Linking patient-centered communication with cancer information avoidance: The mediating roles of patient trust and literacy

OBJECTIVES

This study, drawing on the pathway mediation model developed by Street and his colleagues (2009) that links communication to health outcomes, explores how patient-centered communication affects cancer information avoidance.

METHODS

Data was gathered through online access panel surveys, utilizing stratified sampling across Germany, Switzerland, the Netherlands, and Austria. The final sample included 4910 non-cancer and 414 cancer patients, all receiving healthcare from clinicians within the past year.

RESULTS

The results demonstrated that patient-centered communication is directly associated with reduced cancer information avoidance, especially among cancer patients. Additionally, this association is indirectly mediated through patient trust and healthcare literacy.

CONCLUSION

The findings provide empirical evidence that reveals the underlying mechanism linking clinician-patient communication to patient health information behavior.

PRACTICE IMPLICATIONS

The potential of clinician-patient communication in addressing health information avoidance is highlighted by these findings. Future interventions in healthcare settings should consider adopting patient-centered communication strategies. Additionally, improving patient trust and literacy levels could be effective in reducing cancer information avoidance.

Clarifying the Relationship Between Information Seeking and Avoidance: Longitudinal Analyses of Information Behaviors and Their Normative Influences

Information seeking and avoidance are relevant behaviors to cope with health crises. While there are various assumptions about their relationship, past research has not yet analyzed their interplay. The present study aims to clarify the relationship between information seeking and avoidance in the course of the COVID-19 pandemic and shed light on whether both behaviors are impacted by seeking- and avoidance-related norms, which are known factors in individuals' health- and risk-related behaviors. Based on a four-wave panel study conducted among German residents (n = 492), we investigated information seeking and avoidance and their normative influences from a longitudinal perspective. Results of random intercept cross-lagged panel models suggest that information seeking and avoidance are distinct, not causally related but correlated concepts. This understanding is supported by the findings that seeking- and avoidance-related norms operate differently for seeking and avoidance. The results add to construct clarification and theory development, but more research is needed to understand the relations between information behaviors.

Search Engine Use for Health-Related Purposes: Behavioral Data on Online Health Information-Seeking in Germany

Internet searches for health-related purposes are common, with search engines like Google being the most popular starting point. However, results on the popularity of health information-seeking behaviors are based on self-report data, often criticized for suffering from incomplete recall, overreporting, and low reliability. Therefore, the current study builds on user-centric tracking of Internet use to reveal how individuals actually behave online. We conducted a secondary analysis of passively recorded Internet use logs to examine the prevalence of health-related search engine use, the types of health information searched for, and the sources visited after the searches. The analysis revealed two key findings. 1) We largely support earlier survey-based findings on the prevalence of online health information seeking with search engines and the relatively minor differences in information-seeking behaviors between socio-demographic groups. 2) We provide a more granular picture of the process of HISB using search engines by identifying different selection patterns depending on the scope of the searches.

Health Information as "Fodder for Fears": A Qualitative Analysis of Types and Determinants of the Nonuse of Health Information

As not all individuals are willing to pay attention to health information it is crucial to understand and distinguish the underlying motives and the scope of various nonuse behaviors. To increase conceptual clarity and specify theoretical assumptions about the types of nonuse of health information and their determinants, we used a qualitative research approach. Semi-structured interviews with 11 female, 10 male, and 10 non-binary participants aged between 18 and 67 (M = 39.7) showed that information ignoring and avoidance are two distinct behaviors characterized by their motivational patterns. Information ignoring is a preference for other content, serving as a strategy to manage limited time resources and receptivity. Information avoidance is understood as a decision to avoid threatening health information serving emotion regulation. Our data further indicate that information ignoring and avoidance are not unidimensional constructs. Instead, the selectivity and consistency of both behaviors build various types of information ignoring and avoidance, which need to be explained differently considering individual differences, cognitive, affective, socio-normative, and structural factors. Further, theory specification should build on the revealed findings and test which factors relate to which kind of nonuse behaviors.

Public controversy and citizens' attitude formation about animal research: A case for scholarship and recommendations on conflicts at the science-society interface

Activist groups attack animal research and put scientists and their institutions under pressure, whereas scientists often remain silent. We report an interdisciplinary research project driven by a communication science perspective on how citizens respond to news reports about animal research (3 experiments, overall N = 765) and a German science-initiated information platform ("Tierversuche verstehen"; controlled user study, N = 100). Findings demonstrate that a critical journalist perspective within neutral, two-sided news reports (e.g., skeptical expert statements or images of suffering animals) does not affect citizen opinion strongly. Information media provided by scientific institutions seem to be welcomed even by citizens who hold critical prior attitudes. From these results, we develop a set of recommendations for future public communication of animal research that builds on best practices in organizational and crisis communication. These suggestions are intended to empower animal researchers to actively participate in public debate to support citizens' informed attitude formation.

Avoidance of Interpersonal Discussions About the COVID-19 Vaccination: Applying the Theory of Motivated Information Management

Using a stratified sample of German non-vaccinated residents (N = 1,328), we examined the effectiveness of the Theory of Motivated Information Management (TMIM) in explaining avoidant information management among family and friends, in the context of the COVID-19 vaccination. Our results generally supported the TMIM's utility as a theoretical framework for understanding avoidant information management, as the model fitted the data well. The study contributes to the theoretical development of the TMIM, by proving that anxiety and hope operate jointly and contribute to decisions for avoiding interpersonal discussions. Further, our findings indicate that avoidance efficacy is a valuable supplement to the considered types of efficacy assessments. As a practical implication, our findings indicate that interventions encouraging individuals to talk to their family and friends should focus on raising levels of communication and target efficacy, to overcome barriers to interpersonal discussions. This is significant in motivating individuals to get vaccinated.

The Planned Risk Information Seeking Model Applied to Vaccine Information Avoidance and the Role of Affect, Emotion and Perceived Benefits

Using a stratified sample of German residents (N = 1,508), we examined intentions to avoid information about vaccination against COVID-19. The study was guided by the planned risk information seeking model (PRISM), also taking into consideration benefit perceptions, positive affective responses, and discrete emotions. Our findings generally supported the utility of the extended PRISM to predict information avoidance intentions; most of the hypothesized relationships were supported and the model accounted for 58.8% of the variance in intentions to avoid information about COVID-19 vaccination. Furthermore, perceived benefits of vaccination, and positive affect felt toward vaccination played significant roles in explaining intentions to avoid information about vaccination. A more nuanced view on affective predictors showed that hope and interest were weakly associated with less pronounced avoidance intent, whereas we found no link between avoidance intent and fear, anxiety, and anger.

Outcomes of Information Seeking and Avoidance Behaviors: Insights from a German Longitudinal Study

Examining information behaviors is often justified by their consequences but theoretical models of information behaviors have focused on antecedents of seeking and avoidance rather than their outcomes. Therefore, the current study aims to explore the affective, cognitive, and behavioral consequences of information-seeking and avoidance behaviors related to the COVID-19 pandemic. Based on a secondary analysis of a four-wave online survey of a sample of German residents (n = 492), we conducted hybrid models allowing us to differentiate between within-person effects of information behaviors on the outcomes and between-person correlations between information behaviors and outcomes. The findings revealed only single and small effects of information behaviors. Cognitive consequences such as risk perceptions were influenced by information seeking, whereas information seeking and avoidance affected individuals' subjective but not their objective level of knowledge. Neither information seeking nor avoidance impacted affective responses or a variety of behavioral consequences. These results contrast with assumptions that information seeking is per se a desirable health outcome, whereas information avoidance might be a barrier to health prevention and pandemic containment. At least in times of a health crisis, the findings suggest that information behavior might not be the central determinant of various affective, cognitive, and behavioral outcomes.

[A gendered perspective of information behaviors, its drivers, and barriers : Results of an online survey of a sample stratified for the German population]

BACKGROUND

The gender perspective is an essential level of effective health communication approaches. Against the background of the gender perspective as an essential level of effective health communication approaches, we focus on health-related information behaviors. Complementary to information seeking, information avoidance is included. Both forms of information behavior are described in gender-specific ways, and their predictors are identified using a resource-centered approach covering the individual's health, empowerment, involvement, and social support.

METHOD

An online survey of a sample stratified for the German population (N = 3000) was conducted. The two modes of information behavior as well as their theoretically derived predictors were assessed. In addition to descriptive analyses, blockwise regression analyses were used to identify gender-specific predictors of information seeking and avoidance.

RESULTS

Information seeking occurs more frequently than information avoidance. Both differ only slightly between men and women and showed the strongest correlations with the respondents' involvement. For information seeking, coping resources are also a significant predictor, while information avoidance is associated with psychological well-being and social support. Similar patterns of association emerge across genders.

CONCLUSION

Across genders, it is evident that health communication measures should strengthen the involvement of the population and their coping resources to promote information seeking and counteract information avoidance. Additionally, the findings revealed that avoiders should be more focused as one of the main target groups of health communication.

Health Information Repertoires of Implant Patients: Toward a Deeper Understanding of Multiple Source Use and the Role of Health-Related Motives

Health information-seeking behavior can be understood as an active and purposeful acquisition of information from selected information sources. It supports patients to cope with medical and health-related uncertainties and enables them to engage in informed decision-making. To obtain health information, patients can turn to a variety of sources, such as going to a physician, exchanging information with their family, or using different Internet sources. Research showed that patients typically use multiple sources to meet their health-related information needs. To attain a holistic and differentiated picture of patients' actual health information behavior, the current study draws on the repertoire approach. We conducted an online survey with 1,105 implant patients and performed a cluster analysis to explore their health information repertoires. To gain a deeper understanding of the practical meaning behind the repertoires, we also considered health-related information motives and socio-structural factors, as well as the implant type (dental, orthopedic, cochlear), to characterize the repertoires. The study revealed seven different health information repertoires of implant patients, varying in their combination of multiple sources used. In addition, group comparisons showed that the repertoires differ significantly regarding socio-structural factors, such as gender, age, and education, as well as implant type. Furthermore, information motives contribute significantly to the differentiation of the repertoires. The results are of high theoretical potential for communication science as well as practical use for strategic health communication.

[Digital personalized health information services from physicians: survey results of patients' and physicians' acceptance and expectations]

BACKGROUND

The acquisition of health information is fundamental for patient empowerment. In order to support this, new ways of providing information must be found. In this article, the digital personalized provision of health information by physicians as well as the intended use and requirements of patients and physicians are examined.

METHODS

An online survey of a sample of patients stratified for the German population (N = 1,000) and an online survey of physicians (N = 364) on the subject of digital personalized health information services were conducted. The type of information provision in the medical setting, the intention to use it, and the requirements for digital information services were assessed.

RESULTS

Digital personalized information services are still rare. However, patients would support such a service, while physicians are more skeptical. Patients value usability and information quality. With regard to the form of presentation, texts tend to be rated more important than videos. For physicians, on the other hand, it is important that the service comes from a trustworthy provider, complies with guidelines, and is free of charge.

DISCUSSION

The potential of the digital transformation of information provision has so far only been utilized to a limited extent. While the basis for successful implementation seems to be given among patients, physicians still need to overcome their reservations, the benefits of such services need to be communicated, and systemic incentives must be created.

Exploring Functions and Predictors of Digital Health Engagement Among German Internet Users: Survey Study

BACKGROUND

Digital health engagement may serve many support functions, such as providing access to information; checking or evaluating one's state of health; and tracking, monitoring, or sharing health data. Many digital health engagement behaviors are associated with the potential to reduce inequalities in information and communication. However, initial studies suggest that health inequalities may persist in the digital realm.

OBJECTIVE

This study aimed to explore the functions of digital health engagement by describing how frequently respective services are used for a range of purposes and how these purposes can be categorized from the users' perspective. This study also aimed to identify the prerequisites for successfully implementing and using digital health services; therefore, we shed light on the predisposing, enabling, and need factors that may predict digital health engagement for different functions.

METHODS

Data were gathered via computer-assisted telephone interviews during the second wave of the German adaption of the Health Information National Trends Survey in 2020 (N=2602). The weighted data set allowed for nationally representative estimates. Our analysis focused on internet users (n=2001). Engagement with digital health services was measured by their reported use for 19 different purposes. Descriptive statistics showed the frequency with which digital health services were used for these purposes. Using a principal component analysis, we identified the underlying functions of these purposes. Using binary logistic regression models, we analyzed which predisposing factors (age and sex), enabling factors (socioeconomic status, health- and information-related self-efficacy, and perceived target efficacy), and need factors (general health status and chronic health condition) can predict the use of the distinguished functions.

RESULTS

Digital health engagement was most commonly linked to acquiring information and less frequently to more active or interactive purposes such as sharing health information with other patients or health professionals. Across all purposes, the principal component analysis identified 2 functions. Information-related empowerment comprised items on acquiring health information in various forms, critically assessing one's state of health, and preventing health problems. In total, 66.62% (1333/2001) of internet users engaged in this behavior. Health care-related organization and communication included items on patient-provider communication and organizing health care. It was applied by 52.67% (1054/2001) of internet users. Binary logistic regression models showed that the use of both functions was determined by predisposing factors (female and younger age) and certain enabling factors (higher socioeconomic status) and need factors (having a chronic condition).

CONCLUSIONS

Although a large share of German internet users engage with digital health services, predictors show that existing health-related disparities prevail in the digital realm. To make use of the potential of digital health services, fostering digital health literacy at different levels, especially in vulnerable groups, is key.

Communication matters when it comes to adverse events: Associations of adverse events during implant treatment with patients' communication quality and trust assessments

OBJECTIVES

Because patients' trust in their physicians is a critical factor in improving health outcomes and patient response to adverse events, it is important to analyze the determinants of trust. One of these determinants is patient-centered communication. Because the occurrence of adverse events must be communicated to the patient, we asked whether the perceived quality of patient-physician communication acts as an isolating factor between adverse events and patient trust.

METHODS

We proposed and tested a structural equation model linking the occurrence of adverse events to the mediator patient-provider communication quality and to the outcome patient trust. The model was controlled for sociodemographic and health-related factors. We used online survey data from German implant patients (n = 1312), as implant treatment is associated with frequent adverse events such as infections.

RESULTS

Our results show that adverse events during implant treatment are associated with small but significantly lower trust levels. Patient-provider communication quality partially mediates this association.

CONCLUSIONS

Patient trust does not appear to be immune to deterioration from adverse events. Patient-provider communication plays a role in mitigating this association.

PRACTICE IMPLICATIONS

To improve the quality of care, attention should be paid to how adverse events are communicated in a patient-centered manner.

[Sharing information on COVID-19 vaccination: quantitative online survey on actors, content, sources, and motives]

BACKGROUND

A person's opinion about COVID-19 vaccination and their decision for or against the vaccination are determined, among other things, by the information they receive. Therefore, it seems crucial to examine the phenomenon of information sharing in the context of COVID-19 vaccination. The study explores who shares which information about vaccinations with whom, how the sharing of information is related to the seeking of information from various sources, and what the motives are.

METHOD

From 19 June to 13 July 2021, we conducted an online survey with 833 people using the German non-representative Social Sciences' (SoSci) panel. The questionnaire assessed information sharing with strangers and the social environment, the content, and the motives as well as the sources of information. The responses of 828 people were evaluated using descriptive statistics and multiple linear regression analyses.

RESULTS

Older people, women, and unvaccinated individuals were more likely to share information about COVID-19 vaccination. Information was more often shared in the social environment than with strangers. People shared information about benefits and risks of the vaccination as well as their own experiences with vaccinations. People who research websites of health authorities were more likely to share information about the benefits of vaccinations and their own experiences, while people using YouTube or messenger services were more likely to share information about risks. The motives for sharing information are to help others, social exchange, to raise awareness, to gain status, and the fear of being attacked or judged.

CONCLUSION

Information sharing on COVID-19 vaccination is complex in terms of content and motivation. In order to promote vaccination readiness, the range of information offered by public health departments should be expanded and the population's health literacy should be strengthened.

A Comparison of Women's and Men's Online Information Seeking Behaviors about Gender-Related Health Information: A German Stratified Online Survey (Preprint)

BACKGROUND

Gender-sensitive approaches to health communication aim to integrate gender perspectives at all levels of communication, as an individual's biological sex and socially assigned gender identity have an impact on whether and how one acquires what type of health information. Due to the fast and low-cost opportunity to search for a wide range of information, the internet seems to be a particularly suitable place for gender-related health information about diseases of sex-specific organs and diseases where biological differences are associated with different health risks.

OBJECTIVE

This study aims to inform gender-related information provision and acquisition in 2 ways. The first objective was to provide a theory-driven analysis of web-based health information-seeking behavior (HISB) regarding gender-related issues. Therefore, the Planned Risk Information Seeking Model (PRISM), which is one of the most integrative models of HISB, was adapted and applied. Second, we asked for gender-specific motivational determinants of gender-related web-based HISB comparing the predictors in the groups of women and men.

METHODS

Data from a stratified web-based survey of the German population (N=3000) explained gender-related web-based HISB and influencing patterns comparing women and men. The applicability of PRISM to gender-related web-based HISB was tested using structural equation modeling and a multigroup comparison.

RESULTS

The results revealed PRISM as an effective framework for explaining gender-related web-based HISB. The model accounted for 28.8% of the variance in gender-related web-based HISB. Gender-related subjective norms provided the most crucial explanatory power, followed by perceived seeking control. The multigroup comparison revealed differences in the model's explanatory power and the relevance of predictors of gender-related web-based HISB. The share of explained variances of web-based HISB is higher in men than in women. For men, norms were a more relevant promoting factor, whereas web-based HISB of women was more strongly associated with perceived seeking control.

CONCLUSIONS

The results are crucial for gender-sensitive targeting strategies and suggest gender-related health information interventions that address gender-related subjective norms. Furthermore, programs (eg, web-based learning units) should be developed and offered to improve individuals' (perceived) abilities to perform web-based searches for health information, as those with higher control beliefs are more likely to access web-based information.

Expanding the Health Information National Trends Survey Research Program Internationally to Examine Global Health Communication Trends: Comparing Health Information Seeking Behaviors in the U.S. and Germany

The Health Information National Trends Survey (HINTS) is a well-established U.S.-based research program administered by the National Cancer Institute to track the public access to and use of health information. This paper introduces a German research initiative, part of the International Studies to Investigate Global Health Information Trends (INSIGHTS) research consortium. This adaptation of the HINTS is important for initiating analyses of global health communication practices and comparing health information seeking behaviors (HISB) across nations to pinpoint potentials and challenges of health information provision and contribute to a deeper understanding of socio-contextual determinants of HISB. First cross-country comparisons revealed that the share of residents seeking for health information is high in the U.S. (80%) and Germany (74%), but different primary sources are used. Whereas a clear majority of U.S. residents chose the Internet to gather health information (74.9%), Germans most often turn to health professionals (48.0%). Socio-structural and health(care)-related predictors were found to contribute to the explanation of HISB in both countries, whereas information-related predictors were only relevant in Germany. The results indicate the need to engage in patient-provider communication to initiate HISB and to improve the access to information for residents with lower socio-economic backgrounds.

OnkoRiskNET: a multicenter, interdisciplinary, telemedicine-based model to improve care for patients with a genetic tumor risk syndrome

Background

Genetic tumor risk syndromes are responsible for at least five to ten percent of the 4 million cases of cancer diagnosed in Europe every year. Currently, the care of oncological patients suffers from a lack of specialists in medical genetics and also a lack of access to genetic care in rural areas and structured care pathways between oncologists and medical geneticists. As a result, genetic tumor risk syndromes are underdiagnosed with potentially fatal consequences for patients and their families.

Methods

The OnkoRiskNET study is supported by a grant from the Federal Joint Committee of the Federal Republic of Germany. The study will include 2,000 oncological index patients from oncology practices in Lower Saxony and Saxony after the start of the study in July 2021. Randomization is carried out by means of a stepped wedge design at the level of the practices. Patients either go through routine care or the new form of care with structured cooperation between medical geneticists and oncologists, case management and the use of telemedical genetic counseling. Using a mixed-methods approach, the following parameters will be evaluated in the control and intervention group: (1) Conducted genetic counseling sessions by patients with suspected tumor risk syndrome and their first degree relatives; (2) Patient satisfaction and psychological distress after genetic counseling and testing; (3) Factors influencing the acceptance and experience of telemedical genetic counseling; (4) Satisfaction of oncologists and medical genetics with the structured pathway; (5) Cost efficiency of the new form of care.

Discussion

OnkoRiskNET aims to close the gap in care through the formation of a cooperation network between practicing oncologists and specialists in medical genetics and the use of telemedical genetic counseling, thereby, increasing the diagnostic rate in genetic tumor risk syndromes and serving as a model for future genetic care in Germany.

Trial registration

Trial was registered on 01.12.2021 in the German Clinical Trial Register (https://trialsearch.who.int/) with the DRKS-ID: DRKS00026679. Title: Cooperation network for the provision of local care for patients and families with a genetic tumour risk syndrome. Trial acronym: OnkoRiskNET. Protocol version 1.1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08172-2.

Explaining Online Information Seeking Behaviors in People With Different Health Statuses: German Representative Cross-sectional Survey

Background

Worldwide, the internet is an increasingly important channel for health information. Many theories have been applied in research on online health information seeking behaviors (HISBs), with each model integrating a different set of predictors; thus, a common understanding of the predictors of (online) HISB is still missing. Another shortcoming of the theories explaining (online) HISB is that most existing models, so far, focus on very specific health contexts such as cancer. Therefore, the assumptions of the Planned Risk Information Seeking Model (PRISM) as the latest integrative model are applied to study online HISB, because this model identifies the general cognitive and sociopsychological factors that explain health information seeking intention. We shift away from single diseases and explore cross-thematic patterns of online HISB intention and compare predictors concerning different health statuses as it can be assumed that groups of people perceiving themselves as ill or healthy will differ concerning their drivers of online HISB. Considering the specifics of online HISB and variation in individual context factors is key for the development of generalizable theories.

Objective

The objective of our study was to contribute to the development of the concept of online HISB in 2 areas. First, this study aimed to explore individual-level predictors of individuals’ online HISB intention by applying the postulates of PRISM. Second, we compared relevant predictors of online HISB in groups of people with different health statuses to identify cross-thematic central patterns of online HISB.

Methods

Data from a representative sample of German internet users (n=822) served to explain online HISB intentions and influencing patterns in different groups of people. The applicability of the PRISM to online HISB intention was tested by structural equation modeling and multigroup comparison.

Results

Our results revealed PRISM to be an effective framework for explaining online HISB intention. For online HISB, attitudes toward seeking health information online provided the most important explanatory power followed by risk perceptions and affective risk responses. The multigroup comparison revealed differences both regarding the explanatory power of the model and the relevance of predictors of online HISB. The online HISB intention could be better explained for people facing a health threat, suggesting that the predictors adopted from PRISM were more suitable to explain a problem-driven type of information-seeking behavior.

Conclusions

Our findings indicate that attitudes toward seeking health information online and risk perceptions are of central importance for online HISB across different health-conditional contexts. Predictors such as self-efficacy and perceived knowledge insufficiency play a context-dependent role—they are more influential when individuals are facing health threats and the search for health information is of higher personal relevance and urgency. These findings can be understood as the first step to develop a generalized theory of online HISB.

Efficacy Assessments as Predictors of Uncertainty Preferences

Abstract. Background: Health challenges can cause feelings of uncertainty that individuals intend to reduce, increase, or maintain. Those goals are connected to different information seeking and avoidance behaviors, building four uncertainty preferences. Aims: We aim to understand what drives people to seek or avoid information through a more differentiated look at the underlying uncertainty preferences and their determinants. Our starting point to explain different uncertainty preferences are stable, individual traits determining individuals’ efficacy assessments. Method: We conducted a secondary analysis of an online survey among the German public in a sample with stratified demographic characteristics ( N = 3,000). The questionnaire measured different uncertainty preferences as well as coping efficacies and communication efficacy. Regression analyses determined the relevance of these predictors for the four uncertainty preferences. Results: The considered efficacy assessments explained a greater amount of variance in uncertainty preferences applying information seeking than information avoidance, but the influencing patterns are similar. Only health literacy as a communication efficacy was positively associated with both preferences applying information seeking and negatively associated with both preferences applying information avoidance. Limitations: The concept of uncertainty preferences should be critically assessed concerning its completeness. The low explanatory power of efficacy assessments for preferences underlying information avoidance strategies shows that further research is needed to identify relevant predictors. Conclusion: The findings suggest that efficacy assessments provide cognitive resources for goal-oriented uncertainty management, but a deeper understanding of specific underlying mechanisms of the different preferences requires further examination.

Explaining cancer information avoidance comparing people with and without cancer experience in the family

OBJECTIVES

Cancer information avoidance (CIA) serves as a barrier to preventive efforts. To learn how to combat this barrier, we aim to examine predictors of CIA in populations with and without cancer experience in the family, which are addressed differently in cancer prevention, according to specific informational barriers.

METHODS

A subsample of people with and without cancer in the family (n = 2,757) of an online survey with a sample stratified for the German population by age, gender, education, and region was conducted via an online access panel. The survey instrument was adapted from the Health Information National Trends Survey. Separate stepwise regression analyses were conducted.

RESULTS

Only a comparatively small proportion of the variance in CIA was explained by the predictors, ranging from R²  = .148 for people without cancer experience to R²  = .180 for participants with cancer experience in their family. Across the groups, the findings showed that people who were fatalistic about the risk of cancer, less health literate, who perceived less social pressure to be informed, and were less trusting in information sources more often avoided cancer information.

CONCLUSIONS

Our findings identify relevant target groups to be addressed and barriers to be removed for cancer communication efforts. Adequate information provision can be supported by programs for fostering health literacy and social network diffusion strategies.

Correlates of the perceived quality of patient-provider communication among German adults

BACKGROUND

Since a higher perceived quality of patient-provider communication is known to be associated with improved health outcomes, it is essential to analyze determinants influencing patients' perceived quality of patient-provider communication. Due to the limited knowledge about patient-related influencing factors of quality perception available so far, the objective of this study is to explore and assess determinants of the perceived quality of patient-provider communication with regards to sociodemographic, health-related, healthcare-specific and information-related factors.

METHODS

Linear regression of cross-sectional data from the first wave of Health Information National Trends Survey Germany (n = 2902) was conducted. Independent variables were sociodemographic, health-, healthcare- and information-related factors; the dependent variable was the perceived quality of patient-provider communication.

RESULTS

Results show that age, migration background, the perceived quality of healthcare, health-related self-efficacy and trust in health information from health professionals are significantly associated with the perceived quality of patient-provider communication.

CONCLUSIONS

Sociodemographic, healthcare- and health information-related factors influence the perceived quality of patient-provider communication. In particular, patients having a migration background and patients reporting low self-efficacy showed significant lower levels of their perceived patient-provider communication quality. With the aim to improve quality issues, patients of both target groups should be empowered and supported.

Exploratory Research Focusing on Oral Cancer Prevention: Challenges of Dealing With Informational and Cognitive Barriers

Oral cancer is a considerable public health problem, and a low level of awareness and knowledge about this tumor and its risk factors is prevalent. To gain a profound understanding of risks groups and to identify suitable communication strategies for a prevention campaign in Northern Germany, an exploratory research was realized. In semistructured face-to-face interviews, the participants of the study (n = 28) described their individual oral cancer-related perceptions and information-seeking behaviors. A computer-assisted qualitative data analysis showed a vague but also deterring picture of cancer combined with restricted attitudes toward the topic and an inactive or even avoiding information behavior. Four underlying cognitive patterns of self-distancing were identified: (a) optimistic bias, (b) fatalism, (c) hedonism, and (d) pragmatism. The main challenge of oral cancer prevention is to deal with the target groups' informational and cognitive barriers.

Utility of routine oral contrast study for detecting postesophagectomy anastomotic leak - a systematic review and meta-analysis

Oral contrast studies are used to detect anastomotic leak (AL) postesophagectomy. However, recent evidence suggests oral contrast studies have low sensitivity in detecting ALs, and their false positive results can lead to unnecessary prolonged hospital stay. The objective of this study was to determine if oral contrast studies should be used routinely post-esophagectomy for cancer. A systematic literature search was conducted for studies published between January 1990 and June 2018. Data extracted for analyses included type of esophagectomy, operative morbidity (such as AL and pneumonia), mortality rates, timing of contrast study, and type of oral contrast used. The sensitivity, specificity, and positive and negative predictive values of routine oral contrast studies to detect AL were calculated using the aforementioned variables. Two hundred and forty-seven studies were reviewed with 16 studies included in the meta-analysis. Postoperative oral contrast study was performed in 94.0% of cases between day 5 and 7. The rates of early and delayed leaks were 2.4% (1.8%-3.3%) and 2.8% (1.8%-4.4%), respectively. Routine contrast studies have a sensitivity and specificity of 0.44 (0.32-0.57) and 0.98 (0.95-0.99), respectively. Analysis of covariates revealed that sensitivity is reduced in centers with a higher volume of cases (greater than 15 per year: 0.50 [0.34-0.75; p = 0.0008]) and specificity was higher in centers with a lower leak rate. Given its poor sensitivity and inability to detect early/delayed AL, oral contrast study should be used selectively with endoscopy and/or computerized tomography scan to assess surgical anastomoses following esophagectomy.

Allergic manifestation 15 years after early intervention with hydrolyzed formulas--the GINI Study

Background

Data on the long‐term impact of hydrolyzed formulas on allergies are scarce.

Objective

To assess the association between early intervention with hydrolyzed formulas in high‐risk children and allergic outcomes in adolescence.

Methods

GINI trial participants (n = 2252) received one of four formulas in the first four months of life as breastmilk substitute if necessary: partial or extensive whey hydrolyzate (pHF‐W, eHF‐W), extensive casein hydrolyzate (eHF‐C) or standard cow′s milk formula (CMF) as reference. Associations between these formulas and the cumulative incidence and prevalence of parent‐reported physician‐diagnosed asthma, allergic rhinitis (AR) and eczema, as well as spirometric indices and sensitization, were examined using generalized linear models.

Results

Between 11 and 15 years, the prevalence of asthma was reduced in the eHF‐C group compared to CMF (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.26–0.89), which is consistent with the spirometric results. The cumulative incidence of AR was lower in eHF‐C (risk ratio (RR) 0.77, 95% CI 0.59–0.99]) and the AR prevalence in pHF‐W (OR 0.67, 95% CI 0.47–0.95) and eHF‐C (OR 0.59, 95% CI 0.41–0.84). The cumulative incidence of eczema was reduced in pHF‐W (RR 0.75, 95% CI 0.59–0.96) and eHF‐C (RR 0.60, 95% CI 0.46–0.77), as was the eczema prevalence between 11 and 15 years in eHF‐C (OR 0.42, 95% CI 0.23–0.79). No significant effects were found in the eHF‐W group on any manifestation,nor was there an effect on sensitization with any formula.

Conclusion

In high‐risk children, early intervention using different hydrolyzed formulas has variable preventative effects on asthma, allergic rhinitis and eczema up to adolescence.

Opportunities and challenges of entertainment-education: Learning about Parkinson's disease via The Michael J. Fox Show

Health topics are omnipresent in the media. However, although both informational and entertainment formats can increase public understanding of health and illness, media representations of diseases involve challenges as well as opportunities. The entertainment-education (E-E) approach highlights the positive effects of incorporating health messages into entertainment media. The goal of influencing awareness, knowledge and attitudes is reached by transporting the audience into a narrative, which as such enhances persuasive effects and suppresses counterarguing. The NBC sitcom The Michael J. Fox Show (TMJFS) is an E-E format inspired by the actor's own experiences with Parkinson's disease (PD). Using TMJFS as an exemplar, we conducted a multimethodological study to understand both the challenges and the opportunities of E-E comedy formats. A content analysis focusing on the representation of PD in TMJFS showed a focus on motoric symptoms of PD. Subsequent recap analyses and qualitative interviews were conducted to better understand different readings of the show in terms of its informative and entertaining aspects. Additionally, we performed a standardized online survey and an experiment to measure attitudinal effects of TMJFS.

Plerixafor plus pegfilgrastim is a safe, effective mobilization regimen for poor or adequate mobilizers of hematopoietic stem and progenitor cells: a phase I clinical trial

The safety, kinetics and efficacy of plerixafor+pegfilgrastim for hematopoietic stem and progenitor cell (HSPC) mobilization are poorly understood. We treated 12 study patients (SP; lymphoma n=10 or myeloma n=2) with pegfilgrastim (6 mg SC stat D1) and plerixafor (0.24 mg/kg SC nocte from D3). Six SP were 'predicted poor-mobilizers' and six were 'predicted adequate-mobilizers'. Peripheral blood (PB) CD34(+) monitoring commenced on D3. Apheresis commenced on D4. Comparison was with 22 historical controls (HC; lymphoma n=18, myeloma n=4; poor mobilizers n=4), mobilized with pegfilgrastim alone. Eight (67%) SP had PB CD34(+) count ⩽5 × 10(6)/L D3 post pegfilgrastim; all SP surpassed this threshold the morning after plerixafor. In SP, PBCD34(+) counts peaked D4 6/12 (50%), remaining ⩾5 × 10(6)/L for 4 days in 8/12 (67%). All SP successfully yielded target cell numbers (⩾2 × 10(6)/kg) within four aphereses. After maximum four aphereses, median total CD34+ yield was higher in SP than HC; 8.0 (range 2.4-12.9) vs 4.8 (0.4-14.0) × 10(6)/kg (P=0.04). Seven of twelve (58%) SP achieved target yield after one apheresis. Flow cytometry revealed no tumor cells in PB or apheresis product of SP. Plerixafor+pegfilgrastim was well tolerated with bone pain (n=2), diarrhoea (n=2) and facial paraesthesiae (n=3). Plerixafor+pegfilgrastim is a simple, safe and effective HSPC mobilization regimen in myeloma and lymphoma, in both poor and good mobilizers, and is superior to pegfilgrastim alone.

Meta-analysis of mould and dampness exposure on asthma and allergy in eight European birth cohorts: an ENRIECO initiative

BACKGROUND

Several cross-sectional studies during the past 10 years have observed an increased risk of allergic outcomes for children living in damp or mouldy environments.

OBJECTIVE

The objective of this study was to investigate whether reported mould or dampness exposure in early life is associated with the development of allergic disorders in children from eight European birth cohorts.

METHODS

We analysed data from 31 742 children from eight ongoing European birth cohorts. Exposure to mould and allergic health outcomes were assessed by parental questionnaires at different time points. Meta-analyses with fixed- and random-effect models were applied. The number of the studies included in each analysis varied based on the outcome data available for each cohort.

RESULTS

Exposure to visible mould and/or dampness during first 2 years of life was associated with an increased risk of developing asthma: there was a significant association with early asthma symptoms in meta-analyses of four cohorts [0-2 years: adjusted odds ratios (aOR), 1.39 (95% CI, 1.05-1.84)] and with asthma later in childhood in six cohorts [6-8 years: aOR, 1.09 (95% CI, 0.90-1.32) and 3-10 years: aOR, 1.10 (95% CI, 0.90-1.34)]. A statistically significant association was observed in six cohorts with symptoms of allergic rhinitis at school age [6-8 years: aOR, 1.12 (1.02-1.23)] and at any time point between 3 and 10 years [aOR, 1.18 (1.09-1.28)].

CONCLUSION

These findings suggest that a mouldy home environment in early life is associated with an increased risk of asthma particularly in young children and allergic rhinitis symptoms in school-age children.

Metabolic response of rectal cancer assessed by 18-FDG PET following chemoradiotherapy is prognostic for patient outcome

BACKGROUND

Complete pathological response has proven prognostic benefits in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy. Sequential 18-FDG PET may be an early surrogate for pathological response to chemoradiotherapy.

OBJECTIVES

The aim of this study was to identify whether metabolic response measured by FDG PET following chemoradiotherapy is prognostic for tumor recurrence and survival following neoadjuvant therapy and surgical treatment for primary rectal cancer.

METHODS

Patients with primary rectal cancer treated by long-course neoadjuvant chemoradiotherapy followed by surgery had FDG PET performed before and 4 weeks after treatment, before surgical resection was performed. Retrospective chart review was undertaken for patient demographics, tumor staging, recurrence rates, and survival.

RESULTS

: Between 2000 and 2007, 78 patients were identified (53 male, 25 female; median age, 64 y). After chemoradiotherapy, 37 patients (47%) had a complete metabolic response, 26 (33%) had a partial metabolic response, and 14 (18%) had no metabolic response as assessed by FDG PET (1 patient had missing data). However, only 4 patients (5%) had a complete pathological response. The median postoperative follow-up period was 3.1 years during which 14 patients (19%) had a recurrence: 2 local, 9 distant, and 3 with both local and distant. The estimated percentage without recurrence was 77% at 5 years (95% CI 66%-89%). There was an inverse relationship between FDG PET metabolic response and the incidence of recurrence within 3 years (P = .04). Kaplan-Meier analysis of FDG PET metabolic response and overall survival demonstrated a significant difference in survival among patients in the 3 arms: complete, partial, and no metabolic response (P = .04); the patients with complete metabolic response had the best prognosis.

CONCLUSION

Complete or partial metabolic response on PET following neoadjuvant chemoradiotherapy and surgery predicts a lower local recurrence rate and improved survival compared with patients with no metabolic response. Metabolic response may be used to stratify prognosis in patients with rectal cancer.

Association between attendance of day care centres and increased prevalence of eczema in the German birth cohort study LISAplus

BACKGROUND

Day care centre attendance is much more common in East than in West Germany. Although there is evidence that early day care might be protective against atopic diseases, several studies have shown a higher prevalence of childhood eczema in East Germany compared to West Germany.

OBJECTIVES

To compare prevalence and cumulative incidence of eczema in a birth cohort study in East and West Germany and to identify risk factors that are associated with eczema, which might explain regional differences.

METHODS

We used data from the ongoing population-based birth cohort study Influence of Life-style factors on the development of the Immune System and Allergies in East and West Germany Plus the influence of traffic emissions and genetics. In 1997, 3097 children from study areas in East and West Germany were recruited. Cumulative incidence and 1-year prevalences of eczema up to the age of 6 years were determined from yearly questionnaires. Cox regression and generalized estimating equations/logistic regression were used to quantify regional differences and to identify risk factors that might explain them.

RESULTS

Prevalence and incidence of eczema were higher in children living in East Germany than those living in West Germany. We identified 11 risk factors that showed significant regional differences. From these factors, only 'day care attendance during the first 2 years of life' was significantly associated with eczema (odds ratio 1.56, 95% confidence interval CI 1.31-1.86). The regional differences in eczema could be explained by differences in early day care utilization.

CONCLUSION

Day care centre attendance is associated with an increased prevalence and incidence of eczema. Regional differences in eczema prevalence could be explained by regional differences in utilization of early day care.

Screening of multiparous women to avoid transfusion-related acute lung injury: a single centre experience

The aim of this study was to investigate which approach for serological testing of multiparous donors might be feasible and effective to reduce the risk of transfusion-related acute lung injury (TRALI). TRALI is a serious adverse event of blood transfusion. Antibodies to granulocytes and human leucocyte antigens (HLAs) are frequently detected in sera of implicated donors. These donors are often multiparous women. A general deferral of female plasma or screening strategies for leucocyte antibodies has been proposed to increase blood safety. A prospective study was initiated in 2003. Until 2006, serum samples from all female donors reporting three or more pregnancies (n = 229) were screened for the presence of antibodies against granulocytes and HLAs by immunofluorescence and agglutination tests as well as by a commercial HLA enzyme immunoassay. In total, 40% of all multiparous women were reactive in one of the assays. Twenty-nine percent of the reactive sera contained antibodies to granulocytes but not to HLAs. During the observation period, three TRALI reactions occurred in our hospital, two of which would have been prevented if the screening program had been extended to all previously pregnant donors. We conclude from these data that, not unexpectedly, the number of previous pregnancies is not a reliable indicator for the likelihood of inducing TRALI. More importantly, screening strategies for antibodies that might induce TRALI should probably not be reduced to HLA antibody screening. This finding awaits further research.

SLCO1B1 variants and statin-induced myopathy--a genomewide study

BACKGROUND

Lowering low-density lipoprotein cholesterol with statin therapy results in substantial reductions in cardiovascular events, and larger reductions in cholesterol may produce larger benefits. In rare cases, myopathy occurs in association with statin therapy, especially when the statins are administered at higher doses and with certain other medications.

METHODS

We carried out a genomewide association study using approximately 300,000 markers (and additional fine-mapping) in 85 subjects with definite or incipient myopathy and 90 controls, all of whom were taking 80 mg of simvastatin daily as part of a trial involving 12,000 participants. Replication was tested in a trial of 40 mg of simvastatin daily involving 20,000 participants.

RESULTS

The genomewide scan yielded a single strong association of myopathy with the rs4363657 single-nucleotide polymorphism (SNP) located within SLCO1B1 on chromosome 12 (P=4x10(-9)). SLCO1B1 encodes the organic anion-transporting polypeptide OATP1B1, which has been shown to regulate the hepatic uptake of statins. The noncoding rs4363657 SNP was in nearly complete linkage disequilibrium with the nonsynonymous rs4149056 SNP (r(2)=0.97), which has been linked to statin metabolism. The prevalence of the rs4149056 C allele in the population was 15%. The odds ratio for myopathy was 4.5 (95% confidence interval [CI], 2.6 to 7.7) per copy of the C allele, and 16.9 (95% CI, 4.7 to 61.1) in CC as compared with TT homozygotes. More than 60% of these myopathy cases could be attributed to the C variant. The association of rs4149056 with myopathy was replicated in the trial of 40 mg of simvastatin daily, which also showed an association between rs4149056 and the cholesterol-lowering effects of simvastatin. No SNPs in any other region were clearly associated with myopathy.

CONCLUSIONS

We have identified common variants in SLCO1B1 that are strongly associated with an increased risk of statin-induced myopathy. Genotyping these variants may help to achieve the benefits of statin therapy more safely and effectively. (Current Controlled Trials number, ISRCTN74348595.)

Current eczema in children is related to Der f 1 exposure but not to Der p 1 exposure

BACKGROUND

Mite allergen exposure is an important risk factor for specific IgE production and is associated with asthma, hay fever and eczema. Whether these associations are independent of mite species has not been investigated so far.

OBJECTIVES

To investigate the influence of exposure to the major house dust mite (HDM) allergens Der p 1 and Der f 1 on sensitization, respiratory symptoms, and especially on eczema and related skin symptoms in 6-7-year-old children.

METHODS

In a cross-sectional study in Augsburg (Bavaria, Germany) 1669 school beginners (mean age 6.5 years) were investigated in 1996. The concentrations of Der p 1 and Der f 1 were measured in dust samples from mattresses of 1081 children by enzyme-linked immunosorbent assay. The prevalence of atopy-related health outcomes was assessed by questionnaire, dermatological examination, skin prick testing and determination of specific serum IgE concentrations by radioallergosorbent test. Information about covariates was taken from questionnaires and interview data. Logistic regression was used to adjust for confounding.

RESULTS

The mean concentrations of Der p 1 and Der f 1 were 0.68 and 0.79 microg g(-1) dust, respectively. The relationship between the two species-specific allergens in individual homes was poor (Pearson correlation 0.2). Influencing variables were bedroom-sharing (Der p 1) and social status of the parents (Der f 1). Respiratory diseases were positively associated with both allergen concentrations [odds ratio (OR) between 1.1 and 2.6]. These associations were significant for sneezing attacks (Der p 1 and Der f 1). Reported prevalence of current (in the last 12 months) itchy skin rash was significantly associated with exposure to Der f 1 only (OR 2.4, P < 0.003); also a diagnosis of atopic eczema on the day of investigation was positively associated with Der f 1 only (OR 1.8, P = 0.14).

CONCLUSIONS

Studies on the effects of HDM exposure on eczema and allergies should consider specific effects of different mite species. This might have implications on assessment of allergen exposure and consecutive prevention or therapeutic measures.

Glycocalyx-mimetic dextran-modified poly(vinyl amine) surfactant coating reduces platelet adhesion on medical-grade polycarbonate surface

A dextran-modified poly(vinyl amine) comb-like surfactant polymer, poly(N-vinyl dextran aldonamide-co-N-vinyl hexanamide), that can surface-adsorb on hydrophobic polymeric substrates, was designed to improve the interfacial blood-compatibility of polymeric biomaterials. Medical-grade polycarbonate was selected as a model substrate because of its extensive use in blood-contacting biomedical devices like hemodialyzers, blood pumps and oxygenators. The surfactant polymer was physisorbed from aqueous solution onto the polycarbonate substrate. The surfactant coating was stable under dynamic shear conditions in whole blood, as confirmed by fluorescence microscopy and total internal reflection fluorescence (TIRF) experiments with fluorescein-labeled surfactant polymer. The coated disks and uncoated control disks were exposed to platelet-rich plasma (PRP) and whole human blood in a rotating disk system (RDS) to study platelet-adhesion under dynamic shear stress environments. Adhered platelets were stained with fluorescein isothiocyante (FITC)-tagged anti-CD41a monoclonal antibody and imaged by epifluorescence microscopy. Complimentary images were obtained by phase-contrast microscopy. Platelet adhesion on the surfactant-coated disks was reduced by approximately 90%, compared with uncoated disks. The images also showed a concomitant reduction in platelet-derived microparticles on surfactant-coated disks, compared with uncoated disks. The results suggest potential application of carbohydrate-modified surfactant polymers as a glycocalyx-mimetic non-thrombogenic interfacial coating for blood-contacting biomaterials.

The effect of environmental tobacco smoke on eczema and allergic sensitization in children

BACKGROUND

The negative impact of environmental tobacco smoke (ETS) on airway diseases in children is well known. Whether there is an effect on atopic eczema is not clear.

OBJECTIVES

To determine the impact of ETS on atopic eczema, allergic sensitization and allergic airway diseases in 1669 school beginners.

METHODS

The prevalence of atopy-related health outcomes was assessed by questionnaire, dermatological examination, skin prick testing and specific immunoglobulin E measurement. Exposure assessments were based on measurement of cotinine [expressed as cotinine to creatine ratio (CCR)] in spot urine samples (n = 1220) together with questionnaire and interview data on smoking behaviour of the parents.

RESULTS

In the total study group, prevalence of atopic eczema diagnosed on examination was significantly associated with urinary CCR values. The odds ratio (OR) and 95% confidence interval (CI), calculated for an increase of 100 ng mg-1 CCR was 1.97 (95% CI 1.23-3.16). The prevalence of skin manifestations according to questionnaire data as well as a history of asthma, wheezing, and hay fever were positively although not significantly associated with ETS exposure. When genetically predisposed children (defined by the presence of parental atopy) were compared with children whose parents had no atopy, the ORs of allergic outcome variables were generally higher in the first group. In the group of predisposed children, significant associations with urinary CCR were found for allergic sensitization against house dust mites as measured by skin prick test (OR 3.10, 95% CI 1.63-5.90).

CONCLUSIONS

Children are at a higher risk of developing an atopic eczema when exposed to ETS and genetically predisposed children are at higher risk of developing a sensitization against house dust mites.

[Studying school beginners in western and eastern Germany: allergy trends and sensitisations 1991-2000]

AIM

Aim of the study is to examine the hypotheses of a steeper increase in allergies and allergic sensitisations in East than in West German children between 1991 and 2000.

METHOD

Between 1991 and 2000 we yearly repeated cross-sectional studies (SAWO: Study on school beginners) and asked 36,645 parents about diagnoses and symptoms of allergies in their six-year old children (response: 79 %). The study was done in Leipzig, Halle, Merseburg, Magdeburg, small towns in the Altmark region, Duisburg, Essen, Köln and Borken during spring. An allergological investigation was included 1991, 1994, 1997 and 2000. Dermatologists diagnosed a prevalent atopic eczema, administered a skin prick test (n = 7,229) and blood was taken for the determination of specific IgE antibodies against common allergens (n = 7,714, RAST). Odds Ratios (OR) for trend were calculated separately for the data from East and West Germany and are given along with their 95% confidence intervals.

RESULTS

Allergies and their symptoms (exception: atopic eczema) were less prevalent in East German children born before the reunification than in West German ones. In East as well as in West Germany bronchial asthma was diagnosed more often in 2000 than in 1991 (OR East: 2.42 [1.78-3.28] West: 2.07 [1.43-3.00]). In contrast the prevalence of atopic eczemas was more than halved between 1991 and 2000. Of all symptoms and diagnoses of allergies only hay fever and its symptoms showed an upward trend in East Germany which was steeper than the trend in West Germany (OR East: 4.41 [3.17-6.13] West: 1.74 [1.19-2.57]). This can partly be explained by a parallel trend in sensitisation against grass pollen.

CONCLUSION

The spatial and temporal pattern of the allergic diseases bronchial asthma, hay fever and atopic eczema in six-year old children from Germany is different. The expected steeper increase of allergies in East than in West Germany could only be shown for hay fever.

Distribution of synaptic vesicle proteins in the mammalian retina identifies obligatory and facultative components of ribbon synapses

The mammalian retina contains two synaptic layers. The outer plexiform layer (OPL) is primarily composed of ribbon synapses while the inner plexiform layer (IPL) comprises largely conventional synapses. In presynaptic terminals of ribbon synapses, electron-dense projections called ribbons are present at the synaptic plasma membranes. Ribbons bind synaptic vesicles and guide them to the synaptic membrane for fusion. In this manner, ribbons are thought to accelerate the delivery of vesicles for continuous exocytosis. In recent years, a large number of synaptic proteins has been described but it is not known if these protein colocalize in the same types of synapses. In previous studies, several proteins essential for synaptic function were not detected in ribbon synapses, suggesting that the mechanism of synaptic vesicle exocytosis may be very different in ribbon and conventional synapses. Using confocal laser scanning microscopy, we have now systematically investigated the protein composition of ribbon synapses. Our results show that, of the 19 synaptic proteins investigated, all except synapsin and rabphilin are obligatorily present in ribbon synapses. For example, rab3 which was reported to be absent from ribbon synapses, was found in bovine, rat and mouse ribbon synapses using multiple independent antibodies. In addition, we found staining in these synapses for PSD-95 and NMDA receptors, which suggested a similar design for the postsynaptic component in ribbon and conventional synapses. Our data show that ribbon synapses are more conventional in composition than reported, that most synaptic proteins are colocalized to the same type of synapse, and that synapsin and rabphilin are likely to be dispensible for basic synaptic functions.

De novo acquisition of neuronal polarity in retinoic acid-induced embryonal carcinoma cells

The mouse embryonal carcinoma cell line PCC7-Mz1 represents an advantageous model to study acquisition of polarity by neurons. During the first two days after differentiation is induced by the addition of retinoic acid, the neuronal derivatives develop extensions which for at least four more days do not differ from each other in growth characteristics, morphology, and marker expression. Beginning around differentiation day 6 and following the relocation of the nucleus from a central to a polar position in the cell soma, the morphology and marker expression changes dramatically: expression of MAP2 diminishes and eventually disappears in the thinner neurite (future axon), which originates at the nucleated pole, but remains strong in the branched, broad based neurite(s). The opposite changes in expression are observed for synaptophysin, together with a clustering of the vesicle protein in varicosity-like areas. Complete segregation of expression of the two markers is achieved around day 12, shortly followed by dendrite-specific location of MAP2 mRNA and the ability to generate and conduct action potentials. Our studies add several aspects to the process of neuronal polarity acquisition, as it was previously studied in primary cultures of embryonic neurons: (i) we monitored neuronal differentiation from the birth of neurons, rather than from later and less defined maturation stages, (ii) cell nucleus relocation may be associated with the induction of neuronal polarity, and (iii) functional competence of neurons is closely associated with previous acquisition of polarity. Acquisition of polarity by PCC7-Mz1 neuronal derivatives probably refers to de novo acquisition rather than to reestablishment of polarity.

Cleavage of members of the synaptobrevin/VAMP family by types D and F botulinal neurotoxins and tetanus toxin

Tetanus toxin (TeTx) and the various forms of botulinal neurotoxins (BoNT/A to BoNT/G) potently inhibit neurotransmission by means of their L chains which selectively proteolyze synaptic proteins such as synaptobrevin (TeTx, BoNT/B, BoNT/F), SNAP-25 (BoNT/A), and syntaxin (BoNT/C1). Here we show that BoNT/D cleaves rat synaptobrevin 1 and 2 in toxified synaptosomes and in isolated vesicles. In contrast, synaptobrevin 1, as generated by in vitro translation, is only a poor substrate for BoNT/D, whereas this species is cleaved by BoNT/F with similar potency. Cleavage by BoNT/D occurs at the peptide bond Lys59-Leu60 which is adjacent to the BoNT/F cleavage site (Gln58-Lys59) and again differs from the site hydrolyzed by TeTx and BoNT/B (Gln76-Phe77). Cellubrevin, a recently discovered isoform expressed outside the nervous system, is efficiently cleaved by all three toxins examined. For further characterization of the substrate requirements of BoNT/D, we tested amino- and carboxyl-terminal deletion mutants of synaptobrevin 2 as well as synthetic peptides. Shorter peptides containing up to 15 amino acids on either side of the cleavage site were not cleaved, and a peptide extending from Arg47 to Thr116 was a poor substrate for all three toxins tested. However, cleavability was restored when the peptide is further extended at the NH2 terminus (Thr27-Thr116) demonstrating that NH2 terminally located sequences of synaptobrevin which are distal from the respective cleavage sites are required for proteolysis. To further examine the isoform specificity, several mutants of rat synaptobrevin 2 were generated in which individual amino acids were replaced with those found in rat synaptobrevin 1. We show that a Met46 to Ile46 substitution drastically diminishes cleavability by BoNT/D and that the presence of Val76 instead of Gln76 dictates the reduced cleavability of synaptobrevin isoforms by TeTx.