curricular units of 45 minutes each per GP trainee. This seminar program is meant to be attended in parallel to the postgraduate medical education in clinic or practice. The intention behind this project was to develop objectives, topics and a feasible structure for a seminar curriculum while taking time and financial constraints into account. Method: The Kern cycle was applied in an open, modified nominal group consensus technique in the form of an iterative process. Participating were 17 experts from the departments of general practice at the universities in Freiburg, Heidelberg, Tuebingen and Ulm, plus a pediatrician. Results: The main objective was defined as empowering GP trainees to independently provide high-quality primary care, including in rural areas. A basic curriculum was defined based on relevant frameworks, such as the 2018 Model Regulation for Postgraduate Medical Training (Musterweiterbildungsordnung/MWBO) and the Competency-based Curriculum General Practice (KCA). Overall, the seminar curriculum has 62 basic modules with 2 curricular units each (e.g. Basic Principles of General Practice, Chest Pain, Billing) and another 58 two-unit modules on variable topics (e.g. digitalization, travel medicine) adding up to 240 (124+116) curricular units. A blueprint with a rotation schedule for all of the teaching sites in Baden-Württemberg allows regular attendance by n=400 GP trainees over a period of five years, with individual variability in terms of program length. Conclusion: The model entails a five-year, flexible program to accompany the postgraduate medical education in general practice which can also be implemented in multicenter programs and those with high enrollments. The model's focus is on acquisition of core competencies for general practice. Despite the current shift to eLearning seminars due to SARS-CoV, the program's implementation is being continued, constantly evaluated, and used to further develop the KWBW Verbundweiterbildungplus® program.

Opportunities and challenges of e-learning in vocational training in General Practice - a project report about implementing digital formats in the KWBW-Verbundweiterbildungplus

Background: The task of the Competence Centers for vocational training (KW) is to increase the attractiveness and quality of vocational (=post-graduate) training in general practice. For this purpose, they offer, among other things, a structured seminar program for post-graduate trainees in general practice (GP-trainees). During the Covid-19 pandemic the seminar program of the KWBW-Verbundweiterbildungplus® in Baden-Württemberg was converted to digital formats. The goal of the paper is to evaluate the acceptance by the GP-trainees and lecturers, to describe experiences with the conversion to e-learning and to derive recommendations with regard to the future orientation of seminar programs in post-graduate as well as continuing medical education. The implementation was based on a modified Kern-cycle and aimed at offering eight teaching units of 45 minutes each to a large number of GP-trainees. It tried to maintain the high quality of content and education as well as the interactive character of the previous seminars. For this purpose, the events were designed as synchronous webinars (six units) with asynchronous preparation and post-processing (two units) according to the flipped classroom method. The evaluation by the participating GP-trainees and lecturers was performed online using a multi-center developed and pre-piloted questionnaire. Results and discussion: N=101 GP-trainees participated in the evaluation of five individual seminar days in the second quarter of 2020 (response rate 97%). 58% (N=59) of the trainees were satisfied or very satisfied with the implementation. 82% (n=83) rated pre-tasks as helpful. 99% (n=100) would participate in an online seminar again. For 52% (n=53) of the trainees, the attitude towards e-learning had changed positively. The main advantages mentioned were no travel, save in time and costs as well as increased flexibility. The main disadvantages mentioned were less personal interaction and technical obstacles. The high acceptance of the new digital format showed the fundamental potential of e-learning in continuing medical education. The experiences can be a source of inspiration for other departments and KW. However, it also shows that important goals of KW, such as the personal interaction of the peer group, could not be achieved. In the future, it is important to develop a suitable mix of presence and digital formats with the aim to improve the attractiveness as well as sustainability of continuing medical education.

P11.28 Alteration of blood brain barrier (BBB) permeability by Tumor Treating Fields (TTFields) in vivo

BACKGROUND

Alternating electric fields with intermediate frequency (100 - 300 kHz) and low intensity (1 - 3 V/cm), known as Tumor Treating Fields (TTFields), have been established as a novel adjuvant therapy for glioblastoma (GBM) patients. The blood brain barrier (BBB) tightly controls the influx of the majority of compounds from blood to brain. Due to this regulation, the BBB may block delivery of drugs for treatment of brain tumors, in particular GBM. In this study, we investigated the influence of TTFields on BBB permeability in vivo.

MATERIAL AND METHODS

For determination of BBB permeability, rats were treated with 100 kHz TTFields for 72 h. At the end of treatment, rats were i.v. injected with Evan′s Blue (EB), which binds Albumin (~70 kDa) upon injection to the blood. EB was extracted after brain homogenization and quantified at 610 nm. In addition, cryosections of rat brains were prepared following TTFields application at 100 kHz for 72 h, and sections were stained for Claudin 5, Occludin and immunoglobulin G (IgG) to assess vessel structure. Moreover, serial dynamic contrast-enhanced DCE-MRI with Gadolinium contrast agent (Gd) was performed before and after TTFields application.

RESULTS

In vivo, the EB accumulation in the brain was significantly increased by application of TTFields to the rat head. Claudin 5 and Occludin staining was visible in vessel endothelial cells and localized at the cells’ edges in control cryosections of rat brains. In TTFields-treated rats, the vessel structure became diffuse; Claudin 5 and Occludin were delocalized and IgG was found throughout the brain tissue and not solely inside the vessels, as it is normally the case. Serial DCE-MRI demonstrated significantly increased accumulation of Gd in the brain, detected directly after 72 h of TTFields application. 96 h after end of TTFields treatment the effect on the BBB disappeared and no difference in contrast enhancement between controls and TTFields treated animals was observable.

CONCLUSION

Application of TTFields at 100 kHz could have the potential to deliver drugs to the brain, which normally are unable to cross the BBB by altering BBB integrity and permeability. Utilizing TTFields to open the BBB and its subsequent recovery, as demonstrated by the data presented herein, could lead to a clinical approach of drug delivery for treatment of malignant brain tumors and other diseases of the central nervous system. These results will be further validated in clinical trials.

Convergent evolution of a metabolic switch between aphid and caterpillar resistance in cereals

Tailoring defense responses to different attackers is important for plant performance. Plants can use secondary metabolites with dual functions in resistance and defense signaling to mount herbivore-specific responses. To date, the specificity and evolution of this mechanism are unclear. Here, we studied the functional architecture, specificity, and genetic basis of defense regulation by benzoxazinoids in cereals. We document that DIMBOA-Glc induces callose as an aphid resistance factor in wheat. O-methylation of DIMBOA-Glc to HDMBOA-Glc increases plant resistance to caterpillars but reduces callose inducibility and resistance to aphids. DIMBOA-Glc induces callose in wheat and maize, but not in Arabidopsis, while the glucosinolate 4MO-I3M does the opposite. We identify a wheat O-methyltransferase (TaBX10) that is induced by caterpillar feeding and converts DIMBOA-Glc to HDMBOA-Glc in vitro. While the core pathway of benzoxazinoid biosynthesis is conserved between wheat and maize, the wheat genome does not contain close homologs of the maize DIMBOA-Glc O-methyltransferase genes, and TaBx10 is only distantly related. Thus, the functional architecture of herbivore-specific defense regulation is similar in maize and wheat, but the regulating biosynthetic genes likely evolved separately. This study shows how two different cereal species independently achieved herbivore-specific defense activation by regulating secondary metabolite production.

Novel Tumor Pretargeting System Based on Complementary l-Configured Oligonucleotides

Unnatural mirror image l-configured oligonucleotides (L-ONs) are a convenient substance class for the application as complementary in vivo recognition system between a tumor specific antibody and a smaller radiolabeled effector molecule in pretargeting approaches. The high hybridization velocity and defined melting conditions are excellent preconditions of the L-ON based methodology. Their high metabolic stability and negligible unspecific binding to endogenous targets are superior characteristics in comparison to their d-configured analogs. In this study, a radiopharmacological evaluation of a new l-ONs based pretargeting system using the epidermal growth factor receptor (EGFR) specific antibody cetuximab (C225) as target-seeking component is presented. An optimized PEGylated 17mer-L-DNA was conjugated with p-SCN-Bn-NOTA (NOTA') to permit radiolabeling with the radionuclide ⁶⁴Cu. C225 was modified with the complementary 17mer-L-DNA (c-L-DNA) strand as well as with NOTA' for radiolabeling and use for positron emission tomography (PET). Two C225 conjugates were coupled with 1.5 and 5.0 c-L-DNA molecules, respectively. In vitro characterization was done with respect to hybridization studies, competition and saturation binding assays in EGFR expressing squamous cell carcinoma cell lines A431 and FaDu. The modified C225 derivatives exhibited high binding affinities in the low nanomolar range to the EGFR. PET and biodistribution experiments on FaDu tumor bearing mice with directly ⁶⁴Cu-labeled NOTA'₃-C225-(c-L-DNA)_1.5 conjugate revealed that a pretargeting interval of 24 h might be a good compromise between tumor accumulation, internalization, blood background, and liver uptake of the antibody. Despite internalization of the antibody in vivo pretargeting experiments showed an adequate hybridization of ⁶⁴Cu-radiolabeled NOTA'-L-DNA to the tumor located antibody and a good tumor-to-muscle ratio of about 11 resulting in a clearly visible image of the tumor after 24 h up to 72 h. Furthermore, low accumulation of radioactivity in organs responsible for metabolism and excretion was determined. The presented results indicate a high potential of complementary L-ONs for the pretargeting approach which can also be applied to therapeutic radionuclides such as ¹⁷⁷Lu, ⁹⁰Y, ¹⁸⁶Re, or ¹⁸⁸Re.

Brain-computer interfacing in amyotrophic lateral sclerosis: Implications of a resting-state EEG analysis

Despite decades of research on EEG-based brain-computer interfaces (BCIs) in patients with amyotrophic lateral sclerosis (ALS), there is still little known about how the disease affects the electromagnetic field of the brain. This may be one reason for the present failure of EEG-based BCI paradigms for completely locked-in ALS patients. In order to help understand this failure, we have recorded resting state data from six ALS patients and thirty-two healthy controls to investigate for group differences. While similar studies have been attempted in the past, none have used high-density EEG or tried to distinguish between physiological and non-physiological sources of the EEG. We find an ALS-specific global increase in gamma power (30-90 Hz) that is not specific to the motor cortex, suggesting that the mechanism behind ALS affects non-motor cortical regions even in the absence of comorbid cognitive deficits.

Malignant catarrhal fever in a Vietnamese pot-bellied pig. A potential threat to pigs in mixed-species exhibits?

Malignant catarrhal fever (MCF) represents a sporadic and often fatal disease in various ungulate species including rarely swine. A close contact between susceptible and reservoir species of ovine herpesvirus-2 (OvHV-2) is a requirement for virus transmission. As in ruminants, a rapid course of disease with lymphohistiocytic meningoencephalitis and necrotizing vasculitis in multiple organs is frequently seen in porcine MCF. This report describes a case of MCF in a Vietnamese pot-bellied pig, which was kept in a zoological exhibit with direct contact to various ruminants. It represents the first description of porcine MCF with proven natural OvHV-2 infection in Germany. OvHV-2 should be considered as cause of fatalities among swine especially in mixed-species exhibits as present in many zoological gardens. Also farm pigs kept in free ranging husbandry systems with potential contact to sheep and other ruminant species may be at risk.

Maleimido-functionalized NOTA derivatives as bifunctional chelators for site-specific radiolabeling

Two basic and simple synthetic routes for mono- and bis-maleimide bearing 1,4,7-triazacyclononane-N,N’,N’’-triacetic acid (NOTA) chelators as new bifunctional chelators are described. The syntheses are characterized by their simplicity and short reaction times, as well as practical purification methods and acceptable to very good chemical yields. The usefulness of these two synthetic pathways is demonstrated by the preparation of a set of mono- and bis-maleimide functionalized NOTA derivatives. In conclusion, these two methods can easily be expanded to the syntheses of further tailored maleimide-NOTA chelators for diverse applications.

The crystal structure of a Thermus thermophilus tRNA(Gly) acceptor stem microhelix at 1.6 Å resolution

tRNAs are aminoacylated with the correct amino acid by the cognate aminoacyl-tRNA synthetase. The tRNA/synthetase systems can be divided into two classes: class I and class II. Within class I, the tRNA identity elements that enable the specificity consist of complex sequence and structure motifs, whereas in class II the identity elements are assured by few and simple determinants, which are mostly located in the tRNA acceptor stem. The tRNA(Gly)/glycyl-tRNA-synthetase (GlyRS) system is a special case regarding evolutionary aspects. There exist two different types of GlyRS, namely an archaebacterial/human type and an eubacterial type, reflecting the evolutionary divergence within this system. We previously reported the crystal structures of an Escherichia coli and of a human tRNA(Gly) acceptor stem microhelix. Here we present the crystal structure of a thermophilic tRNA(Gly) aminoacyl stem from Thermus thermophilus at 1.6Å resolution and provide insight into the RNA geometry and hydration.

Extranodal diffuse non hodgkin lymphoma in the thigh

Diffuse large B-cell lymphoma usually starts as a rapidly growing mass in an internal lymph node and can grow in other areas such as the bone or intestines. About 1/3 of these lymphomas are confined to one part of the body when they are localized. In the case of a 78-year-old man, an extensive tumour was located on the right thigh. Biopsies of the tumour revealed diffuse proliferation of large lymphoid cells which have totally affected the normal architecture of striated muscle. The patient received multimodality treatment including chemotherapy of the CHOP regimen and adjuvant radiotherapy. Despite this being a fast growing lymphoma, about 3 out of 4 people will have no signs of disease after initial treatment, and about half of all people with this lymphoma are cured with therapy.

Fatal Cowpox Virus Infection in Captive Banded Mongooses (Mungos mungo)

Cowpox virus infections have been described in various domestic and exotic animal species. This report is the first on an outbreak of fatal generalized cowpox virus infection among captive banded mongooses ( Mungos mungo, suborder Feliformia). All animals of a colony of 8 mongooses showed a fulminant course of disease. The whole population died (n=7) or was euthanized (n=1) within 11 days. Postmortem examinations were performed on 4 animals. All animals showed extensive necrotizing inflammation of retropharyngeal lymph nodes, typical poxviral skin lesions, and multiple necrotic foci in liver and spleen. Three animals exhibited an ulcerating stomatitis. Pulmonary lesions, a common feature of fatal cowpox virus infections in other feliform species, were not obvious. Histopathologically, characteristic cytoplasmic inclusion bodies were detected in all affected organs but the spleen. Based on transmission electron microscopy and cell culture, Orthopoxvirus was identified as the etiology. The virus was further characterized by polymerase chain reaction and sequence analysis, identifying it as cowpox virus. A survey in the habitat suggests wild brown rats ( Rattus norvegicus) as the most likely source of infection.

Natural innate cytokine response to immunomodulators and adjuvants in human precision-cut lung slices

Prediction of lung innate immune responses is critical for developing new drugs. Well-established immune modulators like lipopolysaccharides (LPS) can elicit a wide range of immunological effects. They are involved in acute lung diseases such as infections or chronic airway diseases such as COPD. LPS has a strong adjuvant activity, but its pyrogenicity has precluded therapeutic use. The bacterial lipopeptide MALP-2 and its synthetic derivative BPPcysMPEG are better tolerated. We have compared the effects of LPS and BPPcysMPEG on the innate immune response in human precision-cut lung slices. Cytokine responses were quantified by ELISA, Luminex, and Meso Scale Discovery technology. The initial response to LPS and BPPcysMPEG was marked by coordinated and significant release of the mediators IL-1β, MIP-1β, and IL-10 in viable PCLS. Stimulation of lung tissue with BPPcysMPEG, however, induced a differential response. While LPS upregulated IFN-γ, BPPcysMPEG did not. This traces back to their signaling pathways via TLR4 and TLR2/6. The calculated exposure doses selected for LPS covered ranges occurring in clinical studies with human beings. Correlation of obtained data with data from human BAL fluid after segmental provocation with endotoxin showed highly comparable effects, resulting in a coefficient of correlation >0.9. Furthermore, we were interested in modulating the response to LPS. Using dexamethasone as an immunosuppressive drug for anti-inflammatory therapy, we found a significant reduction of GM-CSF, IL-1β, and IFN-γ. The PCLS-model offers the unique opportunity to test the efficacy and toxicity of biological agents intended for use by inhalation in a complex setting in humans.

Comparative X-ray structure analysis of human and Escherichia coli tRNA(Gly) acceptor stem microhelices

tRNA identity elements assure the correct aminoacylation of tRNAs by the aminoacyl-tRNA synthetases with the cognate amino acid. The tRNA(Gly)/glycyl-tRNA sythetase system is member of the so-called 'class II system' in which the tRNA determinants consist of rather simple elements. These are mostly located in the tRNA acceptor stem and in the glycine case additionally the discriminator base at position 73 is required. Within the glycine-tRNA synthetases, the archaebacterial/human and the eubacterial sytems differ with respect to their protein structures and the required tRNA identity elements, suggesting a unique evolutionary divergence. In this study, we present a comparison between the crystal structures of the eubacterial Escherichia coli and the human tRNA(Gly) acceptor stem microhelices and their surrounding hydration patterns.

Crystal structure of an Escherichia coli tRNAGly microhelix at 2.0Å resolution

tRNA identity elements determine the correct aminoacylation by the cognate aminoacyl-tRNA synthetase. In class II aminoacyl tRNA synthetase systems, tRNA specificity is assured by rather few and simple recognition elements, mostly located in the acceptor stem of the tRNA. Here we present the crystal structure of an Escherichia coli tRNA(Gly) aminoacyl stem microhelix at 2.0 A resolution. The tRNA(Gly) microhelix crystallizes in the space group P3(2)21 with the cell constants a=b=35.35 A, c=130.82 A, gamma=120 degrees . The helical parameters, solvent molecules and a potential magnesium binding site are discussed.

Superposition of a tRNASer acceptor stem microhelix into the seryl-tRNA synthetase complex

Aminoacyl-tRNA synthetases catalyze the formation of aminoacyl-tRNAs. Seryl-tRNA synthetase is a class II synthetase, which depends on rather few and simple identity elements in tRNA(Ser) to determine the amino acid specificity. tRNA(Ser) acceptor stem microhelices can be aminoacylated with serine, which makes this part of the tRNA a valuable tool for investigating the structural motifs in a tRNA(Ser)-seryl-tRNA synthetase complex. A 1.8A-resolution tRNA(Ser) acceptor stem crystal structure was superimposed to a 2.9A-resolution crystal structure of a tRNA(Ser)-seryl-tRNA synthetase complex for a visualization of the binding environment of the tRNA(Ser) microhelix.

[Microcystic adnexal carcinoma (malignant syringoma) of the nose: case report and review of the literature]

A case of Malignant Syringoma (syn. = Microcystic Adnexal Carcinoma, Sclerosing Swat Duct Carcinoma) of the nose in a 44 year old female patient is reported. The tumor had been misdiagnosed as a Rhinophyma some 20 years before and had thus been treated under cosmetic aspects. Besides the appearance, the patient did not suffer any complaints and was referred to the ENT-department of the Klinikum Hannover for cosmetic reasons. Histopathological examination after removal revealed a malignant syringoma, which, due to its extensive size and subepithelial growth pattern, made a complete ablation of the entire nose and the adjacent soft tissue of the face necessary. Pathohistologically cellular atypia, invasive growth pattern, perineural and perivascular infiltration was characteristic. Quantitative DNA anaylsis revealed a tumor with a diploid stem line and only few aneuploid cells. Malignant syringoma is a rare differential diagnosis of face skin tumors. The present case is discussed based on a review of the literature.

[Clinical use of the birth simulation program "Anapelvis 2.0" for prediction of feto-maternal disproportion]

INTRODUCTION

The birth simulation program Anapelvis 2.0 was developed to predict feto-maternal disproportion in order to avoid the unfavourable accompanying phenomena of a secondary caesarean section. -

PATIENTS AND METHODS

The system was used in 71 patients of the Women's Hospital of the University of Mannheim during the period 01. 01. 1999 to 28. 02. 2001. These women were prone to feto-maternal disproportion according to their obstetrical history or to clinical findings. They were informed about the possibility of a computed birth simulation which was carried out in accordance with a standardized scheme. -

RESULTS

87.3 % of all patients followed the suggestion of the birth simulation in their decision concerning birth planning. In 76.1 % of the evaluated cases the delivery process was correctly predicted. -

DISCUSSION

Even though the computed birth simulation has not yet been finally evaluated, it represents a source of important information for birth planning which numerous patients appreciate. It is essential for the acceptance and validity of the procedure to inform the patient comprehensively and to generate exact pelvimetric and fetometric data.

Carrier-mediated transport of riboflavin in Ashbya gossypii

The filamentous hemiascomycete Ashbya gossypii is used for industrial riboflavin production. We examined riboflavin uptake and excretion at the plasma membrane using riboflavin auxotrophic and overproducing mutants. The riboflavin uptake system had low activity [Vmax = 20 +/- 4 nmol min(-1) g(-1) mycelial dry weight (dw)] and high affinity (KM = 40 +/- 12 microM). Inhibitor studies with the analogs FMN and FAD revealed high specificity of the uptake system. Excretion of riboflavin was not the consequence of non-specific permeability of the plasma membrane. Excretion rates in the mid-production phase were determined to be 2.5 nmol min(-1) g(-1) dw for wild-type cells and 66.7 nmol min(-1) g(-1) dw for an overproducing mutant, respectively. Inhibition of the reverse reaction, riboflavin uptake, led to an increase in apparent riboflavin efflux in the early production phase, indicating the presence of a separate excretion carrier. Riboflavin accumulation in A. gossypii vacuoles leading to product retention was found to be a secondary transport process. To address the question of whether a flux from the vacuoles back into the cytoplasm is present, we characterized efflux in hyphae in which the plasma membrane was permeabilized with digitonin. Efflux kinetics across the vacuolar membrane were unaffected by the lack of vacuolar H+ATPase activity and ATP, suggesting a passive mechanism. Based on the characterization of riboflavin transport processes in this study, the design of new production strains with improved riboflavin excretion may be possible.

De novo formation of an aneurysm in a case of unusual intracranial fibromuscular dysplasia

Intracranial fibromuscular dysplasia (FMD) is a vascular disease of unknown origin occurring predominantly in young women. The internal carotid artery is most often involved, but other cerebral arteries may also be affected. We report the case of a young woman presenting with an unusual angiographic appearance of intracranial FMD of the internal carotid artery (ICA) that could not be categorized into any type of the Osborn-Anderson classification. During follow up the patient presented with an intracerebral and subarachnoid hemorrhage. Repeated angiography revealed multiple aneurysms in the pathologic segment of the vessel. The patient underwent surgical treatment with clipping of the aneurysms, wrapping of the pathologic segment of the ICA and biopsy of the superficial temporal artery. Histopathological sections revealed FMD of the intimal type. alpha(1)-antitrypsin blood levels were normal. Cases of intracranial FMD previously reported in the literature are reviewed and various aspects of this rare disease are discussed.

Physiological consequence of disruption of the VMA1 gene in the riboflavin overproducer Ashbya gossypii

The vacuolar ATPase subunit A structural gene VMA1 of the biotechnologically important riboflavin overproducer Ashbya gossypii was cloned and disrupted to prevent riboflavin retention in the vacuolar compartment and to redirect the riboflavin flux into the medium. Cloning was achieved by polymerase chain reaction using oligonucleotide primers derived form conserved sequences of the Vma1 proteins from yeast and filamentous fungi. The deduced polypeptide comprises 617 amino acids with a calculated molecular mass of 67.8 kDa. The deduced amino acid sequence is highly similar to that of the catalytic subunits of Saccharomyces cerevisiae (67 kDa), Candida tropicalis (67 kDa), and Neurospora crassa (67 kDa) with 89, 87, and 60% identity, respectively, and shows about 25% identity to the beta-subunit of the FoF1-ATPase of S. cerevisiae and Schizosaccharomyces pombe. In contrast to S. cerevisiae, however, where disruption of the VMA1 gene was conditionally lethal, and to N. crassa, where viable disruptants could not be isolated, disruption of the VMA1 gene in A. gossypii did not cause a lethal phenotype. Disruption of the AgVMA1 gene led to complete excretion of riboflavin into the medium instead of retention in the vacuolar compartment, as observed in the wild type.

Preliminary characterization by X-ray diffraction and Raman spectroscopy of a crystalline complex of Bacillus stearothermophilus initiation factor 2 C-domain and fMet-tRNAfMet

Bacillus stearothermophilus translation initiation factor 2 (IF2) specifically binds initiator fMet-tRNAfMet and positions it into the ribosomal peptidyl site in the course of the initiation of protein biosynthesis. The isolated C-terminal domain of IF2 is capable of binding fMet-tRNAfMet, as shown by RNase A and hydrolysis protection experiments. In the presence of fMet-tRNAfMet, the IF2 C-domain yielded orthorhombic crystals of space group I222 (I212121) diffracting to 3.4 A resolution. The existence of equimolar amounts of tRNA and protein in the crystals was proven by Raman spectroscopy. The observed unit cell suggests the presence of two IF2 C- domain-fMet-tRNAfMet complexes per asymmetric unit of the crystal.

Crystallization and X-ray diffraction data of a tRNASec acceptor-stem helix

tRNASec is a UGA suppressor tRNA which co-translationally inserts selenocysteine into proteins. Its eight-base-pair tRNASec acceptor stem, which contains key recognition elements, was synthesized using solid-phase phosphoramidite RNA chemistry. High-resolution X-ray diffraction data were collected using synchrotron radiation under cryogenic cooling conditions. The crystals diffract to a maximal resolution of 1.8 A. X-ray diffraction data were processed to 2.4 A. tRNASec microhelix crystallizes in space group R32, with cell constants a = 47.02, b = 47.02, c = 373.03 A, alpha = beta = 90, gamma = 120 degrees. The crystals contain three RNA molecules per asymmetric unit.

Organelle purification and selective permeabilisation of the plasma membrane: two different approaches to study vacuoles of the filamentous fungus Ashbya gossypii

Two different approaches to prepare and characterise vacuoles from the filamentous fungus Ashbya gossypii are described, i.e. the isolation of vacuoles from hyphal cells and the controlled permeabilisation of the plasma membrane. By mechanical lysis of protoplasts and separation of the organelles on a stepped density gradient, we obtained a vacuolar fraction virtually free of contamination by other organelles, unlysed protoplasts and cell debris. The integrity of the isolated organelles was characterised by vital-staining, the presence of alpha-mannosidase, and retained accumulation of basic amino acids. In a second approach, the cell membrane of the fungus was selectively permeabilised by use of the saponin digitonin leaving the vacuoles in their physiological surrounding, i.e. protected by the rigid cell wall. The permeabilisation was monitored by the latency of predominantly cytosolic amino acids and the ATP status of the cells. Functional intactness of the vacuoles within the permeabilised hyphae was demonstrated by maintenance of the pH gradient across the vacuolar membrane as detected by accumulation of the fluorescent dye, Acridine orange. These two methods are well-suited tools for the in situ assay of intracellular compartmentation of metabolites, for vacuolar transmembrane fluxes in Ashbya gossypii, as well as for the direct access to vacuolar membranes and enzymes of this fungus.

Effects of fluoroquinolones and magnesium deficiency in murine limb bud cultures

Quinolone-induced arthropathy is probably caused by a lack of functionally available magnesium in immature joint cartilage. We used an in vitro assay to study the effects of fluoroquinolones on cartilage formation in mouse limb buds from 12-day-old mouse embryos in regular and in magnesium-deficient medium. Omission of magnesium from the medium had no adverse effect on the outcome of the culture: limb buds grew and differentiated well in regular and in magnesium-deficient Bigger's medium. Lack of calcium, however, severely impaired the development of the explants; this result was even more enhanced when both minerals (magnesium and calcium) were omitted. Electron microscopy revealed cell necrosis and deposition of electron-dense material in the vicinity of chondrocytes from limb buds after 6 days in a magnesium-free medium. A series of seven fluoroquinolones was tested at 30, 60, and 100 mg/l medium. At a concentration of 30 mg/l sparfloxacin only had a slight effect on limb development. At concentrations of 60 and 100 mg/l sparfloxacin, temafloxacin and ciprofloxacin impaired limb development in vitro concentration-dependently. The effects were enhanced in a magnesium-deficient medium (concentration of magnesium <10 micromol/l). Fleroxacin, lomefloxacin and ofloxacin impaired limb development only slightly; no significant differences were recognizable between the outcome in regular and in magnesium-deficient medium. Pefloxacin did not show any effect on limb development in both media. Using electron microscopy, very similar alterations as described above for the limbs cultured in magnesium-deficient medium were observed with ofloxacin at a concentration of 30 mg/l, which had no effect on the growth of the explants when evaluated macroscopically. The affinity of six fluoroquinolones to magnesium was determined by the use of a fluorescence assay. The affinity to magnesium correlated with the activity of the drugs in the limb bud assay. We conclude that fluoroquinolones have no effect on murine limb development in vitro at concentrations that are achieved under therapeutic conditions (peak concentrations approx. 1-5 mg/l in plasma). Effects at higher concentrations (60 and 100 mg/l) are slightly enhanced (factor 2) if the magnesium concentration in the medium is low. Macroscopically, limbs develop regularly in a magnesium-free medium, but ultrastructurally typical alterations are exhibited (e.g. cell necrosis and pericellular deposition of electron-dense material).

Chondrotoxicity and toxicokinetics of sparfloxacin in juvenile rats

Sparfloxacin is a fluoroquinolone with improved antibacterial activity against gram-positive pathogens. Like other quinolones, use of this drug is contraindicated in children and adolescents because of its potential chondrotoxicity in juveniles. We performed histological and immunohistochemical studies on the knee joint cartilage in 5-week-old rats after treatment with 600 or 1,800 mg of sparfloxacin/kg of body weight. Treatment with single or multiple oral doses of 600 mg of sparfloxacin/kg was not sufficient to induce joint cartilage lesions. However, five of eight rats treated with a single oral dose of 1,800 mg of sparfloxacin/kg of body weight showed typical cartilage lesions in the femoral part of the knee joint. The concentrations of the drug in plasma measured 0.25, 0.75, 1.5, 3, 6, 12, and 24 h after the administration of an oral dose of 600 mg of sparfloxacin/kg were 6.3 +/- 1.8, 9.2 +/- 1.7, 9.6 +/- 2.7, 13.0 +/- 1.8, 12.3 +/- 1.6, 3.4 +/- 0.4, and 0.30 +/- 0.20 mg/liter, respectively (mean +/- standard deviation [SD]; n = 5 to 6 per group). The concentrations in plasma measured 0.75, 1.5, 3, 6, 24, and 48 h after the administration of an oral dose of 1,800 mg of sparfloxacin/kg were 10.9 +/- 1.5, 15.9 +/- 1.6, 19.1 +/- 1.7, 14.9 +/- 3.1, 4.1 +/- 0.6, and 0.46 +/- 0.37 mg/liter, respectively (mean +/- SD; n = 3 to 4 per group). The concentrations of sparfloxacin in joint cartilage were significantly higher at all time points studied (114.8 +/- 80, 99.4 +/- 31.5, 84.9 +/- 16.8, 44.4 +/- 13.9, and 14.2 +/- 4.8 mg of sparfloxacin/kg at 1.5, 3, 6, 24, and 48 h after the administration of 1,800 mg/kg, respectively). The range of concentrations in bone were similar to the range of concentrations in cartilage (peak, 115 +/- 12 mg/kg after 3 h). Our data indicate that chondrotoxic doses of sparfloxacin in juvenile rats are approximately 300 times higher than the doses of sparfloxacin used therapeutically (1,800 versus approximately 6 mg/kg of body weight), but due to species differences in kinetics, concentrations in plasma differ by a factor of only approximately 15. More data on quinolone concentrations in cartilage from animals and humans could provide a better basis for a reasonable risk assessment.