Structure of a heteropolymeric type 4 pilus from a monoderm bacterium.

Type 4 pili (T4P) are important virulence factors, which belong to a superfamily of nanomachines ubiquitous in prokaryotes, called type 4 filaments (T4F). T4F are defined as helical polymers of type 4 pilins. Recent advances in cryo-electron microscopy (cryo-EM) led to structures of several T4F, revealing that the long N-terminal α-helix (α1) - the trademark of pilins - packs in the centre of the filaments to form a hydrophobic core. In diderm bacteria - all available bacterial T4F structures are from diderm species - a portion of α1 is melted (unfolded). Here we report that this architecture is conserved in phylogenetically distant monoderm species by determining the structure of Streptococcus sanguinis T4P. Our 3.7 Å resolution cryo-EM structure of S. sanguinis heteropolymeric T4P and the resulting full atomic model including all minor pilins highlight universal features of bacterial T4F and have widespread implications in understanding T4F biology.

Effectiveness of an interactive web-based health program for adults: a study protocol for three concurrent controlled-randomized trials (EVA-TK-Coach).

BACKGROUND: A healthy lifestyle can help prevent diseases that impair quality of life and lead to premature death. The Techniker health insurance fund offers a comprehensive online health program to support users in achieving their health goals of Increasing Fitness, Losing and Maintaining Weight, or Smoking Cessation. METHODS: The aim of this study is to test the long-term effectiveness of the web-based TK-HealthCoach with regard to the primary outcomes of increased physical activity, sustainable weight reduction, and smoking abstinence. We are conducting three interconnected, randomized controlled trials (RCT), one for each health goal, within which participants are allocated to an intervention group (interactive online health program) or a control group (non-interactive online health program). The effects of the intervention groups compared to the control groups will be analyzed by multi-level models for change. Participants' data are captured via online questionnaires before the program starts (baseline t0), again when it ends (t1), and later at two follow-up surveys (t2 and t3); the latter 12 months after t1. We are documenting socio-demographic, health-related, and psychological variables as well as usage behavior data of the programs. According to our sample size calculation, we have to enroll 1114 participants in each Losing and Maintaining Weight and Increasing Fitness RCT and 339 participants in the Smoking Cessation RCT. Additionally, 15-20 participants in the interactive smoking-cessation program will be invited to qualitative telephone interviews with the aim to obtain detailed information concerning utilization, compliance, and satisfaction. The online RCTs' inclusion criteria are: adults of each gender regardless of whether they are insured with Techniker health insurance fund. Persons with impairments or pre-existing conditions require a medical assessment as to whether the program is suitable for them. Specific exclusion criteria apply to each program/RCT. DISCUSSION: We assume that study participants will improve their health behavior by using the offered online health programs and that each health goal's intervention group will reveal advantages regarding the outcome variables compared to the control groups. Study enrollment started on January 1, 2020. TRIAL REGISTRATION: German Clinical Trials Register, Universal Trial Number (UTN): U1111-1245-0273 . Registered on 11 December 2019.

The mycoplasma surface proteins MIB and MIP promote the dissociation of the antibody-antigen interaction.

Mycoplasma immunoglobulin binding (MIB) and mycoplasma immunoglobulin protease (MIP) are surface proteins found in the majority of mycoplasma species, acting sequentially to capture antibodies and cleave off their VH domains. Cryo-electron microscopy structures show how MIB and MIP bind to a Fab fragment in a "hug of death" mechanism. As a result, the orientation of the VL and VH domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability to promote the dissociation of the antibody-antigen complex. This system is functional in cells and protects mycoplasmas from antibody-mediated agglutination. These results highlight the key role of the MIB-MIP system in immunity evasion by mycoplasmas through an unprecedented mechanism, and open exciting perspectives to use these proteins as potential tools in the antibody field.

Evaluation of a Mobile Phone App for Patients With Pollen-Related Allergic Rhinitis: Prospective Longitudinal Field Study.

BACKGROUND: Mobile health apps have great potential to support the self-management of chronic conditions such as allergic diseases, which constitute significant challenges in health care. However, the health app market is confusing for users, as it is vast, dynamic, and lacks scientific evidence regarding the effectiveness of the apps on offer. To our knowledge, no health app for pollen-related allergic rhinitis has been evaluated. OBJECTIVE: The aim of our study was to evaluate the Husteblume mobile phone health app, developed in Germany to facilitate the self-management of pollen-related allergic rhinitis. METHODS: We evaluated usability and changes in quality of life, health literacy, and self-efficacy for managing one's chronic disease. We conducted 2 online surveys of registered users of the app, 1 before and 1 after the 2017 pollen season, allowing for the analysis of both cross-sectional and longitudinal data in a field setting. RESULTS: The sample comprised 661 app users at the first measurement point and 143 users at follow-up. The subgroup of study participants at follow-up rated the usability of the app as good or very good. There were no significant changes in patient-reported outcomes such as quality of life, health literacy, and self-efficacy between the 2 measurement points (P>.05). However, those reached at follow-up perceived subjective improvements due to the app: 55.9% (80/143) reported being subjectively better informed about their allergy, 27.3% (39/143) noted improved quality of life, 33.6% (48/143) reported subjectively better coping with their allergy, and 28.0% (40/143) felt better prepared for the consultation with their physician. Finally, 90.9% (130/143) users did not identify any adverse effects of the app. CONCLUSIONS: Despite some methodological caveats, the results of the evaluation of the Husteblume app are encouraging for the subgroup using the app in the long term. However, further studies evaluating the effectiveness of the app are needed. TRIAL REGISTRATION: German Clinical Trials Register DRKS00011897; https://tinyurl.com/yxxrg9av.

Validation of a German version of the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E).

INTRODUCTION: Goal of the present study was the validation of a German version of the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E). METHODS: 197 adult epilepsy patients completed the NDDI-E (185 completed both the NDDI-E and BDI). 95 patients received psychiatric consults. RESULTS: 33 patients received a diagnosis of major depression according to ICD-10 criteria. Internal consistency of the NDDI-E was .83. Receiver operating characteristics (ROC) showed an area under the curve of 0.92. Applying a cutoff score of ≥14 resulted in both sensitivity and specificity of 0.85. In the subsample with psychiatric consult, at the same optimal cutoff, sensitivity was 0.92, and specificity was 0.86. Further analyses showed a high concurrent validity with the BDI. DISCUSSION: The German version of the NDDI-E constitutes a brief and reliable depression screening instrument for epilepsy patients.