The PostStroke-Manager - combining mobile, digital and sensor-based technology with personal assistance: protocol of the feasibility study

INTRODUCTION

Post stroke management has moved into the focus as it represents the only way to secure acute treatment effects in the long term. Due to individual courses, post stroke management appears rather challenging and is hindered by existing barriers between treatment sectors. As a novel concept, the PostStroke-Manager combines digital and sensor-based technology with personal assistance to enable intersectoral cooperation, best possible reduction of stroke-related disability, optimal secondary prevention, and detection of physical and psychological comorbidities.

METHODS

This prospective single-center observational study aims to investigate the feasibility of the PostStroke-Manager concept in an outpatient setting. Ninety patients who have suffered an ischemic or hemorrhagic stroke or transient ischemic attack will be equipped with a tablet and mobile devices recording physical activity, blood pressure, and electrocardiographic signals. Through a server-based platform, patients will be connected with the primary care physician, a stroke pilot and, if necessary, other specialists who will use web-based platforms. Via the tablet, patients will have access to an application with 10 newly designed components including, for instance, a communication tool, medication schedule, medical records platform, and psychometric screenings (e.g., depression, anxiety symptoms, quality of life, adherence, cognitive impairment). During the 1-year follow-up period, clinical visits are scheduled at three-month intervals. In the interim, communication will be secured by an appropriate tool that includes text messenger, audio, and video telephony. As the primary endpoint, feasibility will be measured by a 14-item questionnaire that addresses digital components, technical support, and personal assistance. The PostStroke-Manager will be judged feasible if at least 50% of these aspects are rated positively by at least 75% of patients. Secondary endpoints include feedback from professionals and longitudinal analyses on clinical and psychometric parameters.

PERSPECTIVE

This study will answer the question of whether combined digital and personal support is a feasible approach to post stroke management. Furthermore, the patient perspective gained regarding digital support may help to specify future applications. This study will also provide information regarding the potential use of remote therapies and mobile devices in situations with limited face-to-face contacts.

TRIAL REGISTRATION

German Register for Clinical Trials ( DRKS00023213 .), registered 27 April 2021.

Analysis of Biomedical Longitudinal Multisensor Data: Extracting Interpretable Features by Context* *

Longitudinal quotidian acquisition of personal data over weeks and months has been increasingly facilitated in the last few years. Smartwatches and smartphones serve as platforms containing a variety of sensors, able to capture a multitude of individual biomedical and behavioral aspects. This development enables new analytic pathways in medicine and health care. Due to data of this type being increasingly ascertainable, efficient analyses become crucial. For instance, determining meaningful, individualized patterns from such multimodal, longitudinal time series can be very time and resource consuming. To this end, interpretable and robust parameters need to be extracted. In this paper, we explore a general approach to context based parameter estimation and illustrate its ability to be utilized for determining individualized and interpretable biosignal and behavioral patterns.

Analysis of Physiological and Activity Data Specific to Locations Obtained through Geographical Clustering

This paper presents methods for the investigation and visualization of spatial, physical and physiological data acquired by wearable sensors. Several clustering methods and descriptive statistics are combined. Based on graph theory, an individual network was constructed depending on daily physiological and activity data. By using such networks, clusters and day-to-day differences can be utilized to present physiological status and activity. One possible application is the usage of these subject-specific location and activity based influences in diagnostic and therapy such as of cardiac diseases.

Characterization of a folding intermediate from HIV-1 ribonuclease H

The RNase H domain from HIV-1 (HIV RNase H) encodes an essential retroviral activity. Refolding of the isolated HIV RNase H domain shows a kinetic intermediate detectable by stopped-flow far UV circular dichroism and pulse-labeling H/D exchange. In this intermediate, strands 1, 4, and 5 as well as helices A and D appear to be structured. Compared to its homolog from Escherichia coli, the rate limiting step in refolding of HIV RNase H appears closer to the native state. We have modeled this kinetic intermediate using a C-terminal deletion fragment lacking helix E. Like the kinetic intermediate, this variant folds rapidly and shows a decrease in stability. We propose that inhibition of the docking of helix E to this folding intermediate may present a novel strategy for anti HIV-1 therapy.

Lymphotactin is produced by NK cells and attracts both NK cells and T cells in vivo

Injection of lymphotactin (Lptn) into the peritoneum caused an influx of lymphocytes at 24 h. Phenotypic analysis of the cellular influx showed that a large proportion of these cells were T lymphocytes; however, a large number of NK cells was also present. This effect of murine Lptn (mLptn) was specific since the cellular influx was blocked with a mLptn-specific mAb. Similar results were observed when Lptn was injected s.c. and the tissue was analyzed by immunohistochemistry using an anti-CD3epsilon mAb. Microchemotaxis assays confirmed that murine NK cells respond to mLptn, and also showed human NK clones to be similarly responsive to recombinant human Lptn (rhLptn). Immunohistochemical analysis of IL-2-activated murine NK cells and Northern analysis of human NK clones revealed that these cells also produce Lptn, suggesting that a self-regulatory migration mechanism exists in NK cells. Together these data confirm, in vivo, the lymphocyte specificity of Lptn previously observed in vitro and extend its chemotactic effects to the NK cell lineage. We also investigated the functional consequences of truncating the carboxyl terminus of hLptn. This truncated molecule (which is missing the carboxyl-terminal 22 amino acids of hLptn) had no detectable activity on human PBLs. In addition, while hLptn was found to attract murine splenocytes in vitro, the carboxyl-terminal truncated hLptn was again inactive on murine splenocytes. This observation indicates the presence of structural features in the carboxyl terminus of Lptn that are necessary for its biologic activity.

Lymphotactin is produced by NK cells and attracts both NK cells and T cells in vivo

Injection of lymphotactin (Lptn) into the peritoneum caused an influx of lymphocytes at 24 h. Phenotypic analysis of the cellular influx showed that a large proportion of these cells were T lymphocytes; however, a large number of NK cells was also present. This effect of murine Lptn (mLptn) was specific since the cellular influx was blocked with a mLptn-specific mAb. Similar results were observed when Lptn was injected s.c. and the tissue was analyzed by immunohistochemistry using an anti-CD3epsilon mAb. Microchemotaxis assays confirmed that murine NK cells respond to mLptn, and also showed human NK clones to be similarly responsive to recombinant human Lptn (rhLptn). Immunohistochemical analysis of IL-2-activated murine NK cells and Northern analysis of human NK clones revealed that these cells also produce Lptn, suggesting that a self-regulatory migration mechanism exists in NK cells. Together these data confirm, in vivo, the lymphocyte specificity of Lptn previously observed in vitro and extend its chemotactic effects to the NK cell lineage. We also investigated the functional consequences of truncating the carboxyl terminus of hLptn. This truncated molecule (which is missing the carboxyl-terminal 22 amino acids of hLptn) had no detectable activity on human PBLs. In addition, while hLptn was found to attract murine splenocytes in vitro, the carboxyl-terminal truncated hLptn was again inactive on murine splenocytes. This observation indicates the presence of structural features in the carboxyl terminus of Lptn that are necessary for its biologic activity.

Identification of a peptide which binds to the carbohydrate-specific monoclonal antibody B3

The monoclonal antibody (mAb) B3 recognizes an antigen found on the surface of many adenocarcinoma cells. While the structure of the cellular antigen is unknown, epitope mapping using neoglycoproteins with known carbohydrate moieties indicates that the mAb B3 reacts with the LewisY (LeY) antigen [Pastan et al., Cancer Res. 51 (1991) 3781-3787]. We have used mAb B3 to select for peptides that mimic the carbohydrate structure using libraries of filamentous phage displaying random peptides on their surface. Phage that were selected coded for the sequence APWLYGPA. The corresponding peptide was synthesized and tested for its ability to bind to mAb B3. The peptide was found to inhibit specifically the binding of 111In-labeled mAb B3 to A431 adenocarcinoma cells, as well as to inhibit killing of these cells by a B3 immunotoxin. In addition, the LeY carbohydrate, lactodifucotetraose, was able to compete with the phage displaying this peptide for binding to mAb B3. Alanine-scanning mutagenesis of the sequence coding for this peptide indicates that four residues, PWLY, were critical for binding to the mAb. The sequence is similar to other sequences known to mimic carbohydrate structures.

Effect of cholesterol on the uptake and intracellular degradation of liposomes by liver and spleen; a combined biochemical and gamma-ray perturbed angular correlation study

We investigated the effect of cholesterol on the uptake and intracellular degradation of liposomes by rat liver and spleen macrophages. Multilamellar vesicles (MLV) consisting of distearoylphosphatidylcholine/phosphatidylserine (molar ratio 9:1) or distearoylphosphatidylcholine/cholesterol/phosphatidylserine (molar ratio 4:5:1) were labeled with [3H]cholesteryl hexadecyl ether and/or cholesteryl [14C]oleate. After i.v. injection the cholesterol-containing liposomes were eliminated less rapidly from the bloodstream and taken up to a lesser extent by the liver (macrophages) than the cholesterol-free liposomes. Assessment of the 3H/14C ratios in liver and spleen cells revealed that the cholesterol-containing liposomes are substantially more resistant towards intracellular degradation than the cholesterol-free liposomes. These results could be confirmed by measuring the release of 111In from liposomes after uptake by liver and spleen by means of gamma-ray perturbed angular correlation spectroscopy. Experiments with cultured Kupffer cells in monolayer also revealed that incorporation of cholesterol results in a decrease of the uptake and an increase of the intracellular stability of cholesteryl [14C]oleate-labeled liposomes. Finally, incubation of both types of liposomes with lysosomal fractions prepared from rat liver demonstrated a difference in susceptibility to lysosomal degradation: the cholesterol-free vesicles were much more sensitive to lysosomal esterase than the cholesterol-containing liposomes. These results may be relevant to the application of liposomes as a drug carrier system to liver and spleen (macrophages).