Comparing Synchronous and Asynchronous Task Delivery in Mixed Reality Environments

Asynchronous digital communication is a widely applied and well-known form of information exchange. Most pieces of technology make use of some variation of asynchronous communication systems, be it messaging or email applications. This allows recipients to process digital messages immediately (synchronous) or whenever they have time (asynchronous), meaning that purely digital interruptions can be mitigated easily. Mixed Reality systems have the potential to not only handle digital interruptions but also interruptions in physical space, e.g., caused by co-workers in workspaces or learning environments. However, the benefits of such systems previously remained untested in the context of Mixed Reality. We conducted a user study ($\mathrm{N}=26$) to investigate the impact that the timing of task delivery has on the participants' performance, workflow, and emotional state. Participants had to perform several cognitively demanding tasks in a Mixed Reality workspace. Inside the virtual workspace, we simulated in-person task delivery either during tasks (i.e., interrupting the participant) or between tasks (i.e., delaying the interruption). Our results show that delaying interruptions has a significant impact on subjective metrics like the perceived performance and workload.

Modeling multiple sclerosis using mobile and wearable sensor data

Multiple sclerosis (MS) is a neurological disease of the central nervous system that is the leading cause of non-traumatic disability in young adults. Clinical laboratory tests and neuroimaging studies are the standard methods to diagnose and monitor MS. However, due to infrequent clinic visits, it is fundamental to identify remote and frequent approaches for monitoring MS, which enable timely diagnosis, early access to treatment, and slowing down disease progression. In this work, we investigate the most reliable, clinically useful, and available features derived from mobile and wearable devices as well as their ability to distinguish people with MS (PwMS) from healthy controls, recognize MS disability and fatigue levels. To this end, we formalize clinical knowledge and derive behavioral markers to characterize MS. We evaluate our approach on a dataset we collected from 55 PwMS and 24 healthy controls for a total of 489 days conducted in free-living conditions. The dataset contains wearable sensor data - e.g., heart rate - collected using an arm-worn device, smartphone data - e.g., phone locks - collected through a mobile application, patient health records - e.g., MS type - obtained from the hospital, and self-reports - e.g., fatigue level - collected using validated questionnaires administered via the mobile application. Our results demonstrate the feasibility of using features derived from mobile and wearable sensors to monitor MS. Our findings open up opportunities for continuous monitoring of MS in free-living conditions and can be used to evaluate and guide the effectiveness of treatments, manage the disease, and identify participants for clinical trials.

Meaningful digital biomarkers derived from wearable sensors to predict daily fatigue in multiple sclerosis patients and healthy controls

Fatigue is the most common symptom among multiple sclerosis (MS) patients and severely affects the quality of life. We investigate how perceived fatigue can be predicted using biomarkers collected from an arm-worn wearable sensor for MS patients (n = 51) and a healthy control group (n = 23) at an unprecedented time resolution of more than five times per day. On average, during our two-week study, participants reported their level of fatigue 51 times totaling more than 3,700 data points. Using interpretable generalized additive models, we find that increased physical activity, heart rate, sympathetic activity, and parasympathetic activity while awake and asleep relate to perceived fatigue throughout the day-partly affected by dysfunction of the ANS. We believe our analysis opens up new research opportunities for fine-grained modeling of perceived fatigue based on passively collected physiological signals using wearables-for MS patients and healthy controls alike.

Video-based sympathetic arousal assessment via peripheral blood flow estimation

Electrodermal activity (EDA) is considered a standard marker of sympathetic activity. However, traditional EDA measurement requires electrodes in steady contact with the skin. Can sympathetic arousal be measured using only an optical sensor, such as an RGB camera? This paper presents a novel approach to infer sympathetic arousal by measuring the peripheral blood flow on the face or hand optically. We contribute a self-recorded dataset of 21 participants, comprising synchronized videos of participants' faces and palms and gold-standard EDA and photoplethysmography (PPG) signals. Our results show that we can measure peripheral sympathetic responses that closely correlate with the ground truth EDA. We obtain median correlations of 0.57 to 0.63 between our inferred signals and the ground truth EDA using only videos of the participants' palms or foreheads or PPG signals from the foreheads or fingers. We also show that sympathetic arousal is best inferred from the forehead, finger, or palm.

Controllers or Bare Hands? A Controlled Evaluation of Input Techniques on Interaction Performance and Exertion in Virtual Reality

Virtual Reality (VR) systems have traditionally required users to operate the user interface with controllers in mid-air. More recent VR systems, however, integrate cameras to track the headset's position inside the environment as well as the user's hands when possible. This allows users to directly interact with virtual content in mid-air just by reaching out, thus discarding the need for hand-held physical controllers. However, it is unclear which of these two modalities-controller-based or free-hand interaction-is more suitable for efficient input, accurate interaction, and long-term use under reliable tracking conditions. While interacting with hand-held controllers introduces weight, it also requires less finger movement to invoke actions (e.g., pressing a button) and allows users to hold on to a physical object during virtual interaction. In this paper, we investigate the effect of VR input modality (controller vs. free-hand interaction) on physical exertion, agency, task performance, and motor behavior across two mid-air interaction techniques (touch, raycast) and tasks (selection, trajectory-tracing). Participants reported less physical exertion, felt more in control, and were faster and more accurate when using VR controllers compared to free-hand interaction in the raycast setting. Regarding personal preference, participants chose VR controllers for raycast but free-hand interaction for mid-air touch. Our correlation analysis revealed that participants' physical exertion increased with selection speed, quantity of arm motion, variation in motion speed, and bad postures, following ergonomics metrics such as consumed endurance and rapid upper limb assessment. We also found a negative correlation between physical exertion and the participant's sense of agency, and between physical exertion and task accuracy.

Experiencing herd immunity in virtual reality increases COVID-19 vaccination intention: Evidence from a large-scale field intervention study

This study investigates the impact of an immersive virtual reality (VR) simulation of herd immunity on vaccination intentions and its potential underlying mechanisms. In this preregistered field study, N = 654 participants were randomly assigned to one of the three VR conditions: (1) Gamified Herd Immunity; (2) Gamified Herd Immunity + Empathy (with additional narrative elements); (3) Control (gamified with no vaccination-related content). In the Gamified Herd Immunity simulation, participants embodied a vulnerable person and navigated a wedding venue trying to avoid getting infected. A total of 455 participants with below maximum intentions to take a novel vaccine and without severe cybersickness were analyzed. The Gamified Herd Immunity + Empathy and the Gamified Herd Immunity conditions increased vaccination intentions by 6.68 and 7.06 points on a 0-100 scale, respectively, compared to 1.91 for the Control condition. The Gamified Herd Immunity + Empathy condition enhanced empathy significantly more than the Gamified Herd Immunity condition but did not result in higher vaccination intentions. Experienced presence was related to the change in vaccination intentions. The results suggest that VR vaccination communication can effectively increase vaccination intentions; the effect is not solely due to the technological novelty and does not depend on empathy.

Characterizing Physiological Responses to Fear, Frustration, and Insight in Virtual Reality

Physiological sensing often complements studies of human behavior in virtual reality (VR) to detect users' affective and cognitive states. Some psychological states, such as fear and frustration, can be particularly hard to differentiate from a physiological perspective as they are close in the arousal and valence emotional space. Moreover, it is largely unclear how users' physiological reactions are expressed in response to transient psychological states such as fear, frustration, and insight-especially since these are rich indicators for characterizing users' responses to dynamic systems but are hard to capture in highly interactive settings. We conducted a study ($N=24$) to analyze participants' pulmonary, electrodermal, cardiac, and pupillary responses to moments of fear, frustration, and insight in immersive settings. Participants interacted in five VR environments, throughout which we measured their physiological reactions and analyzed the patterns we observed. We also measured subjective fear and frustration using questionnaires. We found differences between fear and frustration pupillary, respiratory, and electrodermal responses, as well as between the pupillary changes that followed fear in a horror game and those that followed fear in a vertigo experiment. We present the relationships between fear levels, frustration levels, and their physiological responses. To detect these affective events and states, we introduce user-independent binary classification models that achieved an average micro $F_{1}$ score of 71% for detecting fear in a horror game, 75% for fear of vertigo, 76% for frustration, and 75% for insight, showing the promise for detecting these states from passive and objective signals.

Continuous monitoring with wearables in multiple sclerosis reveals an association of cardiac autonomic dysfunction with disease severity

Background

Dysfunction of the autonomic nervous system is common in multiple sclerosis patients, and probably present years before diagnosis, but its role in the disease is poorly understood.

Objectives

To study the autonomic nervous system in patients with multiple sclerosis using cardiac autonomic regulation measured with a wearable.

Methods

In a two-week study, we present a method to standardize the measurement of heart rate variability using a wearable sensor that allows the investigation of circadian trends. Using this method, we investigate the relationship of cardiac autonomic dysfunction with clinical hallmarks and subjective burden of fatigue and autonomic symptoms.

Results

In 55 patients with multiple sclerosis and 24 healthy age- and gender-matched controls, we assessed the cumulative circadian heart-rate variability trend of two weeks. The trend analysis revealed an effect of inflammation (P = 0.0490, SMD = -0.5466) and progressive neurodegeneration (P = 0.0016, SMD = 1.1491) on cardiac autonomic function. No association with subjective symptoms could be found.

Conclusions

Trend-based heart rate variability measured with a wearable provides the opportunity for unobtrusive long-term assessment of autonomic functions in patients with multiple sclerosis. It revealed a general dysregulation in patients with multiple sclerosis.

Virtual reality reduces COVID-19 vaccine hesitancy in the wild: a randomized trial

Vaccine hesitancy poses one of the largest threats to global health. Informing people about the collective benefit of vaccination has great potential in increasing vaccination intentions. This research investigates the potential for engaging experiences in immersive virtual reality (VR) to strengthen participants' understanding of community immunity, and therefore, their intention to get vaccinated. In a pre-registered lab-in-the-field intervention study, participants were recruited in a public park (tested: [Formula: see text], analyzed: [Formula: see text]). They were randomly assigned to experience the collective benefit of community immunity in a gamified immersive virtual reality environment ([Formula: see text] of sample), or to receive the same information via text and images ([Formula: see text] of sample). Before and after the intervention, participants indicated their intention to take up a hypothetical vaccine for a new COVID-19 strain (0-100 scale) and belief in vaccination as a collective responsibility (1-7 scale). The study employs a crossover design (participants later received a second treatment), but the primary outcome is the effect of the first treatment on vaccination intention. After the VR treatment, for participants with less-than-maximal vaccination intention, intention increases by 9.3 points (95% CI: 7.0 to [Formula: see text]). The text-and-image treatment raises vaccination intention by 3.3 points (difference in effects: 5.8, 95% CI: 2.0 to [Formula: see text]). The VR treatment also increases collective responsibility by 0.82 points (95% CI: 0.37 to [Formula: see text]). The results suggest that VR interventions are an effective tool for boosting vaccination intention, and that they can be applied "in the wild"-providing a complementary method for vaccine advocacy.

Cognitive fatigability assessment test (cFAST): Development of a new instrument to assess cognitive fatigability and pilot study on its association to perceived fatigue in multiple sclerosis

Background

Fatigue is a common symptom of many diseases, including multiple sclerosis. It manifests as a cognitive or physical condition. Fatigue is poorly understood, and effective therapies are missing. Furthermore, there is a lack of methods to measure fatigue objectively. Fatigability, the measurable decline in performance during a task, has been suggested as a complementary method to quantify fatigue.

Objective

To develop a new and objective measurement of cognitive fatigability and investigate its association with perceived fatigue.

Methods

We introduced the cognitive fatigability assessment test (cFAST), a novel smartphone-based test to quantify cognitive fatigability. Forty-two people with multiple sclerosis (23 fatigued and 19 non-fatigued, defined by the Fatigue Scale for Motor and Cognitive Functions) took part in our validation study. Patients completed cFAST twice. We used t-tests, Monte Carlo sampling, and area under the receiver operating characteristic curves to evaluate our approach using two sets of proposed metrics.

Results

When classifying fatigue, our fatigability metric Δresponse time has a mean area under the receiver operating characteristic curve of 0.74 (95% CI 0.64–0.84), making it the best performing metric for this task. Furthermore, Δresponse time shows a statistically significant difference between the fatigued and non-fatigued groups (t = 2.27, P = .03). Particularly, cognitively-fatigued patients decline in performance, while non-fatigued patients do not.

Conclusions

We introduce cFAST, a new instrument to quantify cognitive fatigability. Our pilot study provides evidence that cognitive fatigability assessment test produces a quantifiable drop in cognitive performance in a short period. Furthermore, our results indicate that cFAST may have the potential to serve as a surrogate for subjective cognitive fatigue. cFAST is significantly shorter than the existing fatigability assessments and does not require specialized equipment. Thus, it could enable frequent and remote monitoring, which could substantially aid clinicians in better understanding and treating fatigue.

Core Data Elements in Acute Myeloid Leukemia: A Unified Medical Language System-Based Semantic Analysis and Experts' Review

Background

For cancer domains such as acute myeloid leukemia (AML), a large set of data elements is obtained from different institutions with heterogeneous data definitions within one patient course. The lack of clinical data harmonization impedes cross-institutional electronic data exchange and future meta-analyses.

Objective

This study aimed to identify and harmonize a semantic core of common data elements (CDEs) in clinical routine and research documentation, based on a systematic metadata analysis of existing documentation models.

Methods

Lists of relevant data items were collected and reviewed by hematologists from two university hospitals regarding routine documentation and several case report forms of clinical trials for AML. In addition, existing registries and international recommendations were included. Data items were coded to medical concepts via the Unified Medical Language System (UMLS) by a physician and reviewed by another physician. On the basis of the coded concepts, the data sources were analyzed for concept overlaps and identification of most frequent concepts. The most frequent concepts were then implemented as data elements in the standardized format of the Operational Data Model by the Clinical Data Interchange Standards Consortium.

Results

A total of 3265 medical concepts were identified, of which 1414 were unique. Among the 1414 unique medical concepts, the 50 most frequent ones cover 26.98% of all concept occurrences within the collected AML documentation. The top 100 concepts represent 39.48% of all concepts’ occurrences. Implementation of CDEs is available on a European research infrastructure and can be downloaded in different formats for reuse in different electronic data capture systems.

Conclusions

Information management is a complex process for research-intense disease entities as AML that is associated with a large set of lab-based diagnostics and different treatment options. Our systematic UMLS-based analysis revealed the existence of a core data set and an exemplary reusable implementation for harmonized data capture is available on an established metadata repository.

Doubling the Signal Quality of Smartphone Camera Pulse Oximetry Using the Display Screen as a Controllable Selective Light Source

Recent smartphones have the potential to bring camera oximetry to everyone using their powerful sensors and the capability to process measurements in real-time, potentially augmenting people's lives through always-available oximetry monitoring everywhere. The challenge of camera oximetry on smartphones is the low contrast between reflections from oxyhemoglobin and deoxyhemoglobin. In this paper, we show that this is the result of using the camera flash for illumination, which illuminates evenly across bands than thus leads to the diminished contrast in reflections. Instead, we propose capturing pulse using the front-facing camera and illuminating with the phone's display, a selective illuminant in the red, green, and blue band. We evaluate the spectral characteristics of the phone display using a spectroradiometer in a controlled experiment, convolve them with the sensitivity curves of the phone's camera, and show that the screen's narrow-band display illumination increases the contrast between the reflections in the desired bands by a factor of two compared to flash illumination. Our preliminary evaluation showed further support for our approach and findings.

Differentiation of Aneugens and Clastogens in the In Vitro Micronucleus Test by Kinetochore Scoring Using Automated Image Analysis

The in vitro micronucleus test according to OECD Test Guideline 487 (TG 487) is widely used to investigate the genotoxic potential of drugs. Besides the identification of in vitro genotoxicants, the assay can be complemented with kinetochore staining for the differentiation between clastogens and aneugens. This differentiation constitutes a major contribution to risk assessment as especially aneugens show a threshold response. Thus, a novel method for automated MN plus kinetochore (k+) scoring by image analysis was developed based on the OECD TG 487. Compound-induced increases in MN frequency can be detected using the cytokinesis-block (cytochalasin B) method in V79 cells after 24 h in a 96-well format. Nuclei, MN, and kinetochores were labeled with nuclear counterstain and anti-kinetochore antibodies, respectively, to score MN in binuclear or multinuclear cells and to differentiate compound-induced MN by the presence of kinetochores. First, a reference data set was created by manual scoring using two clastogens and aneugens. After developing the automated scoring process, a set of 14 reference genotoxicants were studied. The automated image analysis yielded the expected results: 5/5 clastogens and 6/6 aneugens (sensitivity: 100%) as well as 3/3 non-genotoxicants (specificity: 100%) were correctly identified. Further, a threshold was determined for identifying aneugens. Based on the data for our internally characterized reference compounds, unknown compounds that induce ≥53.8% k+ MN are classified as aneugens. The current data demonstrate excellent specificity and sensitivity and the methodology is superior to manual microscopic analysis in terms of speed and throughput as well as the absence of human bias. Environ. Mol. Mutagen. 60:227-242, 2019. © 2018 Wiley Periodicals, Inc.

Novel bioactive from Lactobacillus brevis DSM17250 to stimulate the growth of Staphylococcus epidermidis: a pilot study

Commensal skin microbiota plays an important role in both influencing the immune response of the skin and acting as a barrier against colonisation of potentially pathogenic microorganisms and overgrowth of opportunistic pathogens. Staphylococcus epidermidis is a key constituent of the normal microbiota on human skin. It balances the inflammatory response after skin injury and produces antimicrobial molecules that selectively inhibit skin pathogens. Here we describe Lactobacillus brevis DSM17250 that was identified among hundreds of Lactobacillus strains to exhibit an anti-inflammatory effect in human keratinocytes in vitro and specific stimulatory impact on the growth of S. epidermidis. The aqueous cell-free extract of L. brevis DSM17250 was used in an ointment formulation and tested in a randomized placebo-controlled double blinded human pilot study. Healthy volunteers with diagnosed dry skin were treated for four weeks. The study data shows that L. brevis DSM17250 extract induces re-colonisation of the skin by protective commensal microorganisms as judged from selective bacterial cultivation of surface-associated skin microorganism of the lower leg. Furthermore, the 4 week administration of the L. brevis DSM17250 extract significantly improved the transepidermal water loss value (TEWL), reduced the xerosis cutis symptoms and stinging. The data shows that daily application of L. brevis DSM17250 extract in a topical product significantly improves the microbial skin microbiota by promoting the growth of species which possess beneficial regulatory and protective properties such as S. epidermidis. Restoring the natural skin microbiota leads to significantly improved skin barrier function (as transepidermal water loss) and decrease of xeroderma (xerosis cutis) symptoms (as measured by dry skin area and severity index, DASI). We propose that improving and stabilizing the natural skin microbiota by specifically stimulating the growth of S. epidermidis is an important and novel concept to manage skin diseases associated with microbiota dysbiosis.

Key Data Elements in Myeloid Leukemia

Data standards consisting of key data elements for clinical routine and trial documentation harmonize documentation within and across different health care institutions making documentation more efficient and improving scientific data analysis. This work focusses on the field of myeloid leukemia (ML), where a semantic core of common data elements (CDEs) in routine and trial documentation is established by automatic UMLS-based form analysis of existing documentation models. These CDEs (n = 227) were initially reviewed and commented by leukemia experts before they were systematically surveyed by an international voting process through seven hematologists of four countries. The total agreement score was 86%. 116 elements (51%) of these share an agreement score of 100%. This work generated CDEs with language-independent semantic codes and international clinical expert review to build a first approach towards an international data standard for ML. A first version of the CDE list is implemented in the data standard Operational Data Model and additional other data formats for reuse in different medical information systems.

Specific Lactobacillus/Mutans Streptococcus co-aggregation

Selective interaction of mutans streptococci with benign bacteria could present an opportunity for their removal from the mouth without disruption of other oral flora. This study was conducted to find probiotic lactobacilli that could specifically co-aggregate in vitro with mutans streptococci, but not with other plaque commensals. A search of 624 lactobacilli among a large culture library revealed 6 strains, all classifiable as L. paracasei or L. rhamnosus, which met this criterion. Such novel, specific co-aggregation, however, was not a general characteristic of these species or the genus Lactobacillus. The co-aggregation by these specific lactobacilli was characterized as heat treatment (autoclaving)- and protease-resistant, lectin-independent, not inactivated by sugar substitutes, operational over a wide pH range, unaffected by whole saliva, but calcium-dependent. It is thus seen to present a potential strategy for in vivo alteration of plaque biofilm and caries.

Temperature gradient between brain tissue and arterial blood mirrors the flow-metabolism relationship in uninjured brain: an experimental study

BACKGROUND

The purpose of the present experimental study was to determine the feasibility and usefulness of brain temperature measurement (T(br)) and the calculated difference between brain temperature and arterial blood temperature (DeltaT(br-a)) in uninjured brain during variations of cerebral perfusion pressure (CPP) and concomitant changes of the regional cerebral blood flow (rCBF).

METHODS

Nine anaesthetized pigs were subjected to controlled CPP decrease to assess the lower cerebral autoregulation threshold. A parenchymal intracranial pressure (ICP) sensor combined with a microthermistor for temperature measurement, a miniaturized Clark-type electrode measuring brain tissue oxygenation (p(ti)O(2)), a small flexible intraparenchymal thermodilution probe for measuring rCBF and cerebral microdialysis were inserted carefully in the frontal white matter.

RESULTS

Analysing the p(ti)O(2) during controlled CPP decrease, we found significant breakpoints of p(ti)O(2) at a CPP of 40 mmHg and 20 mmHg, related to an rCBF of 20 ml/100 g/min and approximately 10 ml/100 g/min. Similarly, the relationship between DeltaT(br-a), and CPP or rCBF revealed a characteristic increase of DeltaT(br-a) in the negative direction up to more than -0.30 degrees C assuming a strong flow dependency.

CONCLUSION

The temperature difference between brain tissue and arterial blood DeltaT(br-a) mainly reflects the cerebral blood flow-brain tissue oxygenation-metabolism relationship as far as the estimation of the individual lower cerebral autoregulation threshold.

Local and systemic hemorheological effects of cerebral hyper- and hypoperfusion in a porcine model

Using a well defined pig model, we investigated whether cerebral hypertension and hypotension influence hemorheological factors. After surgical preparation and stabilization, periods of hyperventilation, controlled periods of cerebral perfusion pressure increases and decreases were utilized. After each period, blood samples were collected from the cannulated femoral artery and vein, and from the superior sagittal sinus. Erythrocyte deformability, whole blood and plasma viscosity and hematological parameters were determined. Erythrocyte deformability significantly worsened in arterial samples after hypertension and hypotension, and in sinus samples it was impaired after hypotension period. Hematocrit significantly increased in arterial and sinus samples during hypertensive period, accompanied by similar alterations in whole blood viscosity. We conclude that hemodynamic changes caused by hyperventilation, hyper- or hypotension can influence hemorheological factors, and suggest that the rheological alterations can affect local hemodynamic and metabolic conditions.

Full-genome RNAi profiling of early embryogenesis in Caenorhabditis elegans

A key challenge of functional genomics today is to generate well-annotated data sets that can be interpreted across different platforms and technologies. Large-scale functional genomics data often fail to connect to standard experimental approaches of gene characterization in individual laboratories. Furthermore, a lack of universal annotation standards for phenotypic data sets makes it difficult to compare different screening approaches. Here we address this problem in a screen designed to identify all genes required for the first two rounds of cell division in the Caenorhabditis elegans embryo. We used RNA-mediated interference to target 98% of all genes predicted in the C. elegans genome in combination with differential interference contrast time-lapse microscopy. Through systematic annotation of the resulting movies, we developed a phenotypic profiling system, which shows high correlation with cellular processes and biochemical pathways, thus enabling us to predict new functions for previously uncharacterized genes.

A human cDNA expression library in yeast enriched for open reading frames

We developed a high-throughput technique for the generation of cDNA libraries in the yeast Saccharomyces cerevisiae which enables the selection of cloned cDNA inserts containing open reading frames (ORFs). For direct screening of random-primed cDNA libraries, we have constructed a yeast shuttle/expression vector, the so-called ORF vector pYEXTSH3, which allows the enriched growth of protein expression clones. The selection system is based on the HIS3 marker gene fused to the C terminus of the cDNA insert. The cDNAs cloned in-frame result in histidine prototrophic yeast cells growing on minimal medium, whereas clones bearing the vector without insert or out-of-frame inserts should not grow on this medium. A randomly primed cDNA library from human fetal brain tissue was cloned in this novel vector, and using robot technology the selected clones were arrayed in microtiter plates and were analyzed by sequencing and for protein expression. In the constructed cDNA expression library, about 60% of clones bear an insert in the correct reading frame. In comparison to unselected libraries it was possible to increase the clones with inserts in the correct reading frame more than fourfold, from 14% to 60%. With the expression system described here, we could avoid time-consuming and costly techniques for identification of clones expressing protein by using antibody screening on high-density filters and subsequently rearraying the selected clones in a new "daughter" library. The advantage of this ORF vector is that, in a one-step screening procedure, it allows the generation of expression libraries enriched for clones with correct reading frames as sources of recombinant proteins.

A system for dual protein expression in Pichia pastoris and Escherichia coli

We have constructed a novel Pichia pastoris/Escherichia coli dual expression vector for the production of recombinant proteins in both host systems. In this vector, an E. coli T7 promoter region, including the ribosome binding site from the phage T7 major capsid protein for efficient translation is placed downstream from the yeast alcohol oxidase promoter (AOX). For detection and purification of the target protein, the vector contains an amino-terminal oligohistidine domain (His6) followed by the hemaglutinine epitope (HA) adjacent to the cloning sites. A P. pastoris autonomous replicating sequence (PARS) was integrated enabling simple propagation and recovery of plasmids from yeast and bacteria (1). In the present study, the expression of human proteins in P. pastoris and E. coli was compared using this single expression vector. For this purpose we have subcloned a cDNA expression library deriving from human fetal brain (2) into our dual expression T7 vector and investigated 96 randomly picked clones. After sequencing, 29 clones in the correct reading frame have been identified, their plasmids isolated and shuttled from yeast to bacteria. All proteins were expressed soluble in P. pastoris, whereas in E. coli only 31% could be purified under native conditions. Our data indicates that this dual expression vector allows the economic expression and purification of proteins in different hosts without subcloning.

Endoscopic third ventriculostomy is the treatment of choice for obstructive hydrocephalus due to pediatric pineal tumors

Pineal lesions in the pediatric patient are often complicated by the development of hydrocephalus due to obstruction of the aqueduct or the third ventricle by tumor masses. In such cases, hydrocephalus treatment has the highest priority and should be performed prior to any surgical treatment of the pineal tumor itself. The golden standard in obstructive hydrocephalus treatment remains placement of a temporary or permanent cerebrospinal fluid shunt, although there are many long-term complications associated with a shunt system. To avoid these and to render the patients independent from a failure-prone shunt system, we employed endoscopic third ventriculostomy for permanent relief of elevated intracranial pressure prior to surgical removal of the pineal lesions. The present study summarizes the results of this approach in 7 pediatric patients with obstructive hydrocephalus. No complications of the endoscopic procedure were encountered, and the ventriculostomy remained patent in all cases, as confirmed by motion sensitive MRI. The advantages of endoscopic third ventriculostomy as compared with other techniques are discussed, and its increasing role in the management of children with space occupying lesions of the pineal region is defined.

Intersexual Transfer of a Toxic Terpenoid during Copulation and Its Paternal Allocation to Developmental Stages: Quantification of Cantharidin in Cantharidin-Producing Oedemerids (Coleoptera: Oedemeridae) and Canthariphilous Pyrochroids (Coleoptera: Pyrochroidae)

In whole body extracts of the canthariphilous pyrochroid Schizotus pectinicornis and the cantharidin-producing oedemerid Oedemera femorata cantharidin contents were determined by means of quantitative gas chromatography. Adults and all developmental stages of both species contain this terpenoid, but in considerably different amounts. Cantharidin contents differ significantly between the sexes of adult O. femorata: 8.4 μ,g/female, 3.5 μg/male. Values for Sch. pectinicornis are more than 30-fold lower than those of O. femorata and no intersexual difference in the cantharidin content could be detected. Eggs of O. femorata contained cantharidin and larvae of this species are capable of synthesizing this terpenoid. The total amount of cantharidin increases in successive instars. In Sch. pectinicornis, the content of cantharidin decreases from egg to first instar.

Feeding and copulation experiments with [2H2]cantharidin indicate that in O. femorata no or only very small amounts of cantharidin are transferred from males to females at copulation. Thus, males do not invest in the protection of their offspring by cantharidin gifts to the mate. For Sch. pectinicornis an intersexual transfer of labelled cantharidin during copulation was detected. About 45% of the entire cantharidin content in mated females derived from fed males. Analyses of eggs and first instar larvae show that a paternal allocation of 2[H2]cantharidin to developmental stages exists for this canthariphilous pyrochroid.

[Therapeutical treatment of primiparae to reduce anxieties in connection with pregnancy and delivery (author's transl)]

Two groups of primiparae were subjected to two different forms of basically behavior therapeutic treatments which aimed to reduce birth anxiety. In comparison with an untreated control-group a significant reduction of birth anxieties was found. There was no significant effect between the treatment-groups. Therapeutical success did not depend on anxiety-level before therapy. In relation to behavior during delivery a higher degree of relaxation was only found in the second experimental group.