Virtual reality roleplays for patients with depression: A user experience evaluation

Background

Virtual reality (VR) has been used successfully and effectively in psychotherapy for a variety of disorders. In the field of depression, there are only a few VR interventions and approaches. Although simple social interactions have been successfully modeled in VR for several mental disorders, there has been no transfer to the field of depression therapy. VR may be employed for psychodynamic psychotherapy to work on interpersonal conflict patterns. In this study, we developed and evaluated a VR intervention for the simulation of roleplay situations in the context of supportive-expressive therapy.

Methods

We conducted a clinical user experience (UX) study at a psychotherapeutic clinic in Düsseldorf, Germany. Eight inpatients with depression and four therapists were included. Semi-structured interviews and qualitative content analysis were used to identify UX issues of the developed VR intervention. Usability questionnaires and technical usage data were also considered. The VR intervention consisted of two therapist-controlled roleplay scenarios designed to support work on the core conflictual relationship theme by allowing patients to interact in typical problematic social situations. Recorded VR roleplays allow for therapeutic debriefing with a change of perspective. Therapists were given the option of using the roleplay in multiple sessions.

Results

All therapists conducted one session per patient with the VR intervention. From the patient interviews, 26 UX issues were extracted, of which one technical malfunction and two unclarities in the interaction with the VR agent were rated as major problems. From the therapist interviews, 14 UX issues were extracted, of which five were rated as major problems related to the interface in the dialog control or the complex system setup.

Conclusion

The main problem was designing a dialog structure that allows both complex conversational flows and a clear control interface. In principle, VR roleplays could be integrated well and safely into therapy. The VR intervention shows promise for providing an emotional experience of interpersonal conflict patterns in the context of psychotherapy. Additionally, other roleplay situations involving various social problem areas must be created and evaluated in terms of the fit to the patients' core conflictual relationship themes.

Family resilience of families with parental cancer and minor children: a qualitative analysis

Introduction

Estimated 50,000 minor children in Germany experience a newly diagnosed cancer in one of their parents every year. Family resilience has proven to be an important concept against life crises. However, little research exists regarding family resilience in the context of parental cancer with minor children. Based on the "Family Resilience Framework," the aim of the study is to investigate the processes of family resilience of affected families. In addition, we explore which combinations of promoting family resilience processes can be characterized.

Methods

As part of the mixed-method quasi-experimental interventional study "F-SCOUT," a qualitative content analysis was used to analyze the documentation of the "Family-Scouts" (a fixed contact person who advises, accompanies, and supports the families). Documentation was performed by families' study inclusion (T0), after 3 months (T1) and 9 months (T2) concerning current family situation, organization of everyday life, emotional coping, open communication within the family, and planned tasks.

Results

The N = 73 families had between one and six children. In 58 (79%) families, the mother had cancer. In the course of the analysis, a category system with 10 main categories and 36 subcategories emerged. Family resilience processes were described to different extents. Combinations of categories promoting family resilience were characterized by the use of social resources, flexibility, economic resources, and open communication.

Discussion

The findings are consistent with existing assumptions about family resilience in terms of the importance of social resources, family cohesion, mutual support, flexibility, open communication, and psychological well-being. In contrast to the findings of previous research, spirituality, and collaborative problem-solving indicate less centrality here. In turn, the findings on economic resources and information-seeking provide a valuable addition to the family resilience literature in the context of parental cancer with minor children.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04186923.

Caring for dependent children impacts practical and emotional problems and need for support, but not perceived distress among cancer patients

OBJECTIVE

More than one in 10 cancer patients care for dependent children. It is unclear whether this status makes a difference in terms of the distress and associated problems they experience, or whether it is linked to differences in the need for or utilization of psychosocial support.

METHODS

Secondary analysis of a cross-sectional German study in National Comprehensive Cancer Centers using self-report standardized questionnaires administered to inpatients. Patients living with dependent children (n = 161) were matched by age and sex with a subsample of 161 cancer patients not living with dependent children. The resulting sample was tested for between-group differences in Distress Thermometer (DT) scores and the corresponding DT Problem List. Additionally, between-group differences in measures of the need for and utilization of psychosocial support were examined.

RESULTS

More than 50% of all patients suffered from clinically relevant distress. Patients living with dependent children reported significantly more practical (p < 0.001, η2 p = 0.04), family (p < 0.001, η2 p = 0.03), and emotional problems (p < 0.001, η2 p = 0.01). Although reporting a greater need for psychological support, parents with cancer were not found to more frequently utilize any type of psychosocial support.

CONCLUSIONS

The specific problems and needs of parents with cancer who care for dependent children are currently not sufficiently addressed in the clinical care pathways. All families should be helped to establish open and honest communication as well as understand the available support systems and what they can provide. Tailored interventions should be implemented for highly distressed families.

The influence of patient-centered teaching on medical students' stigmatization of the mentally ill

Aim

Stigmatization by healthcare workers poses a challenge to providing care to the mentally ill. Bedside teaching during undergraduate medical education offers students an opportunity to directly interact with patients with a range of psychiatric disorders and thereby gather reflective experience. The present study investigates if this supervised contact with mentally ill patients during a one-week clinical course on psychosomatic medicine leads to stigma reduction in medical students. The factors influencing stigmatization were also investigated.

Method

This was a prospective, non-randomized, controlled interventional study done in the 2019/20 winter semester involving fourth-year medical students who attended a week-long practical block on psychosomatic medicine (intervention group). This group was compared to students who had attended a week-long practical block with a somatic focus during the same time period (control group). Stigmatization was measured before and immediately upon completion of the week using the MICA-4 scale. Data on age, sex, experience with the mentally ill, interest in psychiatry/psychosomatics, and sense of self-worth were also gathered prior to starting the practical block. Analysis of the sample of 143 students with a complete basic data set was carried out using mixed ANOVA, multiple linear regression and moderator analysis.

Results

In the context of clinical teaching with psychiatric patients, the stigmatization of the mentally ill among medical students decreased significantly more in the intervention group compared to the students in the control group who received instruction on somatic topics (p=.019, η2p=.04). In addition, being female, having previous experience with the mentally ill and general interest in the subjects of psychiatry or psychosomatics at T0 associated with lower stigma. In contrast, stigmatization was increased at the beginning of the study in males and those with low self-esteem. A moderating effect of the factors on stigma reduction was not seen.

Conclusion

Undergraduate clinical instruction that enables direct contact and reflective experiences with the mentally ill leads to a reduction in the stigmatizing attitudes held by medical students toward the mentally ill. This underscores the need to have practical clinical instruction using patients.

Mindfulness and compassion training on daily work with patients and within the multiprofessional palliative care team: a retrospective self-assessment study

BACKGROUND

Palliative care teams work under challenging conditions in a sensitive setting with difficult tasks. The multi-professional team can play an important role. Mindfulness and compassion-based practices are used to build resilience. Our aim was to examine (1) feasibility and acceptability, (2) satisfaction and impact, and (3) opportunities and limitations of a mindfulness course.

METHODS

An eight-week mindfulness and compassion course was delivered in a university-based specialized palliative care unit. A meditation teacher provided preparatory evening sessions and meditation exercises that could be integrated into daily activities. The scientific analysis of the course was based on a questionnaire developed for quality assessmentThe first two parts consisted of demographic, Likert-type, and free-text items. Part 3 consisted of learning objectives that were self-assessed after finishing the course (post-then). In the analysis, we used descriptive statistics, qualitative content analysis, and comparative self-assessment.

RESULTS

Twenty four employees participated. 58% of participants attended 4 or more of the 7 voluntary mindfulness days. 91% expressed moderate to high satisfaction and would recommend the palliative care program to others. Three main categories emerged in the qualitative content analysis: providing feedback on the course, personal impact, and impact on professional life. The opportunity for self-care in a professional context was highlighted. Learning gains (CSA Gain) were high (38.5-49.4%) in terms of knowledge and techniques, moderate (26.2-34.5%) in terms of implementation of learned skills, and rather low (12.7-24.6%) in terms of changes to attitude.

CONCLUSION

Our evaluation shows that the participants of a mindfulness and compassion course considered it as a feasible and welcome tool to familiarize a multi-professional palliative care team with self-care techniques.

TRIAL REGISTRATION

Internal Clinical Trial Register of the Medical Faculty, Heinrich Heine University Düsseldorf, No. 2018074763 (registered retrospectively on 30^th July 2018).

Palliative Care e-Learning for Physicians Caring for Critically Ill and Dying Patients during the COVID-19 Pandemic: An Outcome Evaluation with Self-Assessed Knowledge and Attitude

During the COVID-19 pandemic, the care of critically ill and dying patients in isolation wards, intensive care units (ICUs), and regular wards was severely impaired. In order to support physicians in communicative and palliative care skills, an e-learning tool was developed as part of the joint project "Palliative Care in Pandemic Times" (PallPan). This study investigates the feasibility of this e-learning tool. Secondly, we aim to analyze changes in knowledge and attitude upon completion of the e-learning tool. A 38-item questionnaire-based evaluation study with assessment of global and specific outcomes including ICU and non-ICU physicians was performed. In total, 24 questionnaires were included in the anonymous analysis. Feasibility was confirmed by a very high rate of overall satisfaction (94% approval), with relevance reaching 99% approval. Overall, we detected high gains in knowledge and noticeably lower gains on the attitude plane, with the highest gain in naming reasons for incorporating palliative care. The lowest learning gain on the attitude plane was observed when the participants were confronted with their own mortality. This study shows that e-learning is a feasible tool for gaining knowledge and even changing the attitudes of physicians caring for critically ill and dying patients in a self-assessment evaluation.

Patient participation in multidisciplinary tumor conferences in breast and gynecological cancer care: How patient-centered is the communication?

OBJECTIVE

Patients' participation is part of patient-centeredness, but it is so far unclear whether providers in multidisciplinary tumor conferences (MTCs) with patient participation communicate in a patient-centered way. Our aim is to explore (a) to what extent providers ask questions to breast and gynecological cancer patients during case discussion in MTCs, (b) how providers respond to patients' expressions of emotions during case discussions, and (c) which patient- and context-related characteristics and responses are associated with patients' trust in the treatment team after the case discussion.

METHODS

This observational study included survey data and audio recordings of MTCs with patient participation at three breast and gynecological cancer centers. Providers' questions to patients and responses to patients' emotional expressions were coded using the Verona Coding Definitions of Emotional Sequences. The response can be explicitly or non-explicitly related to the emotion and space-reducing or space-providing. Multiple linear regression analysis was used to determine associations between providers' responses, patient- and context-related characteristics, and patients' trust in the treatment team after the case discussion.

RESULTS

We analyzed 82 case discussions (77 breast, 5 breast and gynecological cancer patients). Providers asked a total of 646 questions, of which 86% were polar (yes/no). Providers gave 303 responses to a total of 230 emotional expressions by patients. Non-explicit responses were associated with more trust when they were space-providing, but with less trust when space-reducing.

CONCLUSIONS

The frequency of providers' closed questions and space-reducing responses to emotions shows that patient-centered communication rarely takes place in MTCs with patient participation.

A Systematic Review: The Effect of Cancer on the Divorce Rate

Introduction

Research on the impact of cancer on close relationships brings up conflicting results. This systematic review collects empirical evidence on the research questions whether a cancer diagnosis in general or the type of cancer affects the divorce rate.

Materials and Methods

This systematic review was conducted according to the guidelines of the Cochrane Collaboration and the PRISMA statement. The following electronic databases were searched: Web of Science, Ovid SP MEDLINE, PsycINFO, PsyINDEX, CINAHL, ERIC. Risk of bias assessment was performed with the preliminary risk of bias for exposures tool template (ROBINS-E tool). The grading of methodological quality was assessed with the Newcastle-Ottawa Scale.

Results

Of 13,929 identified records, 15 were included in the qualitative synthesis. In 263,616 cancer patients and 3.4 million healthy individuals, we found that cancer is associated with a slightly decreased divorce rate, except for cervical cancer, which seems to be associated with an increased divorce rate.

Discussion

According to this systematic review, cancer is associated with a tendency to a slightly decreased divorce rate. However, most of the included studies have methodologic weaknesses and an increased risk of bias. Further studies are needed.

Participative development and evaluation of a communication skills-training program for oncologists-patient perspectives on training content and teaching methods

Background

Using the 6-step approach to curriculum development for medical education, we developed a communication skills training (CST) curriculum for oncology and evaluated this curriculum from the perspective of cancer patients.

Methods

We conducted a qualitative interview study with cancer patients, collecting data using semi-structured face-to-face or telephone interviews with a short standardized survey. We fully transcribed the audiotaped interviews and conducted the content analysis using MAXQDA 2020. We analyzed the quantitative sociodemographic data descriptively.

Results

A total of 22 cancer patients participated, having a mean age of 60.6 (SD, 13.2) years and being predominantly female (55%). The patients believed that the CST curriculum addressed important aspects of patient-centered communication in cancer care. They emphasized the importance of physicians acquiring communication skills to establish a trusting relationship between doctor and patient, show empathy, inform patients, and involve them in treatment decisions. The patients had some doubts concerning the usefulness of strict protocols or checklists (e.g., they feared that protocol adherence might disturb the conversation flow).

Discussion

Although it was a challenge for some participants to take the perspective of a trainer and comment on the CST content and teaching methods, the patients provided a valuable perspective that can help overcome blind spots in CST concepts.

Psychooncological care for patients with cancer during 12 months of the Covid-19 pandemic: Views and experiences of senior psychooncologists at German Comprehensive Cancer Centers

A monthly videoconference was maintained over 1 year, allowing senior psychooncologists from German Comprehensive Cancer Centers to discuss the implications of the Covid‐19 pandemic for psychooncological care.

In the early phase of the pandemic, a widespread disruption of psychooncological services was noted.

Rapidly developed adaptations of regular services worked well and sometimes brought about unexpected, creative solutions.

In March 2021, the high numbers of infections, the occurrence of new variants of the coronavirus, and the slow progress in vaccination raise fears about new disruptions and restrictions in service provision.

In coping with the pandemic, many therapists have felt like many cancer patients do feel in the process of coping with cancer, and this might help to better understand our patients.

Cancer and Relationship Dissolution: Perspective of Partners of Cancer Patients

Purpose

Cancer can be a burden on the relationship and even lead to relationship dissolution. Previous studies about the impact of cancer on close relationships almost exclusively involve cancer patients. So far, little is known about the views of spouses. Therefore, this study focuses on partners or ex-partners of cancer patients.

Methods

In this cross-sectional study, N = 265 partners or ex-partners of cancer patients are examined regarding a possible separation, the reasons for separation and the influence of the cancer on the relationship. In addition, predictors of separation and the positive or negative perception of the impact of cancer on the relationship were investigated.

Results

The separation rate (23.4%) was marginally lower than in the general population in Germany (35.79%). The most frequent reason for separation was the death of the cancer patient (59.6%), followed by relationship problems (26.9%), and the cancer disease itself (9.6%). Among those who were separated, 57.4% reported that cancer contributed to the separation. On average, the influence of cancer on relationship dissolution is indicated with 82.9%. Also, for those who stayed together, 83.7% reported an impact of the cancer on the relationship, of which 55.9% reported a negative impact. Logistic regressions indicated that higher levels of depression were associated with greater odds of a more negative perception of the influence of cancer on the relationship, whereas a more satisfied relationship tended to be associated with a more positive perception. Those who had no psychological treatment in the past, lower anxiety levels and lower relationship satisfaction had an increased risk of separation. Overall, relationship satisfaction was significantly lower than in the general population in Germany.

Conclusion

In particular, psychological factors such as depression and anxiety as well as relationship satisfaction appear to be factors influencing separation and the perception of the influence of cancer on the relationship as positive or negative. Therefore, it seems to be reasonable to consider these aspects in the psychosocial support and also to include the partners in order to achieve a stable and satisfied relationship which has a positive effect on health and psychological well-being.

Molecular discrimination of Hyalomma tick species serving as reservoirs and vectors for Crimean-Congo hemorrhagic fever virus in sub-Saharan Africa

The species identification of tick vectors of Crimean-Congo hemorrhagic fever virus (CCHFV), especially Hyalomma (H.) species, is a prerequisite to understand the eco-epidemiology of this disease and to reveal vector and virus reservoir species. However, the morphologic species discrimination can be difficult for damaged or blood-fed ticks and in case of species intercrosses. Therefore, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and restriction fragment length polymorphism (RFLP) analysis to distinguish the most common Hyalomma species from sub-Saharan Africa (H. truncatum, H. rufipes and H. dromedarii). Within the last years, MALDI-TOF MS analysis based on tick leg proteins has been shown to be a reliable method to distinguish several tick species. For this purpose, a reference spectral library of several European, American and African tick species was established. In this study, six different Hyalomma species were tested, all of which were all clearly distinguishable by mass spectrometric analyses. Moreover, MALDI TOF- MS was able to confirm morphologic findings where sequencing provided ambiguous results. In addition, a polymerase chain reaction (PCR) based on the CO1 gene amplification of ticks has been developed for the unequivocal species identification by amplicon sequencing and specific restriction endonuclease cleavage pattern analysis. RFLP proved to be a feasible auxiliary discrimination tool for selected Hyalomma species when access to sequencing methods is not available, as for instance during field studies.

Prostate-specific health-related quality of life and patient-physician communication - A 3.5-year follow-up

OBJECTIVE

The aim of this study is to examine associations between prostate-specific health-related quality of life (HRQOL) and aspects of patient-physician communication in localized prostate cancer treatment.

METHODS

Data of patients with localized prostate cancer were collected at 6-month intervals over a 3.5-year period within a prospective, observational study (HAROW). Data collection comprised D'Amico risk categories, the Charlson Comorbidity Index, patient-physician communication (information, shared decision making, support, devotion), and prostate-specific HRQOL (incontinence aid, urinary symptoms, bowel symptoms, hormonal treatment-related symptoms, sexual functioning, sexual activity). Data of N = 1722 patients undergoing radical prostatectomy were analyzed by longitudinal multilevel analysis.

RESULTS

The mean patient age was 65 years; 31% had a low risk and 38% an intermediate risk of cancer growth and spread; 73% had a Charlson Comorbidity Index of 0. Significant associations were found between prostate-specific HRQOL and shared decision making, support and devotion. Patient information was not significantly associated with aspects of prostate-specific HRQOL.

CONCLUSION

Patient reported long term outcomes are associated with aspects of patient-physician communication in prostate cancer patients. Patients feeling involved by their urologists experience less side effects of (surgical) treatment.

PRACTICE IMPLICATIONS

Special communication training programmes should be developed and implemented for urologists.

Imaging Mass Spectrometry and Proteome Analysis of Marek's Disease Virus-Induced Tumors

The highly oncogenic alphaherpesvirus Marek's disease virus (MDV) causes immense economic losses in the poultry industry. MDV induces a variety of symptoms in infected chickens, including neurological disorders and immunosuppression. Most notably, MDV induces transformation of lymphocytes, leading to T cell lymphomas in visceral organs with a mortality of up to 100%. While several factors involved in MDV tumorigenesis have been identified, the transformation process and tumor composition remain poorly understood. Here we developed an imaging mass spectrometry (IMS) approach that allows sensitive visualization of MDV-induced lymphoma with a specific mass profile and precise differentiation from the surrounding tissue. To identify potential tumor markers in tumors derived from a very virulent wild-type virus and a telomerase RNA-deficient mutant, we performed laser capture microdissection (LCM) and thereby obtained tumor samples with no or minimal contamination from surrounding nontumor tissue. The proteomes of the LCM samples were subsequently analyzed by quantitative mass spectrometry based on stable isotope labeling. Several proteins, like interferon gamma-inducible protein 30 and a 70-kDa heat shock protein, were identified that are differentially expressed in tumor tissue compared to surrounding tissue and naive T cells. Taken together, our results demonstrate for the first time that MDV-induced tumors can be visualized using IMS, and we identified potential MDV tumor markers by analyzing the proteomes of virus-induced tumors.IMPORTANCE Marek's disease virus (MDV) is an oncogenic alphaherpesvirus that infects chickens and causes the most frequent clinically diagnosed cancer in the animal kingdom. Not only is MDV an important pathogen that threatens the poultry industry but it is also used as a natural virus-host model for herpesvirus-induced tumor formation. In order to visualize MDV-induced lymphoma and to identify potential biomarkers in an unbiased approach, we performed imaging mass spectrometry (IMS) and noncontact laser capture microdissection. This study provides a first description of the visualization of MDV-induced tumors by IMS that could be applied also for diagnostic purposes. In addition, we identified and validated potential biomarkers for MDV-induced tumors that could provide the basis for future research on pathogenesis and tumorigenesis of this malignancy.

Examiner characteristics and interrater reliability in a communication OSCE

OBJECTIVE

To identify inter-individual examiner factors associated with interrater reliability in a summative communication OSCE in the 4th study year.

METHODS

The OSCE consists of 4 stations assessed with a 4-item 5-point global rating instrument. A bivariate secondary analysis of interrater reliability in relation to 4 examiner factors (gender, profession, OSCE experience, examiner training) was conducted. Intraclass correlation coefficients (ICC) were calculated and compared between examiner dyads of different similarity.

RESULTS

169 pairwise ratings from 19 different examiners in 16 dyads were analysed. Interrater reliability is significantly higher in examiner dyads of same vs. different gender (ICC=0.76 (95%CI=0.65-0.83) vs. ICC=0.41 (95%CI=0.21-0.57)), in dyads of two clinicians vs. non-clinical/mixed professions (ICC=0.72 (95%CI=0.56-0.83) vs. ICC=0.57 (95%CI=0.41-0.69)), and in dyads with high vs. low/mixed OSCE experience (ICC=0.73 (95%CI 0.50-0.87) vs. ICC=0.56 (95%CI=0.41-0.69)). Participation in recent examiner training had no influence on ICCs.

CONCLUSION

Better concordance of ratings between clinically active examiners might be a hint for context specificity of good communication. Higher interrater reliability between examiners with same gender may indicate gender-specific communication concepts.

PRACTICE IMPLICATIONS

Medical faculties introducing summative assessment of communication competence should focus the influence of examiner characteristics on interrater reliability.

[12-Month Prevalence and Consequences of Current Experiences of Physical and Psychological Violence in a Sample of Patients who Entered First Time a Psychotherapeutic Outpatient Clinic]

Objective To examine current experiences of violence and its relationship with psychological burden in a psychotherapeutic outpatient sample. Methods 1074 patients of a psychotherapeutic outpatient-clinic of a university hospital completed a written violence screening questionnaire. Results Current experienced physical and psychological violence was two times higher compared to general population. Patients who experienced current violence reported significantly more psychological burden. Conclusion Use of violence screening in daily routine of a psychotherapeutic outpatient-clinic seems to be a promising approach to detect violence experiences.

Workplace-based assessment of communication skills: A pilot project addressing feasibility, acceptance and reliability

Background: Imparting communication skills has been given great importance in medical curricula. In addition to standardized assessments, students should communicate with real patients in actual clinical situations during workplace-based assessments and receive structured feedback on their performance. The aim of this project was to pilot a formative testing method for workplace-based assessment. Our investigation centered in particular on whether or not physicians view the method as feasible and how high acceptance is among students. In addition, we assessed the reliability of the method. Method: As part of the project, 16 students held two consultations each with chronically ill patients at the medical practice where they were completing GP training. These consultations were video-recorded. The trained mentoring physician rated the student's performance and provided feedback immediately following the consultations using the Berlin Global Rating scale (BGR). Two impartial, trained raters also evaluated the videos using BGR. For qualitative and quantitative analysis, information on how physicians and students viewed feasibility and their levels of acceptance was collected in written form in a partially standardized manner. To test for reliability, the test-retest reliability was calculated for both of the overall evaluations given by each rater. The inter-rater reliability was determined for the three evaluations of each individual consultation. Results: The formative assessment method was rated positively by both physicians and students. It is relatively easy to integrate into daily routines. Its significant value lies in the personal, structured and recurring feedback. The two overall scores for each patient consultation given by the two impartial raters correlate moderately. The degree of uniformity among the three raters in respect to the individual consultations is low. Discussion: Within the scope of this pilot project, only a small sample of physicians and students could be surveyed to a limited extent. There are indications that the assessment can be improved by integrating more information on medical context and student self-assessments. Despite the current limitations regarding test criteria, it is clear that workplace-based assessment of communication skills in the clinical setting is a valuable addition to the communication curricula of medical schools.

Implementation of palliative care as a mandatory cross-disciplinary subject (QB13) at the Medical Faculty of the Heinrich-Heine-University Düsseldorf, Germany

Background: By means of the revision of the Medical Licensure Act for Physicians (ÄAppO) in 2009, undergraduate palliative care education (UPCE) was incorporated as a mandatory cross sectional examination subject (QB13) in medical education in Germany. Its implementation still constitutes a major challenge for German medical faculties. There is a discrepancy between limited university resources and limited patient availabilities and high numbers of medical students. Apart from teaching theoretical knowledge and skills, palliative care education is faced with the particular challenge of imparting a professional and adequate attitude towards incurably ill and dying patients and their relatives.

Project description: Against this background, an evidence-based longitudinal UPCE curriculum was systematically developed following Kern’s Cycle [1] and partly implemented and evaluated by the students participating in the pilot project. Innovative teaching methods (virtual standardised/simulated patient contacts, e-learning courses, interdisciplinary and interprofessional collaborative teaching, and group sessions for reflective self-development) aim at teaching palliative care-related core competencies within the clinical context and on an interdisciplinary and interprofessional basis.

Results: After almost five years of development and evaluation, the UPCE curriculum comprises 60 teaching units and is being fully implemented and taught for the first time in the winter semester 2014/15. The previous pilot phases were successfully concluded. To date, the pilot phases (n=26), the subproject “E-learning in palliative care” (n=518) and the blended-learning elective course “Communication with dying patients” (n=12) have been successfully evaluated.

Conclusion: All conducted development steps and all developed programmes are available for other palliative care educators (Open Access). The integrated teaching formats and methods (video, e-learning module, interprofessional education, group sessions for reflexive self-development) and their evaluations are intended to make a contribution to an evidence-based development of palliative care curricula in Germany.

Summative assessment of undergraduates' communication competence in challenging doctor-patient encounters. Evaluation of the Düsseldorf CoMeD-OSCE

OBJECTIVE

To evaluate the summative assessment (OSCE) of a communication training programme for dealing with challenging doctor-patient encounters in the 4th study year.

METHODS

Our OSCE consists of 4 stations (breaking bad news, guilt and shame, aggressive patients, shared decision making), using a 4-item global rating (GR) instrument. We calculated reliability coefficients for different levels, discriminability of single items and interrater reliability. Validity was estimated by gender differences and accordance between GR and a checklist.

RESULTS

In a pooled sample of 456 students in 3 OSCEs over 3 terms, total reliability was α=0.64, reliability coefficients for single stations were >0.80, and discriminability in 3 of 4 stations was within the range of 0.4-0.7. Except for one station, interrater reliability was moderate to strong. Reliability on item level was poor and pointed to some problems with the use of the GR.

CONCLUSION

The application of the GR on regular undergraduate medical education shows moderate reliability in need of improvement and some traits of validity. Ongoing development and evaluation is needed with particular regard to the training of the examiners.

PRACTICE IMPLICATIONS

Our CoMeD-OSCE proved suitable for the summative assessment of communication skills in challenging doctor-patient encounters.

Implementation of the interdisciplinary curriculum Teaching and Assessing Communicative Competence in the fourth academic year of medical studies (CoMeD)

INTRODUCTION

Implementation of a longitudinal curriculum for training in advanced communications skills represents an unmet need in most German medical faculties, especially in the 4rth and 5th years of medical studies. The CoMeD project (communication in medical education Düsseldorf) attempted to establish an interdisciplinary program to teach and to assess communicative competence in the 4th academic year. In this paper, we describe the development of the project and report results of its evaluation by medical students.

METHODS

Teaching objectives and lesson formats were developed in a multistage process. A teaching program for simulated patients (SP) was built up and continuous lecturer trainings were estabilshed. Several clinical disciplines co-operated for the purpose of integrating the communication training into the pre-existing clinical teaching curriculum. The CoMeD project was evaluated using feedback-forms after each course.

RESULTS

Until now, six training units for especially challenging communication tasks like "dealing with aggression" or "breaking bad news" were implemented, each unit connected with a preliminary tutorial or e-learning course. An OSCE (objective structured clinical examination) with 4 stations was introduced. The students' evaluation of the six CoMeD training units showed the top or second-best rating in more than 80% of the answers.

DISCUSSION

Introducing an interdisciplinary communication training and a corresponding OSCE into the 4th year medical curriculum is feasible. Embedding communication teaching in a clinical context and involvement of clinicians as lecturers seem to be important factors for ensuring practical relevance and achieving high acceptance by medical students.

Mesenteric lymphangitis and sepsis due to RTX toxin-producing Actinobacillus spp in 2 foals with hypothyroidism-dysmaturity syndrome

Actinobacillus suis-like organisms (ASLOs) have been isolated from the genital, respiratory, and digestive tracts of healthy adult horses, horses with respiratory disease, and septic foals. Two foals with congenital hypothyroidism-dysmaturity syndrome from separate farms developed ASLO infection. At necropsy, both had contracted carpal flexor tendons, thyroid hyperplasia, and thrombotic and necrotizing mesenteric lymphangitis and lymphadenitis; one foal also had mandibular prognathism. Numerous ASLOs were isolated from tissues from both foals, including intestine. Biochemical testing and mass spectrometric analysis of the two Actinobacillus isolates did not allow unequivocal identification. Comparative genetic analysis was done on these and similar isolates, including phylogeny based on 16S rRNA, rpoB and recN genes, as well as RTX (repeat in toxin) toxin typing of apxIA-apxIVA and aqxA genes. One isolate was identified as Actinobacillus suis sensu stricto, based on the presence of apxIA and apxIIA but not aqxA, whereas the other isolate had aqxA but neither apxIA nor apxIIA, consistent with A equuli ssp haemolyticus. Based on genotypic analysis of the isolates included for comparison, 3 of 3 equine ASLOs and 2 of 5 A equuli isolates were reclassified as A equuli subsp haemolyticus, emphasizing the importance of toxin genotyping in accurate classification of actinobacilli.

Binding of a N,N'-bisheteryl derivative of dispirotripiperazine to heparan sulfate residues on the cell surface specifically prevents infection of viruses from different families

N,N'-bisheteryl derivatives of dispirotripiperazine (DSTP) are a novel class of antiviral compounds with some of their representatives very effectively inhibiting the replication of herpes simplex virus type 1 (HSV-1) in cell culture. Using one representative of these compounds, the N,N'-bis(1-oxido[1,2,5]oxadiazolo[3,4-d]pyrimidin-7-yl)-3,12-diaza-6,9-diazonia(5,2,5,2)dispirohexadecane dichloride (DSTP 27), we here further tried to elucidate the molecular mechanisms responsible for the antiviral activity. The results from plaque reduction assays under a variety of conditions suggest that inhibition of HSV-1 strain Kupka replication by DSTP 27 occurs at the level of viral attachment by blockade of heparan sulfate (HS) structures on the cell surface that are used as viral receptors. In contrast to heparin and pentosan polysulfate, pretreatment of cells with DSTP 27 resulted in efficient inhibition of viral adsorption and replication persisting several hours after removal of the inhibitor. Specific binding of DSTP 27 to heparin was demonstrated in vitro. Titrations of gC-positive and gC-negative pseudorabies virus (PrV) mutants on HS-positive and HS-negative cell lines confirmed that inhibitory action of DSTP 27 is strictly HS dependent. Aside from HSV-1 Kupka and PrV, DSTP 27 efficiently inhibits growth of several HSV-1 and HSV-2 strains, among them aciclovir/foscarnet-resistant strains, human cytomegalovirus, human respiratory syncytial virus, and human immunodeficiency viruses known to attach to the cell surface via HS.

Chimeric bovine respiratory syncytial virus with attachment and fusion glycoproteins replaced by bovine parainfluenza virus type 3 hemagglutinin-neuraminidase and fusion proteins

Chimeric bovine respiratory syncytial viruses (BRSV) expressing glycoproteins of bovine parainfluenza virus type 3 (BPIV-3) instead of BRSV glycoproteins were generated from cDNA. In the BRSV antigenome cDNA, the open reading frames of the major BRSV glycoproteins, attachment protein G and fusion protein F, were replaced individually or together by those of the BPIV-3 hemagglutinin-neuraminidase (HN) and/or fusion (F) glycoproteins. Recombinant virus could not be recovered from cDNA when the BRSV F open reading frame was replaced by the BPIV-3 F open reading frame. However, cDNA recovery of the chimeric virus rBRSV-HNF, with both glycoproteins replaced simultaneously, and of the chimeric virus rBRSV-HN, with the BRSV G protein replaced by BPIV-3 HN, was successful. The replication rates of both chimeras were similar to that of standard rBRSV. Moreover, rBRSV-HNF was neutralized by antibodies specific for BPIV-3, but not by antibodies specific to BRSV, demonstrating that the BRSV glycoproteins can be functionally replaced by BPIV-3 glycoproteins. In contrast, rBRSV-HN was neutralized by BRSV-specific antisera, but not by BPIV-3 specific sera, showing that infection of rBRSV-HN is mediated by BRSV F. Hemadsorption of cells infected with rBRSV-HNF and rBRSV-HN proved that BPIV-3 HN protein expressed by rBRSV is functional. Colocalization of the BPIV-3 glycoproteins with BRSV M protein was demonstrated by confocal laser scan microscopy. Moreover, protein analysis revealed that the BPIV-3 glycoproteins were present in chimeric virions. Taken together, these data indicate that the heterologous glycoproteins were not only expressed but were incorporated into the envelope of recombinant BRSV. Thus, the envelope glycoproteins derived from a member of the Respirovirus genus can together functionally replace their homologs in a Pneumovirus background.

Improvement of agitation and anxiety in demented patients after psychoeducative group intervention with their caregivers

OBJECTIVES

It has been convincingly demonstrated that in dementia, psychoeducative group intervention with caregivers positively impacts on motivation for care and satisfaction of the caregivers. It has, however, been neglected to examine the effect of psychoeducative group intervention on the behavioural and psychological symptoms of the demented patients.

METHODS

In a 3-month, expert-based and conceptualized group intervention with caregiving relatives of demented patients we investigated whether behavioural and psychological symptoms may improve and which of a set of independent variables may predict improvement.

RESULTS

The 3-month group intervention yielded a significant improvement in agitation and anxiety of the demented patients. The presence of an additional somatic disease in the patients and male gender predicted a less positive outcome of the intervention related to the presence of agitation.

CONCLUSIONS

This study demonstrated that psychoeducative group intervention with the caregivers of demented patients is helpful for the demented patients themselves. This evidence of a positive mediator effect of the group intervention on the behavioural and psychological symptoms of the patients underscores the importance of nonpharmacological strategies in the treatment of dementia.

Effects of truncation of the carboxy terminus of pseudorabies virus glycoprotein B on infectivity

Glycoproteins homologous to the type I membrane glycoprotein B (gB) of herpes simplex virus 1 (HSV-1) are the most highly conserved glycoproteins within the family Herpesviridae and are present in members of each herpesvirus subfamily. In the alphaherpesvirus pseudorabies virus (PrV), gB is required for entry into target cells and for direct viral cell-to-cell spread. These processes, though related, appear to be distinct, and thus it was interesting to analyze whether they require different functions of gB. To this end, we established cell lines stably expressing different carboxy-terminally truncated versions of PrV gB by deleting either (i) one predicted intracytoplasmic alpha-helical domain encompassing putative YQRL and dileucine internalization signals, (ii) two predicted intracytoplasmic alpha-helical domains, (iii) the complete intracytoplasmic domain, or (iv) the intracytoplasmic domain and the transmembrane anchor region. Confocal laser scanning microscopy showed that gB derivatives lacking at least the last 29 amino acids (aa) localize close to the plasma membrane, while the full-length protein accumulates in intracellular aggregations. Trans-complementation studies with a gB-deleted PrV (PrV-gB(-)) demonstrated that the 29-aa truncated form lacking the putative internalization signals and the C-terminal alpha-helical domain (gB-008) was efficiently incorporated into PrV-gB(-) virions and efficiently complemented infectivity and cell-to-cell spread. Moreover, gB-008 exhibited an enhanced fusogenic activity. In contrast, gB proteins lacking both alpha-helical domains (gB-007), the complete intracytoplasmic domain, or the intracytoplasmic domain and transmembrane anchor were only inefficiently or not at all incorporated into PrV-gB(-) virions and did not complement infectivity. However, gB-007 was able to mediate cell-to-cell spread of PrV-gB(-). Similar phenotypes were observed when virus recombinants expressing gB-008 or gB-007, respectively, instead of wild-type gB were isolated and analyzed. Thus, our data show that internalization of gB is not required for gB incorporation into virions nor for its function in either entry or cell-to-cell spread. Moreover, they indicate different requirements for gB in these membrane fusion processes.

[Improvement of agitation and anxiety in dementia patients after psychoeducative training of their caregivers]

It has been convincingly demonstrated that in dementia psycho-educative training of caregivers positively impacts on motivation for care and satisfaction of the caregivers. It has, however, been neglected to examine the effect of psycho-educative training on the behavioural and psychological symptoms of dementia sufferers. In a three-month, expert-based and conceptualized group intervention with caregiving relatives of demented patients we investigated, whether functional impairment and behavioural and psychological symptoms may improve, which of a set of independent variables may predict improvement, and how the group intervention will be appreciated by the caregivers. The group intervention yielded a significant improvement of memory-related functions in daily living and a significant decrease of agitation and anxiety of the demented patients. The presence of an additional somatic disease predicted worse outcome of the intervention with respect to the impairment of memory-related functions in daily living and of agitation. Anonymous inquiry of the caregivers with respect to their judgement of the intervention revealed high acceptance and appreciation. This study demonstrated that a psycho-educative group intervention with caregiving relatives of dementia sufferers is helpful for both the caregivers and the demented patient. This evidence of a positive mediate effect of the group intervention on the functional and behavioural impairment of the demented patients underscores the importance of nonpharmacological strategies in the treatment plan of dementia.

Infection of Chinese hamster ovary cells by pseudorabies virus

Chinese hamster ovary (CHO) cells have recently been used for identification of receptors for several alphaherpesviruses, including pseudorabies virus (PrV) (R. J. Geraghty, C. Krummenacher, G. H. Cohen, R. J. Eisenberg, and P. G. Spear, Science 280:1618-1620, 1998). The experiments were based on the fact that CHO cells are inefficient target cells for PrV. However, a detailed analysis of the interaction between PrV and CHO wild-type and recombinant PrV-receptor bearing cells has not been performed. We show here that PrV has a growth defect on CHO cells which leads to a ca. 100-fold reduction in plating efficiency, strongly delayed penetration kinetics, and a 10(4)-fold reduction in one-step growth. Entry of PrV into CHO cells is significantly delayed but is not affected by inhibitors of endocytosis, suggesting that the mechanism of penetration resembles that on permissive cells. The defects in plating efficiency and penetration could be corrected by expression of herpesvirus entry mediators B (HveB), HveC, or HveD, with HveC being the most effective. However, the defects in one-step growth and plaque formation were not corrected by expression of PrV receptors, indicating an additional restriction in viral replication after entry. Surprisingly, PrV infection of CHO cells was sensitive to neutralization by a gB-specific monoclonal antibody, which does not inhibit PrV infection of other host cells. Moreover, the same monoclonal antibody neutralized PrV infectivity on cells displaying the interference phenomenon by overexpression of gD and subsequent intracellular sequestration of gD receptors. Thus, absence of gD receptors on two different host cells leads to an increased sensitivity of PrV toward gB neutralization. We hypothesize that this is due to the increased requirement for interaction of gB with a cellular surface protein in the absence of the gD-gD receptor interaction. As expected, CHO cells are as susceptible as other host cells to infection by PrV gD(-) Pass, an infectious gD-negative PrV mutant. However, PrV gD(-) Pass was also not able to form plaques on CHO cells.

Infectivity of a pseudorabies virus mutant lacking attachment glycoproteins C and D

Initiation of herpesvirus infection requires attachment of virions to the host cell followed by fusion of virion envelope and cellular cytoplasmic membrane during penetration. In several alphaherpesviruses, glycoprotein C (gC) is the primary attachment protein, interacting with cell-surface heparan sulfate proteoglycans. Secondary binding is mediated by gD, which, normally, is also required for penetration. Recently, we described the isolation of a gD-negative infectious pseudorabies virus (PrV) mutant, PrV gD- Pass (J. Schmidt, B. G. Klupp, A. Karger, and T. C. Mettenleiter, J. Virol. 71:17-24, 1997). In PrV gD- Pass, attachment and penetration occur in the absence of gD. To assess the importance of specific attachment for infectivity of PrV gD- Pass, the gene encoding gC was deleted, resulting in mutant PrV gCD- Pass. Deletion of both known attachment proteins reduced specific infectivity compared to wild-type PrV by more than 10,000-fold. Surprisingly, the virus mutant still retained significant infectivity and could be propagated on normal noncomplementing cells, indicating the presence of another receptor-binding virion protein. Selection of bovine kidney (MDBK) cells resistant to infection by PrV gCD- Pass resulted in the isolation of a cell clone, designated NB, which was susceptible to infection by wild-type PrV but refractory to infection by either PrV gCD- Pass or PrV gD- Pass, a defect which could partially be overcome by polyethylene glycol (PEG)-induced membrane fusion. However, even after PEG-induced infection plaque formation of PrV gCD- Pass or PrV gD- Pass did not ensue in NB cells. Also, phenotypic gD complementation of PrV gCD- Pass or PrV gD- Pass rescued the defect in infection of NB cells but did not restore plaque formation. Glycosaminoglycan analyses of MDBK and NB cells yielded identical results, and NB cells were normally susceptible to infection by other alphaherpesviruses as well as vesicular stomatitis virus. Infectious center assays after PEG-induced infection of NB cells with PrV gD- Pass on MDBK cells indicated efficient exit of virions from infected NB cells. Together, our data suggest the presence of another receptor and receptor-binding virion protein which can mediate PrV entry and cell-to-cell spread in MDBK cells.

Simple and rapid purification of alphaherpesviruses by chromatography on a cation exchange membrane

A simple and rapid method is described for the purification of two alphaherpesviruses, pseudorabies virus (PrV) and bovine herpesvirus 1, by chromatography on a cation exchange membrane. Cell culture supernatants were passed over a sulfonic-acid modified filter membrane and virions were eluted with a potassium chloride-containing buffer. Over 85% of the virus was eluted within a single fraction and specific infectivity of the resulting virus preparation was over 10-fold higher than that of sucrose gradient-purified virions. Cation exchange was also used for purification of PrV mutants deleted in several glycoproteins which grow in cell culture to titers 10- to 100-fold lower than those obtained by wildtype PrV. For PrV, the presence of non-essential glycoprotein gC, which mediates interaction of virions with cell surface heparin sulfate during attachment, was crucial for the successful purification by cation exchange.

[Assisted suicide in dementia. Ethical considerations between paternalism and autonomy]

This article discusses the problem of euthanasia presenting the case of an 82-year-old man with progressive dementia. Difficulties encountered during daily clinical work are described and analysed, in order to clarify decisions on ethical, legal and professional medical grounds. General decisions concerning life-sustaining measures may be qualitatively improved if the situation of the individual is constantly assessed and considered within the treatment process.

Bovine herpesvirus 1 glycoprotein B does not productively interact with cell surface heparan sulfate in a pseudorabies virion background

Attachment to cell surface heparan sulfate proteoglycans is the first step in infection by several alphaherpesviruses. This interaction is primarily mediated by virion glycoprotein C (gC). In herpes simplex virus, in the absence of the nonessential gC, heparan sulfate binding is effected by glycoprotein B. In contrast, gC-negative pseudorabies virus (PrV) infects target cells via a heparan sulfate-independent mechanism, indicating that PrV virion gB does not productively interact with heparan sulfate. To assay whether a heterologous alphaherpesvirus gB protein will confer productive heparan sulfate binding on gC-negative PrV, gC was deleted from an infectious PrV recombinant, PrV-9112C2, which expresses bovine herpesvirus 1 (BHV-1) gB instead of PrV gB. Our data show that gC-negative PrV-BHV-1 gB recombinant 9112C2-delta gCbeta was not inhibited in infection by soluble heparin, in contrast to the gC-positive parental strain. Similar results were obtained when wild-type BHV-1 was compared with a gC-negative BHV-1 mutant. Moreover, infection of cells proficient or deficient in heparan sulfate biosynthesis occurred with equal efficiency by PrV-9112C2-delta gCbeta, whereas heparan sulfate-positive cells showed an approximately fivefold higher plating efficiency than heparan sulfate-negative cells with the parental gC-positive virus. In summary, our data show that in a PrV gC-negative virion background, BHV-1 gB is not able to mediate infection by productive interaction with heparan sulfate, and they indicate the same lack of heparin interaction for BHV-1 gB in gC-negative BHV-1.

High-level expression of the retinoic acid receptor beta gene in normal cells of the uterine cervix is regulated by the retinoic acid receptor alpha and is abnormally down-regulated in cervical carcinoma cells

Retinoic acid (RA) is essential for regulation of epithelial cell differentiation. The intracellular effects of RA are mediated by RA-binding nuclear receptors, including the RA receptors (RARs) alpha, beta, and gamma. The ligand-activated receptors induce the transcription of target genes by binding to RA-responsive elements in the promoter regions. One target gene is the RAR beta gene, which encodes a potential tumor suppressor. Loss of RA inducibility of RAR beta gene expression is assumed to play a role in the development of several types of human carcinomas, including carcinomas of the uterine cervix. We have analyzed RAR beta gene expression in normal cervical cells and in cervical carcinoma cell lines. The results show that the RAR beta mRNA levels are high and RA inducible in the primary keratinocytes, whereas they are low and not inducible or only slightly inducible by RA in all of the cervical carcinoma cell lines analyzed. The basal and the RA-induced RAR beta mRNA levels tend to increase with senescence of the normal cells. Fusion of primary ectocervical keratinocytes with HeLa cervical carcinoma cells revealed that the characteristics of RAR beta gene expression of the normal cells are dominant over that of the tumor cells. Using synthetic retinoids with receptor-preferential agonist activities and a RAR alpha-specific antagonist, we show that RAR alpha is the major endogenous RAR subtype for induction of RA-dependent RAR beta gene expression. Taken together, our results indicate that abnormal downregulation of RAR beta gene expression may be an important step in the multifactorial process of cervical carcinogenesis.

Ultrastructural analysis of the replication cycle of pseudorabies virus in cell culture: a reassessment

We reinvestigated major steps in the replicative cycle of pseudorabies virus (PrV) by electron microscopy of infected cultured cells. Virions attached to the cell surface were found in two distinct stages, with a distance of 12 to 14 nm or 6 to 8 nm between virion envelope and cell surface, respectively. After fusion of virion envelope and cell membrane, immunogold labeling using a monoclonal antibody against the envelope glycoprotein gE demonstrated a rapid drift of gE from the fusion site, indicating significant lateral movement of viral glycoproteins during or immediately after the fusion event. Naked nucleocapsids in the cytoplasm frequently appeared close to microtubules prior to transport to nuclear pores. At the nuclear pore, nucleocapsids invariably were oriented with one vertex pointing to the central granulum at a distance of about 40 nm and viral DNA appeared to be released via the vertex region into the nucleoplasm. Intranuclear maturation followed the typical herpesvirus nucleocapsid morphogenesis pathway. Regarding egress, our observations indicate that primary envelopment of nucleocapsids occurred at the inner leaflet of the nuclear membrane by budding into the perinuclear cisterna. This nuclear membrane-derived envelope exhibited a smooth surface which contrasts the envelope obtained by putative reenvelopment at tubular vesicles in the Golgi area which is characterized by distinct surface projections. Loss of the primary envelope and release of the nucleocapsid into the cytoplasm appeared to occur by fusion of envelope and outer leaflet of the nuclear membrane. Nucleocapsids were also found engulfed by both lamella of the nuclear membrane. This vesiculation process released nucleocapsids surrounded by two membranes into the cytoplasm. Our data also indicate that fusion between the two membranes then leads to release of naked nucleocapsids in the Golgi area. Egress of virions appeared to occur via transport vesicles containing one or more virus particles by fusion of vesicle and cell membrane. Our data thus support biochemical data and mutant virus studies of (i) two steps of attachment, (ii) the involvement of microtubules in the transport of nucleocapsids to the nuclear pore, and (iii) secondary envelopment in the trans-Golgi area in PrV infection.

Adaptability in herpesviruses: glycoprotein D-independent infectivity of pseudorabies virus

Initial contact between herpesviruses and host cells is mediated by virion envelope glycoproteins which bind to cellular receptors. In several alphaherpesviruses, the nonessential glycoprotein gC has been found to interact with cell surface proteoglycans, whereas the essential glycoprotein gD is involved in stable secondary attachment. In addition, gD is necessary for penetration, which involves fusion between virion envelope and cellular cytoplasmic membrane. As opposed to other alphaherpesvirus gD homologs, pseudorabies virus (PrV) gD is not required for direct viral cell-to-cell spread. Therefore, gD- PrV can be passaged in noncomplementing cells by cocultivating infected and noninfected cells. Whereas infectivity was found to be strictly cell associated in early passages, repeated passaging resulted in the appearance of infectivity in the supernatant, finally reaching titers as high as 10(7) PFU/ml (PrV gD- Pass). Filtration experiments indicated that this infectivity was not due to the presence of infected cells, and the absence of gD was verified by Southern and Western blotting and by virus neutralization. Infection of bovine kidney cells constitutively expressing PrV gD interfered with the infectivity of wild-type PrV but did not inhibit that of PrV gD- Pass. Similar results were obtained after passaging of a second PrV mutant, PrV-376, which in addition to gD also lacks gG, gI, and gE. Penetration assays demonstrated that PrV gD- Pass entered cells much more slowly than wild-type PrV. In summary, our data demonstrate the existence of a gD-independent mode of initiation of infection in PrV and indicate that the essential function(s) that gD performs in wild-type PrV infection can be compensated for after passaging. Therefore, regarding the requirement for gD, PrV seems to be intermediate between herpes simplex virus type 1, in which gD is necessary for penetration and cell-to-cell spread, and varicella-zoster virus (VZV), which lacks a gD gene. Our data show that the relevance of an essential protein can change under selective pressure and thus demonstrate a way in which VZV could have evolved from a PrV-like ancestor.

Glycoprotein gH of pseudorabies virus is essential for penetration and propagation in cell culture and in the nervous system of mice

Glycoprotein H (gH) of pseudorabies virus (PrV) is a structural component of the virion and forms a complex with another glycoprotein, gL. For a detailed analysis of the function of PrV gH, we isolated a gH-deficient mutant on trans-complementing gH-expressing cells after insertion of a beta-galactosidase expression cassette into a partially deleted gH gene. The absence of gH did not affect primary or secondary attachment of PrV but the mutant was not infectious. The defect in infectivity could partially be overcome by experimentally induced membrane fusion using PEG, which suggests that gH was necessary for fusion between virion and cellular membranes. After intranasal inoculation into mice, the LD50 of complemented gH- PrV was more than four orders of magnitude higher than that of wild-type PrV. Infection of the respiratory epithelium was much less efficient with complemented gH- PrV as compared with rescued PrV, reflecting the lack of direct cell-to-cell spread. Complemented gH- PrV was able to penetrate into a few trigeminal and sympathetic first order neurons accessible from the nasal cavity, whereas transneuronal transfer in the second order neurons was not observed. In summary, gH is essential for entry and cell-to-cell spread in cell culture, and for propagation in the nervous system of mice. This substantiates the hypothesis that transneuronal spread in vivo and direct cell-to-cell spread in cell culture are governed by similar mechanisms.

Bovine herpesvirus 1 U(s) open reading frame 4 encodes a glycoproteoglycan

Sequence analysis of the short unique (Us) segment of the bovine herpesvirus 1 (BHV-1) genome predicted that the Us open reading frame (ORF) 4 encodes a protein with homology to glycoprotein G (gG) of other alpha-herpesviruses (P. Leung-Tack, J.-C. Audonnet, and M. Riviere, Virology 199:409-421, 1994). RNA analysis showed that the Us ORF4 is contained within two transcripts of 3.5 and 1.8 kb. The 3.5 kb RNA represents a structurally bicistronic RNA which encompasses the Us ORF3 and Us ORF4, whereas the 1.8-kb RNA constitutes the monocistronic Us ORF4 mRNA. To identify the predicted BHV-I gG, recombinant vaccinia virus expressing the Us ORF4 was used to raise specific antibodies in rabbits. The antiserum recognized a 65-kDa polypeptide and a very diffusely migrating species of proteins with an apparent molecular mass of between 90 and greater than 240 kDa in supernatants of BHV-1-infected cells which was also precipitated together with 61- and 70-kDa polypeptides from cell-associated proteins. The specificity of the reaction was demonstrated by the absence of these proteins from the supernatant of cells infected with the Us ORF4 deletion mutant BHV-l/gp1-8. Treatment of the immunoprecipitated proteins with glycosidases and chondroitinase AC showed that the 65-kDa protein constitutes gG, which contains both N- and O-linked carbohydrates, and that the high-molecular-mass proteins contain glycosaminoglycans linked to a 65-kDa glycoprotein that is antigenically related to gG. These molecules were therefore named glycoproteoglycan C (gpgG). Pulse chase experiments indicated that gG and gpgG were processed from a common precursor molecule with an apparent molecular mass of 61 kDa via a 70-kDa intermediate. Both gG and gpgG could not be found associated with purified virions. In summary, our results identify the BHV-I gG protein and demonstrate the presence of a form of posttranslational modification, glycosamino-glycosylation, that has not yet been described for a herpesvirus-encoded protein.

Identification of cell surface molecules that interact with pseudorabies virus

The alphaherpesvirus pseudorabies virus (PrV) has been shown to attach to cells by interaction between the viral glycoprotein gC and cell membrane proteoglycans carrying heparan sulfate chains (HSPGs). A secondary binding step requires gD and presumably another, hitherto unidentified cellular receptor. By use of a virus overlay protein binding assay (VOPBA), cosedimentation analyses, and affinity chromatography, we identified three species of cell membrane constituents that bind PrV. By treatment with EDTA, peripheral HSPGs of very high apparent molecular mass (>200 kDa) could be extracted from Madin-Darby bovine kidney cells. Binding of PrV to these HSPGs in the VOPBA was sensitive to enzymatic digestion with heparinase or papain. Cosedimentation analyses indicated that binding between PrV and high-molecular-weight HSPG depended on the presence of gC in the virion. In addition, adsorption of radiolabeled PrV virions to cells could be inhibited by the addition of purified high-molecular-weight HSPG. By using urea extraction buffer, a second species of HSPG of approximately 140 kDa could be solubilized. Binding of PrV to this HSPG in the VOPBA was also dependent on the presence of heparan sulfate, since reactivity was abolished after suppression of glycosaminoglycan biosynthesis with NaClO3 and after heparinase treatment. In addition to HSPG, in cellular membrane extracts obtained by treatment with mild detergent, a 85-kDa membrane protein was demonstrated to bind PrV in the VOPBA and affinity chromatography. In summary, we identified three species of cell membrane constituents that bind PrV: a peripheral HSPG of high molecular weight, an integral HSPG of approximately 140 kDa, and an integral membrane protein of 85 kDa. It is tempting to speculate that interaction between PrV and the two species of HSPG mediates primary attachment of PrV and that the 85-kDa protein is involved in a subsequent attachment step.

Cell surface proteoglycans are not essential for infection by pseudorabies virus

Cell surface proteoglycans, in particular those carrying heparan sulfate glycosaminoglycans, play a major role in primary attachment of herpesviruses to target cells. In pseudorabies virus (PrV), glycoprotein gC has been shown to represent the major heparan sulfate-binding virion envelope protein (T. C. Mettenleiter, L. Zsak, F. Zuckermann, N. Sugg, H. Kern, and T. Ben-Porat, J. Virol. 64:278-286, 1990). Since PrV gC is nonessential for viral infectivity in vitro and in vivo, either the interaction between virion envelope and cellular heparan sulfate is not necessary to mediate infection or other virion envelope proteins can substitute as heparan sulfate-binding components in the absence of gC. To answer these questions, we analyzed the infectivity of isogenic gC+ and gC- PrV on mouse L-cell derivatives with defects in glycosaminoglycan biosynthesis, using a rapid and sensitive fluorescence-based beta-galactosidase assay and single-cell counting in a fluorescence-activated cell sorter. Our data show that (i) in the virion, glycoprotein gC represents the only proteoglycan-binding envelope protein, and (ii) cellular proteoglycans are not essential for infectivity of PrV. Attachment studies using radiolabeled virions lacking either gC or the essential gD confirmed these results and demonstrated that PrV gD mainly contributes to binding of Pr virions to cell surface components other than proteoglycans. These data demonstrate the presence of a proteoglycan-independent mode of attachment for Pr virions leading to infectious entry into target cells.

Identification and characterization of a novel structural glycoprotein in pseudorabies virus, gL

Herpesvirus envelope glycoproteins play important roles in the interaction between virions and target cells. In the alphaherpesvirus pseudorabies virus (PrV), seven glycoproteins that all constitute homologs of glycoproteins found in herpes simplex virus type 1 (HSV-1) have been characterized, including a homolog of HSV-1 glycoprotein H (gH). Since HSV-1 gH is found associated with another essential glycoprotein, gL, we analyzed whether PrV also encodes a gL homolog. DNA sequence analysis of a corresponding part of the UL region adjacent to the internal inverted repeat in PrV strains Kaplan and Becker revealed the presence of two open reading frames (ORF). Deduced proteins exhibited homology to uracil-DNA glycosylase encoded by HSV-1 ORF UL2 (54% identity) and gL encoded by HSV-1 ORF UL1 (24% identity), respectively. To identify the PrV UL1 protein, rabbit antisera were prepared against two synthetic oligopeptides that were predicted by computer analysis to encompass antigenic epitopes. Sera against both peptides reacted in Western blots of purified virions with a 20-kDa protein. The specificity of the reaction was demonstrated by peptide competition. Since the PrV UL1 sequence did not reveal the presence of a consensus N-linked glycosylation site, concanavalin A affinity chromatography and enzymatic deglycosylation of virion glycoproteins were used to ascertain that the PrV UL1 product is O glycosylated. Therefore, we designated this protein PrV gL. Analysis of mutant PrV virions lacking gH showed that concomitantly with the absence of gH, gL was also missing in purified virions. In summary, we identified and characterized a novel structural PrV glycoprotein, gL, which represents the eighth PrV glycoprotein described. In addition, we show that virion location of PrV gL is dependent on the presence of PrV gH.

Glycoproteins gIII and gp50 play dominant roles in the biphasic attachment of pseudorabies virus

Virus infections are initiated by adsorption of virions to target cells. This step is mediated by viral attachment proteins that interact with specific cellular receptors. It has previously been shown that the alphaherpesvirus pseudorabies virus (PrV) attaches to cells by way of a process that involves the viral envelope glycoprotein gIII (gC) and a heparin-like cellular surface moiety (T. C. Mettenleiter, L. Zsak, F. Zuckermann, N. Sugg, H. Kern, and T. Ben-Porat (1990) J. Virol. 64, 278-286). To gain further insight into adsorption of PrV different incubation protocols and an isogenic set of glycoprotein deletion mutants were analyzed. Here we show that attachment of wildtype PrV to target cells can be divided into three distinct stages: After primary adsorption, virus cannot be removed by a thorough wash with PBS but can be displaced by exogenous heparin defining a heparin-sensitive adsorption step. This primary adsorption at 0 degrees converts with a half-time of approximately 20 min into a heparin-resistant binding where attached virus is no longer sensitive to exogenous heparin. The presence of heparin during the adsorption process leads to a heparin-independent basal virus binding to cells. Analysis of null mutants in six PrV glycoproteins confirmed that the nonessential glycoprotein gIII (gC) is a major determinant of primary adsorption. The presence of both gIII and the essential glycoprotein gp50 (gD) was shown to be critical for heparin-resistant binding. The importance of gp50 for this process was demonstrated in two isogenic wildtype PrV and gp50- mutant pairs. Similar results were obtained with a mutant bovine herpesvirus 1 lacking the gD-homologous glycoprotein gIV, indicating a general role for the gD-homologous proteins in stable attachment of alphaherpesviruses. Since the gD-homologs are also involved in penetration they might link the processes of viral attachment and entry.

2,3,7,8-Tetrachlorodibenzo-p-dioxin and ethinylestradiol as co-mitogens in cultured rat hepatocytes

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) acts as a potent liver tumor promoter in female but not in male rats. As a basis for studying mechanisms of growth control by liver tumor promoters, the effects of TCDD, of two congeners and ethinylestradiol have been examined in primary cultures of hepatocytes. The agents alone were relatively ineffective but acted as co-mitogens when DNA synthesis was stimulated by epidermal growth factor (EGF). The co-mitogenic effect of TCDD was only observed in adult animals, which are less sensitive to EGF than juvenile animals. Similar effects were seen with two TCDD congeners (1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin and octachlorodibenzo-p-dioxin) in the rank order of their affinity to the Ah receptor. The concentration maximum required for their co-mitogenic action (3 x 10(-12) M for TCDD) was lower than that required for enzyme induction. TCDD was not able to overcome the inhibitory action of TGF-beta (1 ng/ml). Ethinylestradiol additively or even synergistically increased the effect of TCDD. The results suggest: (i) co-mitogenic actions of TCDD and congeners are mediated by the Ah receptor. They are elicited at lower concentrations than those required for the induction of drug-metabolizing enzymes. (ii) Estrogens enhance the co-mitogenic actions of dioxins.