Tokophobia and fear of birth: a workshop consensus statement on current issues and recommendations for future research

Objective: To discuss and develop a statement on the current state of the evidence and opinion in Fear of Childbirth (FoC) and Tokophobia (Tocophobia), and to provide recommendations. Background: A group met in 2019 to discuss the state of clinical and academic knowledge relating to FoC/Tokophobia. Five key areas were agreed as the focus of the meeting. Methods: 12 internationally acknowledged experts, in this or a closely related area (e.g. PTSD) met to discuss their understanding of the evidence for FoC/ Tokophobia and current practice. The consensus described in this paper constitutes the expression of the general opinion of the participants and does not necessarily imply unanimity. Keys points: Work focussed on tokophobia is recent and there remains a wide range of issues, which were addressed in the workshop including complexity in defining prevalence, a theoretical lack of understanding, which creates challenge for robust assessment and the identification of risk factors. An improved aetiological and developmental understanding of the tokophobia is required to underpin appropriate, effective and evidence-based interventions. Evaluation of pathways of care and relevant interventions, should be a focus of future research. Conclusion: Significant gaps remain within the FoC/tokophobia knowledge base. Further research is necessary.

The relationship between sense of coherence and post-traumatic stress: a meta-analysis

Background: Antonovsky's concept of sense of coherence (SOC) - as a global orientation reflecting an individual's feeling of confidence in both the predictability of their internal and external environment and their ability to cope with stressful and challenging situations in life - shows a negative association with symptoms of post-traumatic stress. However, single studies varying in study characteristics provide heterogeneous effect size estimations. Objective: The purpose of the current study is to investigate the relationship between SOC and post-traumatic stress disorder (PTSD) symptom severity for the first time on a meta-analytical level. Method: The random-effects meta-analysis is based on zero-order correlations (r) and consists of 47 independent samples out of 45 studies (N = 10,883). Results: After correcting for sampling error, the mean correlation between SOC and PTSD symptoms was M(r) = -.41 (excluding four outliers: -.39). However, this effect could not be generalized to all types of PTSD samples owing to substantial remaining heterogeneity. Subsequent moderator analyses investigating the influence of different SOC and PTSD measures, trauma type and duration, mean age and gender imbalances per sample did not reveal significant moderating effects. Conclusions: The meta-analysis reveals a substantial correlation between SOC and PTSD symptom severity: higher SOC levels are associated with lower symptom severity. Thus, future research should progress to the question of whether the relationship between SOC and post-traumatic stress is causal, and by which factors it is moderated. Abbreviations: CD, Cook's distance; DSM, Diagnostic and Statistical Manual of Mental Disorders; (G)RR, general (and specific) resistance resources; IES(-R), Impact of Event Scale (Revised); PDS, Posttraumatic Stress Diagnostic Scale; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PTSD, post-traumatic stress disorder; SDR, standard deleted residual; SOC, sense of coherence; SOC-R, Sense of Coherence Scale - Revised.

Establishing an International Reference Image Database for Research and Development in Medical Image Processing

Introduction: The lack of comparability of evaluation results is one of the major obstacles of research and development in Medical Image Processing (MIP). The main reason for that is the usage of different image datasets with different quality, size and Gold standard.

Objectives: Therefore, one of the goals of the Working Group on Medical Image Processing of the European Federation for Medical Informatics (EFMI WG MIP) is to develop first parts of a Reference Image Database.

Methods: Kernel of the concept is to identify highly relevant medical problems with significant potential for improvement by MIP, and then to provide respective reference datasets. The EFMI WG MIP has primarily the role of a specifying group and an information broker, while the provider user relationships are defined by bilateral co-operation or license agreements.

Results: An explorative database prototype has been implemented using the MySQL database software on the Web. Templates for provider user agreements have been worked out and already applied for own ‘pre-RID-MIP’ co-operations of the authors.

Discussion and Conclusion: First steps towards a comprehensive reference image database have been done. Issues like funding, motivation, management, provision of Gold standards and evaluation guidelines are to be solved. Due to the interest from research groups and industry the efforts will be continued.

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.

What Does Big Data Mean for Wearable Sensor Systems? Contribution of the IMIA Wearable Sensors in Healthcare WG

OBJECTIVES

The aim of this paper is to discuss how recent developments in the field of big data may potentially impact the future use of wearable sensor systems in healthcare.

METHODS

The article draws on the scientific literature to support the opinions presented by the IMIA Wearable Sensors in Healthcare Working Group.

RESULTS

The following is discussed: the potential for wearable sensors to generate big data; how complementary technologies, such as a smartphone, will augment the concept of a wearable sensor and alter the nature of the monitoring data created; how standards would enable sharing of data and advance scientific progress. Importantly, attention is drawn to statistical inference problems for which big datasets provide little assistance, or may hinder the identification of a useful solution. Finally, a discussion is presented on risks to privacy and possible negative consequences arising from intensive wearable sensor monitoring.

CONCLUSIONS

Wearable sensors systems have the potential to generate datasets which are currently beyond our capabilities to easily organize and interpret. In order to successfully utilize wearable sensor data to infer wellbeing, and enable proactive health management, standards and ontologies must be developed which allow for data to be shared between research groups and between commercial systems, promoting the integration of these data into health information systems. However, policy and regulation will be required to ensure that the detailed nature of wearable sensor data is not misused to invade privacies or prejudice against individuals.

Classification of exacerbation episodes in chronic obstructive pulmonary disease patients

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive disease affecting the airways, which constitutes a major cause of chronic morbidity and a significant economic and social burden throughout the world. Despite the fact that in COPD patients exacerbations are common acute events causing significant and often fatal worsening of symptoms, an accurate prognostication continues to be difficult.

OBJECTIVES

To build computational models capable of distinguishing between normal life days from exacerbation days in COPD patients, based on physical activity measured by accelerometers.

METHODS

We recruited 58 patients suffering from COPD and measured their physical activity with accelerometers for 10 days or more, from August 2009 to March 2010. During this period we recorded six exacerbation episodes in the patients, accounting for 37 days. We were able to analyse data for 52 patients (369 patient days), and extracted three distinct sets of features from the data, one set of basic features such as average, one set based on the frequency domain and the last exploring the cross-information among sensors pairs. These were used by three machine-learning techniques (logarithmic regression, neural networks, support vector machines) to distinguish days with exacerbation events from normal days.

RESULTS

The support vector machine classifier achieved an AUC of 90% ± 9, when supplied with a set of features resulting from sequential feature selection method. Neu- ral networks achieved an AUC of 83% ± 16 and the logarithmic regression an AUC of 67% ± 15.

CONCLUSIONS

None of the individual feature sets provided robust for reasonable classification of PA recording days. Our results indicate that this approach has the potential to extract useful information for, but are not robust enough for medical application of the system.

[Multimorbidity and successful aging: the population-based KORA-Age study]

BACKGROUND

The objective of the KORA-Age research consortium is to assess the determinants and consequences of multimorbidity in the elderly and to look into reasons for successful aging in the general public.

PATIENTS AND METHODS

In the KORA-Age cohort study 9,197 persons were included who where born in the year 1943 or before and participants of previous KORA cohort studies conducted between 1984 and 2001 (KORA: Cooperative Health Research in the Region of Augsburg). The randomized intervention study KORINNA (Coronary infarct follow-up treatment in the elderly) tested a nurse-based case management program with 338 patients with myocardial infarct and included an evaluation in health economics.

RESULTS

A total of 2,734 deaths were registered, 4,565 participants submitted a postal health status questionnaire and 4,127 participants were interviewed by telephone (response 76.2% and 68.9% respectively). A gender and age-stratified random sample of the cohort consisting of 1,079 persons took part in a physical examination (response 53.8%).

CONCLUSION

The KORA-Age consortium was able to collect data in a large population-based sample and is contributing to the understanding of multimorbidity and successful aging.

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.

Establishing an international reference image database for research and development in medical image processing

INTRODUCTION

The lack of comparability of evaluation results is one of the major obstacles of research and development in Medical Image Processing (MIP). The main reason for that is the usage of different image datasets with different quality, size and Gold standard.

OBJECTIVES

Therefore, one of the goals of the Working Group on Medical Image Processing of the European Federation for Medical Informatics (EFMI WG MIP) is to develop first parts of a Reference Image Database.

METHODS

Kernel of the concept is to identify highly relevant medical problems with significant potential for improvement by MIP, and then to provide respective reference datasets. The EFMI WG MIP has primarily the role of a specifying group and an information broker, while the provider user relationships are defined by bilateral co-operation or license agreements.

RESULTS

An explorative database prototype has been implemented using the MySQL database software on the Web. Templates for provider user agreements have been worked out and already applied for own 'pre-RID-MIP' co-operations of the authors.

DISCUSSION AND CONCLUSION

First steps towards a comprehensive reference image database have been done. Issues like funding, motivation, management, provision of Gold standards and evaluation guidelines are to be solved. Due to the interest from research groups and industry the efforts will be continued.

[Current prescription practice of CSE inhibitors at clinic discharge after acute myocardial infarct]

We investigated the use of statins in clinical practice in patients with acute myocardial infarction in Germany in 17,732 consecutively included patients of the registries MIR-1 and MITRA-1. A clinical follow-up has been performed in the MITRA-1 study after a mean period of 18 months. In total 30% of all patients with acute myocardial infarction received statins at discharge. From 1994 to 1998 the use of statins increased from 6% to 44%; however in 1998 still less than half of the patients with acute myocardial infarction received statins at discharge. In a logistic regression model, concomittant diseases as renal failure (OR 0.7), heart failure (OR 0.7) and diabetes mellitus (OR 0.9) were associated with a lower use of statins. Age > 70 years (OR 0.5) was also associated with a lower use of statins at hospital discharge. Patients with statins at discharge had a lower long-term mortality of 5.8% versus 12.9% in patients without statins. After adjustment to age and comorbidity, use of statins at discharge was associated with a borderline significant reduction of long-term mortality (multivariate OR 0.7, 95% CI 0.4-1.0). In a subgroup analysis of therapeutic benefit, measured by the "number needed to treat" (NNT), the number of patients to treat with statins to save one life, patients with cardiovascular risk factors, as heart failure (NNT 7.5), diabetes mellitus (NNT 7.8) and age > 70 years (NNT 13.8) had a larger therapeutic benefit as patients without these risk factors (NNT 345). However, these high-risk patients received less often statins than patients without risk factors (use of statins 11.8% versus 19.8%).

The teleconsultation service ENDOTEL. Implementation and first experiences

The multimedia teleconsultation service ENDOTEL launches in May 2000 with its asynchronous component. In the initial phase, three hospitals and four general practitioners use the service to consult a specialist in the domain of gastroenterology and endoscopy. By validation of the patient information, i.e. videos, voice clips, still images and text, the experts can decide the further proceeding, for example, whether a patient shall be transported to a specialized hospital or not (cost-saving). We report about the experiences during the initiation and the first months of operation.

Learning tumor diagnostics and medical image processing via the WWW--the case-based radiological textbook ODITEB

New Internet technologies offer excellent chances to build high-quality on-line learning media for the education in medicine. Especially, the teaching of diagnostics with medical imaging as well as medical image processing can be supported by the excellent visualization and interaction capabilities. In cooperation with three radiological departments at German universities in Munich, Erlangen and Würzburg, the case-based open distributed Internet text book (ODITEB) for tumor diagnosis of the GI-tract, liver, pancreas and thorax has been developed at the Institut für Medizinische Statistik und Epidemiologie (IMSE) of the Technische Universität München. It offers a big collection of clinical tumor cases located on servers at the provider sites Munich, Erlangen and Würzburg, visualization and interaction similar to a real CT or MRI console, original DICOM data, X-rays and endoscopic and endosonographic videos, and expert-guided tours through the cases. In a first evaluation in summer 1998, 32 medical students graded the application with 1.9 ('good') on a scale from 1 ('very good') to 5 ('very bad'). The textbook supports German language, an English version is in preparation. In a second part, it contains lessons in medical image processing for students of medical informatics. An ODITEB release 2 with several improvements will be finished until February 2000. The use of the textbook is free of cost.

The case-based Internet textbook ODITEB for multi-modal diagnosis of tumors--development, features and first experiences

Internet technologies offer the chance to build high-quality learning media for the education in medicine. In particular, the teaching of diagnostics with medical imaging can be supported by the excellent visualization and interaction capabilities. In cooperation with three radiological departments at German universities in Munich, Erlangen and Würzburg the distributed case-based Internet textbook ODITEB for tumor diagnosis of the GI-tract, liver, pancreas and thorax has been developed. It offers a growing collection of didactically prepared cases located on servers at the provider sites Munich, Erlangen and Würzburg, functionality similar to a real CT console, original DICOM data, X-rays and endoscopic and endosonographic videos, and expert-guided tours through the cases. In a first evaluation in summer 1998, 32 medical students graded the application with 1.9 ('good') on a scale from 1 ('very good') to 5 ('very bad').

Teleconsultation for endoscopic diagnosis of gastrointestinal diseases--concepts and architecture of the service ENDOTEL

This paper introduces ENDOTEL as a new project in telemedicine, aiming to reduce local disadvantages in medical health care in rural areas. The progressing specialization in medicine results in a concentration of experts in few medical centers and to deficits of expert knowledge in rural areas, which remain as a domain of unspecialized physicians. ENDOTEL expands the conventional synchronous telemedical communication, which usually means videoconference, by an asynchronous multimedia communication and its resulting advantages. ENDOTEL breaks up with the need that participants have to be present simultaneously.

Effect of variation in the common "a" determinant on the antigenicity of hepatitis B surface antigen

Antibody to the common "a" determinant of hepatitis B surface antigen (HBsAg) protects against infection with hepatitis B virus. A number of variant surface antigens with amino acid substitutions within the "a" determinant have been described in patients around the world. Both wild type and variant HBsAgs were expressed in the yeast Pichia pastoris and the antigens were semi-purified and quantitated. The effect on antigenicity of these changes was investigated in a quantitative fashion using four monoclonal antibodies known to bind to different epitopes within the common "a" determinant. The results suggest that amino acid substitution of T131I, K141E and G145R and insertion of 3 amino acids between residues 123 and 124 markedly affect the antigenic structure of HBsAg. These substitutions and insertions in the viral envelope may lead to evasion of the virus neutralizing antibody response and also to reduce efficiency of detection by immunoassays used for diagnosis and blood-bank screening.

Effect of variation in the common "a" determinant on the antigenicity of hepatitis B surface antigen

Antibody to the common "a" determinant of hepatitis B surface antigen (HBsAg) protects against infection with hepatitis B virus. A number of variant surface antigens with amino acid substitutions within the "a" determinant have been described in patients around the world. Both wild type and variant HBsAgs were expressed in the yeast Pichia pastoris and the antigens were semi-purified and quantitated. The effect on antigenicity of these changes was investigated in a quantitative fashion using four monoclonal antibodies known to bind to different epitopes within the common "a" determinant. The results suggest that amino acid substitution of T131I, K141E and G145R and insertion of 3 amino acids between residues 123 and 124 markedly affect the antigenic structure of HBsAg. These substitutions and insertions in the viral envelope may lead to evasion of the virus neutralizing antibody response and also to reduce efficiency of detection by immunoassays used for diagnosis and blood-bank screening.

Telemedical information systems

Telemedical information systems (TIS's) form the basis for telemedicine services as well as for health information services. This paper gives an introduction to the wide scope of TIS's and discusses examples for the different types of TIS's: patient-related TIS's, knowledge-related TIS's, and meta-TIS's. It concludes that for patient-related TIS's there is the need for a better integration of TIS's with other patient-centered information systems. For the other types of TIS's, more sophisticated retrieval techniques and better user interfaces for ordinary users are required. Furthermore, short descriptions of our own projects are given: the patient-related TIS of the project TECSAC (distributed electronic patient record for cardiology) and the domain-specific knowledge-related TIS's ODITEB (radiological Internet text-book) and ENDOTEL-EIS (endoscopy information system).

A distributed medical record on a Holter-ECG archiving and analysis system

At the Department of Cardiology of the Technical University of Munich and the Deutsches Herzzentrum München cardiac disease patients are treated in close co-operation. In order to support the collaborative treatment as well as cardiological studies a distributed medical record (DMR) has been implemented on the basis of a Holter-ECG archiving and analysis system. Architecture, experiences and major benefits of the solution are reported in the paper. Between January 1995 and December 1997 6500 Holter-ECGs have been archived and analysed. The DMR is in routine operation since January 1996 for all heart catheter patients.

Low-dose iloprost infusions compared to the standard dose in patients with peripheral arterial occlusive disease Fontaine stage IV. DAWID Study Group

BACKGROUND

Intravenous iloprost, titrated from 0.5 up to 2.0 ng/kg/min has been shown in patients with PAOD III/IV to significantly improve healing of trophic lesions, relief of rest pain, and reduce the rate of major amputation or death at 6 months as compared to placebo. The effect is considered related to improvement of the microcirculation. The aim of the present trial was to identify an optimum dose regarding treatment response and tolerability, by studying 4 doses of 25, 50, 75 and 100 micrograms iloprost daily.

PATIENTS AND METHODS

302 patients with PAOD IV were randomised via a double-blind fashion to one of the 4 doses. The primary endpoint was the responder rate at end of treatment. Responders were defined as patients with very good or good global efficacy, as judged by lesion healing and pain relief. Side effects were documented and a pre-defined benefit/risk index was calculated.

RESULTS

No dose-dependency of iloprost regarding primary or secondary endpoints was observed. The rate of responders ranged between 48.7-53.5%. Side effects, mainly related to vasodilation, increased dose-dependently (p < 0.001, chi 2-test), with a significant decrease of the benefit/risk index from 2.19 +/- 1.19 to 1.64 +/- 0.97 (p = 0.012, ANOVA). Responders had a better outcome at 6 months than non-responders (2.6 fold higher rate of major amputation or death; life table analysis).

CONCLUSIONS

It is concluded that iloprost should be titrated to the optimum rather than maximum tolerated dose, since a higher incidence of side effects not associated with an increased treatment response was observed at higher doses.

Concepts of a Web-based open distributed textbook for the multimodal diagnostics of gastrointestinal tumours with MRI, CT and video-endoscopy addressing students of medicine and students of medical informatics as two different target groups

Multimodal diagnostics of gastrointestinal tumours with MRI, CT and video-endoscopy is a rapidly changing domain. The education at our universities should overcome the obstacles of traditional learning based on paper media and oral lectures with retention rates of 10-30% only. The paper presents the objectives and the results of the design phase of the project ODITEB1-Open Distributed TExt Book, for Computer-Assisted Instruction in the domain mentioned above. The main objective is to produce an electronic interactive textbook in order to shift education to more efficient learning settings with higher retention rates. The main concepts are 1) three-layer architecture (dynamic case layer, intermediate query layer, static instruction layer) 2) case pool distribution 3) active learners experience (interactive exploration of original image data).

Maturation and secretion of a serine proteinase is associated with events of late microsporogenesis

An antiserum against meiotic proteins which bind to DNA cellulose was generated as a tool to assist the identification and purification of microsporogenesis-specific proteins. In immunoblotting experiments, this antiserum identified three meiotic proteins which are differentially expressed in anthers during microsporogenesis. One of these proteins was purified and characterized by biochemical and immunological techniques. This 82 kDa protein is synthesized as a preproprotein, acquires glycans as it moves through the endoplasmic reticulum and Golgi body, and is secreted into the anther locule. Immunocytochemical experiments demonstrate that the protein is expressed primarily in tapetal cells, and reaches peak concentrations as the microsporocytes reach the tetrad stage. Zymogram analyses and protein sequence comparisons indicate that the protein is a member of the serine proteinase family. The possible roles of the proteinase in microsporogenesis and pollen development are discussed.

Thyroid abnormalities in chronic viral hepatitis and their relationship to interferon alfa therapy

The prevalence of antithyroid peroxidase antibodies (ATPO) and/or of thyroid dysfunction was studied in 422 patients with chronic viral hepatitis C, B, and D. Baseline results were compared with those during and 6 months after interferon alfa (IFN-alpha) therapy. The overall prevalence of ATPO among untreated patients was 14.1%, with no significant differences between chronic hepatitis C, B, or D, as well as between males and females. However, high ATPO titers (> or = 18 IU/mL) clustered significantly among females (8.7% vs. 3.4%; P = .022), especially those with chronic hepatitis C (11.2% vs. 3.6%; P = .036). Before treatment, 3.7% of the patients had thyroid dysfunction, mostly hypothyroidism (3.5%), the latter increasing to 14.3% among patients with ATPO titers > or = 18 IU/mL. IFN-alpha treatment significantly increased overall thyroid dysfunction (9.7%; P = .001) and hypothyroidism (7.8%; P = .01), particularly among patients with high baseline ATPO (38.5%; P = .0002). Six months after stopping IFN-alpha treatment, the prevalence of thyroid dysfunction was 8.0%, still significantly higher than at baseline. By multivariate analysis, the only predictor positively associated with pre- or on-treatment hypothyroidism was the baseline titer of the ATPO antibodies (relative risk [RR], 3.0 and 3.8 per each log titer increase, respectively). In conclusion, patients with chronic viral hepatitis on IFN-alpha treatment exhibit an almost threefold increase of baseline thyroid dysfunction, persisting long after the end of therapy. High ATPO titers, clustering among females, particularly those with hepatitis C, represent the only predictor of pre- and on-treatment hypothyroidism by multivariate analysis. Patients with chronic viral hepatitis, especially females, should be tested for ATPO and thyroid function and monitored during and posttreatment for free thyroxin (FT4) and thyroid-stimulating hormone (TSH) levels.

Improving early recognition of malignant melanomas by digital image analysis in dermatoscopy

The malignant melanoma (MM) is the most dangerous human skin disease. The incidence increased dramatically during the last years. The only chance for the patient is an early recognition and excision of the MM. The best diagnostic method for this is skin surface microscopy or dermatoscopy. Its use, however, requires much expertise. In order to support learning and using the method, a computer-based dermatoscopy workstation is being developed. Among others, new complexity measures are used for the image analysis.

An open distributed medical image and signal data server network with World Wide Web front-end

In modern patient care and medical research diagnostic imaging from multiple modalities plays an essential role. In general these digital image data are acquired at different locations. An efficient access to the data via network is often not provided due to technical, organisational and political reasons. This article presents an approach to solve the problem by means of an open distributed data server network with Web-based front-ends and describes the prototype DACHS that has been developed at the University Hospital of the Technical University of Munich.

A hypertext information system for standard operating procedures in haematological intensive care

In times of cost reduction efforts the role of standard operating procedures for both medical and nursing procedures gets increasing importance. Such standards are necessary if the quality of patient care shall not suffer but even improve. While some sophisticated approaches are coming up with generation of clinical processes from formal protocol models in connection with documentation systems the clinical practice actually looks quite different: Paper-based "operating standards" are used in day-to-day work, if any. In this paper a simple and powerful WWW-based hypertext information system for easy provision and maintenance of nursing standards is presented.

Proteasomes (prosomes) inhibit the translation of tobacco mosaic virus RNA by preventing the formation of initiation complexes

Proteasomes (prosomes) are large multiprotein complexes. They are involved in protein degradation of ubiquitin-conjugated proteins and in the generation of MHC class I peptides. We gave further evidence that they interfere with in vitro protein synthesis. Proteasomes inhibit the translation of Tobacco mosaic virus RNA. Analysis of cell-free systems by sucrose gradient centrifugation revealed that they prevent the formation of 80S initiation complexes but not the early phase of initiation.

Clinical significance of quantitative anti-HBc IgM assay in acute and chronic HBV infection

The applicability and clinical usefulness of anti-HBc IgM quantification in acute and chronic hepatitis type B by a single run of undiluted sera is largely unknown. Serum anti-HBc IgM concentrations were measured in 153 patients with various forms of acute and chronic HBV infection by a new commercially available qualitative ELISA/2-step capture assay applying streptavidin technology. The absorbance values were expressed in anti-HBc IgM U/ml using a calibration curve produced by a series of anti-HBc IgM standards. The results were compared with those obtained with another second generation qualitative anti-HBc IgM method also in undiluted sera applying the Microparticle Enzyme Immune Assay (MEIA). In acute hepatitis B, anti-HBc IgM was always > 600 U/ml (median: > 800 U/ml) declining to median values of 135 and 85 U/ml at months 3 and 6, respectively. Values above 600 U/ml were seen in 4 out of 20 (20%) HBsAg carriers with episodes of severe HBV-induced liver damage resembling acute hepatitis B (group 2) and in 2 out of 35 (5.6%) patients with HBV induced chronic active hepatitis (group 3). Values above 100 U/ml, representing the cutoff levels for the diagnosis of acute hepatitis B in the qualitative assays, were detected in 55% (11/20) and 45.7% (16/35) of the above patients of groups 2 and 3, respectively. Anti-HBc IgM was negative or under 20 U/ml in 96.7% (29/30) of HBsAg carriers with acute or chronic liver damage unrelated to HBV (HDV, HCV or drug-induced) and in 91% (41/45) of HBsAg carriers with persistently normal ALT levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Selection of prosomes and prosomal RNA by immobilized viral RNAs

Viral messengers were used to select and purify prosomes and prosomal RNA from subribosomal fractions of HeLa cells and mouse erythroblasts. Adenovirus mRNA immobilized on oligo(dT)-cellulose and tobacco mosaic virus RNA (TMV) sedimenting in sucrose gradients associated strongly with prosomes at high salt conditions forming intermolecular RNA-RNA hybrids between prosomal RNA and viral RNA. Hybrid selection of small cytoplasmic RNAs with immobilized TMV-RNA revealed a RNA species migrating at the same position as prosomal RNA. The possible existence of a box-like sequence involved in hybridization will be discussed.

Prosomes discriminate between mRNA of adenovirus-infected and uninfected HeLa cells

Prosomes are small cytoplasmic RNP complexes associated with repressed mRNA. In in vitro translation, they discriminate between the mRNA of adenovirus-infected HeLa cells and those of uninfected cells grown under normal conditions. Prosomes as well as their RNA constituents interact much more strongly with poly(A)+ mRNA of infected cells and inhibit their translation in vitro preferentially. A possible role of prosomes in the differential regulation of translation is discussed.

Prosomes. Ubiquity and inter-species structural variation

The "prosomes", a novel type of ubiquitous ribonucleoprotein particle of extraordinary stability and of defined electron microscopical structure, have been characterized in several cell types and species. Identified as a 19 S sub-component of free mRNA-protein complexes, including globin and other repressed mRNA, in the cytoplasm of duck, mouse and HeLa cells, they were previously found to inhibit protein synthesis in vitro. In all cells studied, electron microscopy shows an identical, seemingly ring-like but rather raspberry-shaped particle of 12 nm diameter, resistant to EDTA and 1% (w/v) Sarkosyl. Two-dimensional electrophoretic analysis of prosomal proteins shows a characteristic pattern in the 19,000 to 35,000 Mr range of pI 4 to 7, with an additional 56,000 Mr component specific to avian species. The prosomes found in globin mRNA-protein complexes contain about 25 protein components, 16 of which have identical molecular weight and pI values in duck and mouse, and which are also found in the prosomes of the heterogeneous free mRNPs of HeLa cells. Seral and monoclonal antibodies raised in mice against the prosomes of duck erythroblasts cross-react with some of the proteins of the mouse and HeLa cell particles. Prosomes isolated from duck and mouse globin mRNP, both contain small cytoplasmic RNAs of 70 to 90 nucleotides, which represent about 15% of the particle mass. The molecular weight and the 3'-terminal oligonucleotide of each one of these small cytoplasmic RNAs are identical in the two animal species; fingerprints of their oligonucleotides generated by RNase T1 show that more than 80% of spots are identical. In contrast, the prosomes of HeLa cells, associated with a large population of repressed mRNA, contain at least 12 small cytoplasmic RNA species. All prosomal RNAs tested so far hybridize to mRNA. The data available indicate that prosomes constitute a novel class of ubiquitous cellular ribonucleoprotein complexes, present in the nucleus and cytoplasm that, in its structural variations shown here, reflects function and species.

Heat shock increases the synthesis of the poly(A)-binding protein in HeLa cells

When HeLa cells are shifted from 37 degrees C to 45 degrees C, the synthesis of two proteins increases. Their approximate molecular masses are 73 kDa [heat shock protein 73 (hsp73)] and 87 kDa (hsp87), respectively. One of them, the hsp73, shows a specific affinity for poly(A). This protein is identical with a protein regularly found associated with translatable mRNAs in all vertebrate cells. It is well characterized by its high affinity to the poly(A) sequence of polyribosomal mRNA, and it occurs free in cytoplasm. hsp73 and the poly(A)-binding protein have the same isoelectric point and molecular size. The peptide analysis indicates that they are identical.

Prosomes are involved in the repression of viral mRNA

Prosomes are small cytoplasmic RNP complexes. We present evidence that their RNA is a potential and selective inhibitor of viral mRNA translation while translation of normal cellular mRNA e.g. rabbit globin mRNA or HeLa cell mRNA is not affected.

Atherogenesis in experimental uremia

The development of experimental atherosclerosis was studied in subtotally nephrectomized rats which were subjected to preimmunization with horseradish peroxidase and subsequent feeding with atherogenic diet. Both in sham-operated pair-fed control animals and in uremic animals, the atherogenic diet caused hyperlipemia which was more pronounced in uremic than in control animals (control animals: triglycerides 1.11 +/- 0.04 mmol/l; cholesterol 5.82 +/- 0.21 mmol/l; uremia: triglycerides 1.33 +/- 0.06; cholesterol 10.9 +/- 0.31). An increase of cholesterol was seen both in the VLDL and in the LDL fractions. Despite more pronounced hyperlipemia, lipid concentration in the aortic wall was not increased nor were more marked histological abnormalities encountered in the aorta of uremic animals (cholesterol-fed control: cholesterol 95.4 +/- 4.4 micrograms/mg protein; phospholipids 2.42 +/- 0.9 micrograms/ml protein; cholesterol-fed uremia: cholesterol 96.8 +/- 4.9; phospholipids 2.52 +/- 0.8). The results suggest that despite hyperlipemia short-term experimental renal insufficiency does not promote atherogenesis.

Acute cardiovascular reactions after cigarette smoking

The effect of cigarette smoking on the cardiovascular system was determined in the following way: Two cigarettes of relatively high (1.54 mg) and very low (0.08 mg) nicotine content were smoked and compared to sham smoking. After inhalation under standardized conditions there was a relatively high increase of the plasma nicotine levels and a subsequent exponential decrease. Two hours after smoking the levels were still elevated. After 2 low nicotine cigarettes there was a significant small short-term increase. The changes of the pulse rate were directly related to the nicotine levels and the pulse pressure transit time from the heart to the calf and the digital blood flow was indirectly related to them. The regulation of these parameters is exactly related with the nicotine levels probably through the release of catecholamines. The cardiovascular reactions after smoking may indicate the additional myocardial work load after cigarettes of different nicotine content.

Evaluation of smoking-induced effects on sympathetic, hemodynamic and metabolic variables with respect to plasma nicotine and COHb levels

The effect of smoking cigarettes containing 1.5 mg and 0.08 mg nicotine per cigarette and of sham-smoking was studied in six healthy habitual smokers. Levels of carboxyhemoglobin (COHb) and plasma nicotine were measured simultaneously with hemodynamic variables, such as heart rate and blood pressure, and with the metabolic parameters, plasma DBH, cortisol, blood glucose, lactate and free fatty acids. All variables, with the exception of COHb are dose related to plasma nicotine levels. Blood pressure, heart rate and lactate show simultaneous peaks together with maximal nicotine levels, while DBH and cortisol, blood glucose and free fatty acids show a delayed reaction compared to nicotine concentrations. No effects of COHb, even with levels up to 5.6 +/- 0.5% have been observed on the variables investigated. These results demonstrate, that it is nicotine which induces considerable hemodynamic and metabolic alterations after smoking.