[Video-Assisted Psychotherapy For Refugees: A Pilot Study]. / Videogestützte Psychotherapie für Geflüchtete: Eine Pilotstudie.

OBJECTIVE: Global conflicts and humanitarian crises led to an increase in forced migration to Germany in recent years. To improve the mental health care system for refugees and asylum seekers in Germany perspectively, we aim to examine the feasibility of implementing the culturally sensitive group psychotherapy Empowerment for refugees with affective disorders in a video-assisted setting. METHODS: Empowerment is a culturally sensitive, interpreter-assisted intervention for the treatment of depressive and stress-related symptoms in refugees. Four male refugees from Afghanistan participated in a pilot study. The intervention included 16 modules delivered via video over a 12-week period. RESULTS: The internet connection was frequently unstable and led to organizational challenges. The therapy was feasible in terms of linguistic and interactional aspects. DISCUSSION: The stability of the internet connection represents the major criterion for a successful implementation of the therapy. Implications for future studies are discussed. CONCLUSION: Regarding the potential opportunities to improve the mental health care provision to refugees and asylum seekers in the future, the video-assisted therapy concept could be investigated in a randomized controlled trial.

Empowerment group therapy for refugees with affective disorders: results of a multicenter randomized controlled trial.

BACKGROUND: Against the background of missing culturally sensitive mental health care services for refugees, we developed a group intervention (Empowerment) for refugees at level 3 within the stratified Stepped and Collaborative Care Model of the project Mental Health in Refugees and Asylum Seekers (MEHIRA). We aim to evaluate the effectiveness of the Empowerment group intervention with its focus on psychoeducation, stress management, and emotion regulation strategies in a culturally sensitive context for refugees with affective disorders compared to treatment-as-usual (TAU). METHOD: At level 3 of the MEHIRA project, 149 refugees and asylum seekers with clinically relevant depressive symptoms were randomized to the Empowerment group intervention or TAU. Treatment comprised 16 therapy sessions conducted over 12 weeks. Effects were measured with the Patient Health Questionnaire-9 (PHQ-9) and the Montgomery-Åsberg Depression Rating Scale (MÅDRS). Further scales included assessed emotional distress, self-efficacy, resilience, and quality of life. RESULTS: Intention-to-treat analyses show significant cross-level interactions on both self-rated depressive symptoms (PHQ-9; F(1,147) = 13.32, p < 0.001) and clinician-rated depressive symptoms (MÅDRS; F(1,147) = 6.91, p = 0.01), indicating an improvement in depressive symptoms from baseline to post-intervention in the treatment group compared to the control group. The effect sizes for both scales were moderate (d = 0.68, 95% CI 0.21-1.15 for PHQ-9 and d = 0.51, 95% CI 0.04-0.99 for MÅDRS). CONCLUSION: In the MEHIRA project comparing an SCCM approach versus TAU, the Empowerment group intervention at level 3 showed effectiveness for refugees with moderately severe depressive symptoms.

Predicting treatment outcomes of the Empowerment group intervention for refugees with affective disorders: Findings from the MEHIRA project.

BACKGROUND: Research on outcome predictors in the field of transcultural treatment for refugees and asylum seekers (RAS) is scarce. We aimed to evaluate predictors of outcome of a group intervention (Empowerment) for RAS with affective disorders which was incorporated at level three of the stratified stepped-care model within the Mental Health in Refugees and Asylum Seekers (MEHIRA) project. METHODS: A predictor analysis was performed at level three of the MEHIRA project, where 149 refugees with moderate depressive symptoms were treated either with Empowerment or Treatment-as-usual (TAU). Outcome measures were depression severity as assessed by patient-rated Patient Health Questionnaire 9 (PHQ-9) and clinician-rated Montgomery Asberg Depression Rating Scale (MADRS). Regression models with change scores (T1-T0) of PHQ-9 and MADRS as dependent variables were fit. Predictor selection was a mixed-method approach combining testing of literature-based hypotheses and explorative hypothesis-generating analyses of multiple baseline variables. RESULTS: Intention-to-treat (ITT) analyses revealed significant linear relationships between change in PHQ-9 and baseline depression severity (ß = -0.35, t = -3.27, p = .002) and perceived self-efficacy (ß = -0.24, t = -2.26, p = .027) in the treatment (verum) condition. MADRS change scores were predicted by baseline depression severity (ß = -0.71, t = -8.65, p < .001) in the treatment (verum) condition. LIMITATIONS: Due to small cell numbers, single predictors could not be evaluated reliably. CONCLUSIONS: Severity of depression and self-efficacy at baseline were predictors of symptom improvement at level three (Empowerment) of the MEHIRA project. Comorbidity and trauma indicators did not predict outcomes in the treatment (verum) condition, pointing towards broad applicability of the Empowerment intervention in refugee populations.

Clinical Importance of a Peritoneal Interposition Flap to Prevent Symptomatic Lymphoceles after Robot-Assisted Radical Prostatectomy and Pelvic Lymph Node Dissection: A Systematic Review and Meta-Analysis.

BACKGROUND: Robot-assisted radical prostatectomy (RARP) including pelvic lymph node dissection (PLND) is the current state of the art in surgical therapy of localized prostate cancer with intermediate or high risk. PLND in particular is associated with morbidity inherent to this method; the rate of symptomatic lymphoceles (sLCs), for example, ranges up to 10%. OBJECTIVE: Various intraoperative modifications have been developed with the aim of reducing the sLC rate. Based on current studies, a peritoneal interposition flap (PIF) appears to be one of the most effective methods for this purpose. Under the criteria of a systematic review, 5 retrospective studies have been identified until now, 4 of which showed a positive effect of PIF on the sLC rate. RESULTS AND LIMITATIONS: A total of 1,308 patients were included in the aggregated analysis of these 5 studies. The amount of sLCs was 1.3% (8/604) and 5.7% (40/704) in the PIF and standard groups, respectively (p < 0.001). The resulting odds ratio (OR) was 0.23 (95% confidence interval [CI]: 0.05-0.99), taking in-to account a noteworthy heterogeneity of the 5 studies (Q = 9.47, p = 0.05; I2 = 58%). In addition, a prospective randomized and blinded study (Pianoforte trial) with corresponding sLC rates of 8.3% (9/108) versus 9.7% (12/124) (p = 0.820) exists. In this study, the OR was 0.85 (95% CI: 0.34-2.10, p = 0.722). CONCLUSION: Despite positive results from retrospective studies with indirect evidence, the role of the PIF in the reduction of sLC in RARP could not be conclusively assessed yet. The results of the first prospective randomized study do not show a positive effect of PIF, declaring a research gap for further studies with direct evidence.

A Central Clearing Clinic to Provide Mental Health Services for Refugees in Germany.

Objective: To determine migration related distress pattern in refugees and feasibility of a de novo established, central low-threshold outpatient clinic serving more than 80,000 newly arrived refugees in the metropole of Berlin. Methods: In an observational cohort study the relative prevalence of major psychiatric disorders by age, place of living within berlin, language and region of origin were assessed in a refugee cohort from 63 nationalities speaking 36 languages. Findings: Within 18 months, a total of 3,096 cases with a mean age of 29.7 years (11.7) have been referred from all 12 districts and 165 of 182 subdistricts of Berlin to the CCC. 33.7% of the patients were female. The three most frequent diagnoses were unipolar depression (40.4%), posttraumatic stress disorder (24.3%), and adjustment disorder (19.6%). Conclusion: The present data gives insight into the distribution of mental disorders in a large sample of refugees and provides evidence that a CCC is an effective service to quickly and broadly provide psychiatric consultations and thus to overcome classical barriers refugees usually experience in the host communities. In Berlin, Germany, and Europe treatment resources for this population should focus on stress and trauma related disorders.

EAU-ESMO Consensus Statements on the Management of Advanced and Variant Bladder Cancer-An International Collaborative Multistakeholder Effort†: Under the Auspices of the EAU-ESMO Guidelines Committees.

BACKGROUND: Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial. OBJECTIVE: To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management. DESIGN: A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts prior to voting during a consensus conference. SETTING: Online Delphi survey and consensus conference. PARTICIPANTS: The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), and 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus). RESULTS AND LIMITATIONS: Overall, 116 statements were included in the Delphi survey. Of these statements, 33 (28%) achieved level 1 consensus and 49 (42%) achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease, and the evolving role of checkpoint inhibitor therapy in metastatic disease. CONCLUSIONS: These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time when further evidence is available to guide our approach. PATIENT SUMMARY: This report summarises findings from an international, multistakeholder project organised by the EAU and ESMO. In this project, a steering committee identified areas of bladder cancer management where there is currently no good-quality evidence to guide treatment decisions. From this, they developed a series of proposed statements, 71 of which achieved consensus by a large group of experts in the field of bladder cancer. It is anticipated that these statements will provide further guidance to health care professionals and could help improve patient outcomes until a time when good-quality evidence is available.

Long-term survival and complications following bladder-preserving brachytherapy in patients with cT1-T2 bladder cancer.

BACKGROUND AND PURPOSE: Radical cystectomy (RC) is considered standard treatment for muscle-invasive bladder cancer (BC) and high-risk non-muscle invasive BC. In selected cases, bladder-sparing treatment using brachytherapy can be offered. We examined the outcome after brachytherapy in comparison to RC in terms of survival, complications and bladder preservation in patients with cT1G3-T2N0M0 BC. MATERIALS AND METHODS: Between 1988 and 2016, 301 patients underwent brachytherapy in two centres. Overall survival (OS) and disease specific survival (DSS) after brachytherapy and RC were assessed using Kaplan-Meier curves. Cox proportional hazards modelling was used to determine variables associated with OS and DSS. Local recurrences, bladder preservation and salvage cystectomy (SC) after brachytherapy were reported. Complications after brachytherapy, RC and SC were compared using CTCAE criteria. RESULTS: Median follow-up was 9.6 years (95% confidence interval (CI): 8.8-10.4) after brachytherapy and 10.6 years (95% CI: 10.0-11.2) after RC. Five/10-year OS was 66%/49% after brachytherapy and 68%/53% after RC (p = 0.4). Five/10-year DSS was 73%/67% after brachytherapy and 75%/65% after RC (p = 0.8). Intravesical recurrence occurred in 58/259 brachytherapy patients after which salvage cystectomy was performed in 32 patients. In total, 84% of brachytherapy-treated patients preserved their bladder. The brachytherapy cohort experienced less high grade complications than the RC cohort (p = 0.02). CONCLUSION: In selected patients with solitary, ≤5 cm cT1G3-T2N0M0 bladder tumours brachytherapy is a bladder-sparing therapy with good survival outcome and with a favourable complication rate compared to RC.

Prognostic Performance and Reproducibility of the 1973 and 2004/2016 World Health Organization Grading Classification Systems in Non-muscle-invasive Bladder Cancer: A European Association of Urology Non-muscle Invasive Bladder Cancer Guidelines Panel Systematic Review.

CONTEXT: Tumour grade is an important prognostic indicator in non-muscle-invasive bladder cancer (NMIBC). Histopathological classifications are limited by interobserver variability (reproducibility), which may have prognostic implications. European Association of Urology NMIBC guidelines suggest concurrent use of both 1973 and 2004/2016 World Health Organization (WHO) classifications. OBJECTIVE: To compare the prognostic performance and reproducibility of the 1973 and 2004/2016 WHO grading systems for NMIBC. EVIDENCE ACQUISITION: A systematic literature search was undertaken incorporating Medline, Embase, and the Cochrane Library. Studies were critically appraised for risk of bias (QUIPS). For prognosis, the primary outcome was progression to muscle-invasive or metastatic disease. Secondary outcomes were disease recurrence, and overall and cancer-specific survival. For reproducibility, the primary outcome was interobserver variability between pathologists. Secondary outcome was intraobserver variability (repeatability) by the same pathologist. EVIDENCE SYNTHESIS: Of 3593 articles identified, 20 were included in the prognostic review; three were eligible for the reproducibility review. Increasing tumour grade in both classifications was associated with higher disease progression and recurrence rates. Progression rates in grade 1 patients were similar to those in low-grade patients; progression rates in grade 3 patients were higher than those in high-grade patients. Survival data were limited. Reproducibility of the 2004/2016 system was marginally better than that of the 1973 system. Two studies on repeatability showed conflicting results. Most studies had a moderate to high risk of bias. CONCLUSIONS: Current grading classifications in NMIBC are suboptimal. The 1973 system identifies more aggressive tumours. Intra- and interobserver variability was slightly less in the 2004/2016 classification. We could not confirm that the 2004/2016 classification outperforms the 1973 classification in prediction of recurrence and progression. PATIENT SUMMARY: This article summarises the utility of two different grading systems for non-muscle-invasive bladder cancer. Both systems predict progression and recurrence, although pathologists vary in their reporting; suggestions for further improvements are made.

Prefrontal transcranial direct current stimulation (tDCS) as treatment for major depression: study design and methodology of a multicenter triple blind randomized placebo controlled trial (DepressionDC).

Transcranial direct current stimulation (tDCS) has been proposed as novel treatment for major depressive disorder (MDD) based on clinical pilot studies as well as randomized controlled monocentric trials. The DepressionDC trial is a triple-blind (blinding of rater, operator and patient), randomized, placebo controlled multicenter trial investigating the efficacy and safety of prefrontal tDCS used as additive treatment in MDD patients who have not responded to selective serotonin reuptake inhibitors (SSRI). At 5 study sites, 152 patients with MDD receive a 6-weeks treatment with active tDCS (anode F3 and cathode F4, 2 mA intensity, 30 min/day) or sham tDCS add-on to a stable antidepressant medication with an SSRI. Follow-up visits are at 3 and 6 months after the last tDCS session. The primary outcome measure is the change of the Montgomery-Asberg Depression Rating Scale (MADRS) scores at week 6 post-randomisation compared to baseline. Secondary endpoints also cover other psychopathological domains, and a comprehensive safety assessment includes measures of cognition. Patients undergo optional investigations comprising genetic testing and functional magnetic resonance imaging (fMRI) of structural and functional connectivity. The study uses also an advanced tDCS technology including standard electrode positioning and recording of technical parameters (current, impedance, voltage) in every tDCS session. Aside reporting the study protocol here, we present a novel approach for monitoring technical parameters of tDCS which will allow quality control of stimulation and further analysis of the interaction between technical parameters and clinical outcome. The DepressionDC trial will hopefully answer the important clinical question whether prefrontal tDCS is a safe and effective antidepressant intervention in patients who have not sufficiently responded to SSRIs. TRIAL REGISTRY: ClinicalTrials.gov Identifier NCT0253016.

No Effect of Cathodal Transcranial Direct Current Stimulation on Fear Memory in Healthy Human Subjects.

BACKGROUND: Studies have demonstrated that fear memories can be modified using non-invasive methods. Recently, we demonstrated that anodal transcranial direct current stimulation (tDCS) of the right dorsolateral prefrontal cortex is capable of enhancing fear memories. Here, we examined the effects of cathodal tDCS of the right dorsolateral prefrontal cortex during fear reconsolidation in humans. METHODS: Seventeen young, healthy subjects were randomly assigned to two groups, which underwent fear conditioning with mild electric stimuli paired with a visual stimulus. Twenty-four hours later, both groups were shown a reminder of the conditioned fearful stimulus. Shortly thereafter, they received either tDCS (right prefrontal-cathodal, left supraorbital-anodal) for 20 min at 1 mA, or sham stimulation. A day later, fear responses of both groups were compared. RESULTS: On Day 3, during fear response assessment, there were no significant differences between the tDCS and sham group (p > 0.05). CONCLUSION: We conclude that cathodal tDCS of the right dorsolateral prefrontal cortex (right prefrontal-cathodal, left supraorbital-anodal) did not influence fear memories.

Tourette syndrome is associated with insecure attachment and higher aggression.

This study explored the degree to which adult patients with Tourette syndrome (TS) exhibit particular attachment styles and the possible association between the underlying attachment dimensions and forms of aggression. Fifty-three TS patients (ages 17-72 years) and 54 matched healthy controls completed the Experiences in Close Relationships-Revised Scale (ECR-R) and the Aggression Questionnaire (AQ). The data were analysed with ANOVA F-tests, t-tests, and Pearson's correlation coefficient. TS patients showed significantly higher scores in relationship anxiety ( p < 0.001) and relationship avoidance ( p = 0.001) in the ECR-R and significantly higher aggression scores in the AQ ( p < 0.001). The total AQ score correlated significantly with the ECR-R dimension anxiety ( p < 0.001). These are the first findings on TS patients' attachment styles and anger symptoms. It remains unclear whether attachment anxiety and avoidance are risk factors for TS or whether the disorder itself induces attachment disorders. Prospective studies with detailed attachment interviews would help to explore this issue.

Association of tissue mRNA and serum antigen levels of members of the urokinase-type plasminogen activator system with clinical and prognostic parameters in prostate cancer.

The objective was to determine the mRNA expression and protein levels of uPA system components in tissue specimens and serum samples, respectively, from prostate cancer (PCa) patients and to assess their association with clinicopathological parameters and overall survival (OS). The mRNA expression levels of uPA, its receptor (uPAR), and its inhibitor type 1 (PAI-1) were analyzed in corresponding malignant and adjacent nonmalignant tissue specimens from 132 PCa patients by quantitative PCR. Preoperative serum samples from 81 PCa patients were analyzed for antigen levels of uPA system members by ELISA. RNA levels of uPA system components displayed significant correlations with each other in the tumor tissues. A significantly decreased uPA mRNA expression in PCa compared to the corresponding nonmalignant tissue was detected. High uPA mRNA level was significantly associated with a high Gleason score. Elevated concentration of soluble uPAR (suPAR) in serum was significantly associated with a poor OS of PCa patients (P = 0.022). PCa patients with high suPAR levels have a significantly higher risk of death (multivariate Cox's regression analysis; HR = 7.12, P = 0.027). The association of high suPAR levels with poor survival of PCa patients suggests a prognostic impact of suPAR levels in serum of cancer patients.

Emotional and cognitive empathy in first-year medical students.

Objectives. Doctors' empathy towards their patients is considered important for treatment outcome. However, during medical school there might be a decline in empathy called "hardening of the heart." This study evaluated the cognitive and emotional empathy in medical students and investigated the influence of a preference for a specialty and students attachment styles. Methods. 126 first-year medical students were included and completed the Reading the Mind in the Eyes Test revised version (RME-R), the Balanced Emotional Empathy Scale (BEES), and the Experiences in Close Relationships-Revised Adult Attachment Questionnaire (ECR-R). Results. Students identified 22 ± 4.30 of 36 photographs in the RME-R test correctly (norm: 26). The female students' mean BEES total score was 51.1 ± 17.1 and the male students' 27.2 ± 22.6; P < 0.0001. The female students' mean BEES score was significantly (P = 0.0037) below the female norm of 60. Students who preferred a specialty with continuity of patient care scored significantly higher in the BEES (P = 0.014). A more avoidant attachment style was associated with a lower BEES score (P = 0.021). Conclusion. The students showed low emotional and cognitive empathy scores and an avoidant attachment style. This supports the inclusion of specific training in cognitive and emotional empathy in medical education.

European guidelines on upper tract urothelial carcinomas: 2013 update.

CONTEXT: The European Association of Urology (EAU) guideline group for upper tract urothelial carcinoma (UTUC) has prepared updated guidelines to aid clinicians in assessing the current evidence-based management of UTUC and to incorporate present recommendations into daily clinical practice. OBJECTIVE: To provide a brief overview of the EAU guidelines on UTUC as an aid to clinicians in their daily clinical practice. EVIDENCE ACQUISITION: The recommendations provided in the current guidelines are based on a thorough review of available UTUC guidelines and articles identified using a systematic search of Medline. Data on urothelial malignancies and UTUCs in the literature were searched using Medline with the following keywords: urinary tract cancer; urothelial carcinomas; upper urinary tract, carcinoma; renal pelvis; ureter; bladder cancer; chemotherapy; nephroureterectomy; adjuvant treatment; instillation; neoadjuvant treatment; recurrence; risk factors; nomogram; and survival. References were weighted by a panel of experts. EVIDENCE SYNTHESIS: There is a lack of data in the current literature to provide strong recommendations (ie, grade A) due to the rarity of the disease. A number of recent multicentre studies are now available, and there is a growing interest in UTUC in the recent literature. Overall, 135 references have been included here, but most of these studies are still retrospective analyses. The TNM 2009 classification is recommended. Recommendations are given for diagnosis as well as radical and conservative treatment (ie, imperative and elective cases); additionally, prognostic factors are discussed. Recommendations are also provided for patient follow-up after different therapeutic options. CONCLUSIONS: These guidelines contain information for the management of individual patients according to a current standardised approach. Physicians must take into account the specific clinical characteristics of each individual patient when determining the optimal treatment regimen including tumour location, grade, and stage; renal function; molecular marker status; and medical comorbidities.

Self-recognition and Ca2+-dependent carbohydrate-carbohydrate cell adhesion provide clues to the cambrian explosion.

The Cambrian explosion of life was a relatively short period approximately 540 Ma that marked a generalized acceleration in the evolution of most animal phyla, but the trigger of this key biological event remains elusive. Sponges are the oldest extant Precambrian metazoan phylum and thus a valid model to study factors that could have unleashed the rise of multicellular animals. One such factor is the advent of self-/non-self-recognition systems, which would be evolutionarily beneficial to organisms to prevent germ-cell parasitism or the introduction of deleterious mutations resulting from fusion with genetically different individuals. However, the molecules responsible for allorecognition probably evolved gradually before the Cambrian period, and some other (external) factor remains to be identified as the missing triggering event. Sponge cells associate through calcium-dependent, multivalent carbohydrate-carbohydrate interactions of the g200 glycan found on extracellular proteoglycans. Single molecule force spectroscopy analysis of g200-g200 binding indicates that calcium affects the lifetime (+Ca/-Ca: 680 s/3 s) and bond reaction length (+Ca/-Ca: 3.47 A/2.27 A). Calculation of mean g200 dissociation times in low and high calcium within the theoretical framework of a cooperative binding model indicates the nonlinear and divergent characteristics leading to either disaggregated cells or stable multicellular assemblies, respectively. This fundamental phenomenon can explain a switch from weak to strong adhesion between primitive metazoan cells caused by the well-documented rise in ocean calcium levels at the end of Precambrian time. We propose that stronger cell adhesion allowed the integrity of genetically uniform animals composed only of "self" cells, facilitating genetic constitutions to remain within the metazoan individual and be passed down inheritance lines. The Cambrian explosion might have been triggered by the coincidence in time of primitive animals endowed with self-/non-self-recognition and of a surge in seawater calcium that increased the binding forces between their calcium-dependent cell adhesion molecules.

Cyclosporin A suspends transplantation reactions in the marine sponge Microciona prolifera.

Sponges are the simplest extant animals but nevertheless possess self-nonself recognition that rivals the specificity of the vertebrate MHC. We have used dissociated cell assays and grafting techniques to study tissue acceptance and rejection in the marine sponge Microciona prolifera. Our data show that allogeneic, but not isogeneic, cell contacts trigger cell death and an increased expression of cell adhesion and apoptosis markers in cells that accumulate in graft interfaces. Experiments investigating the possible existence of immune memory in sponges indicate that faster second set reactions are nonspecific. Among the different cellular types, gray cells have been proposed to be the sponge immunocytes. Fluorescence confocal microscopy results from intact live grafts show the migration of autofluorescent gray cells toward graft contact zones and the inhibition of gray cell movements in the presence of nontoxic concentrations of cyclosporin A. These results suggest that cell motility is an important factor involved in sponge self/nonself recognition. Communication between gray cells in grafted tissues does not require cell contact and is carried by an extracellular diffusible marker. The finding that a commonly used immunosuppressor in human transplantation such as cyclosporin A blocks tissue rejection in marine sponges indicates that the cellular mechanisms for regulating this process in vertebrates might have appeared at the very start of metazoan evolution.

Proteoglycan mechanics studied by single-molecule force spectroscopy of allotypic cell adhesion glycans.

Early Metazoans had to evolve the first cell adhesion system addressed to maintaining stable interactions between cells constituting different individuals. As the oldest extant multicellular animals, sponges are good candidates to have remnants of the molecules responsible for that crucial innovation. Sponge cells associate in a species-specific process through multivalent calcium-dependent interactions of carbohydrate structures on an extracellular membrane-bound proteoglycan termed aggregation factor. Single-molecule force spectroscopy studies of the mechanics of aggregation factor self-binding indicate the existence of intermolecular carbohydrate adhesion domains. A 200-kDa aggregation factor glycan (g200) involved in cell adhesion exhibits interindividual differences in size and epitope content which suggest the existence of allelic variants. We have purified two of these g200 distinct forms from two individuals of the same sponge species. Comparison of allotypic versus isotypic g200 binding forces reveals significant differences. Surface plasmon resonance measurements show that g200 self-adhesion is much stronger than its binding to other unrelated glycans such as chondroitin sulfate. This adhesive specificity through multiple carbohydrate binding domains is a type of cooperative interaction that can contribute to explain some functions of modular proteoglycans in general. From our results it can be deduced that the binding strength/surface area between two aggregation factor molecules is comparable with that of focal contacts in vertebrate cells, indicating that strong carbohydrate-based cell adhesions evolved at the very start of Metazoan history.

Carbohydrate-carbohydrate interaction as a major force initiating cell-cell recognition.

Sponges were the earliest multicellular organisms to evolve through the development of cell recognition and adhesion processes mediated by cell surface proteoglycans. Information on sponges has an extra added value because, as a group, they are the oldest Metazoans alive and contribute more to our understanding of life on earth than knowledge of other animal groups. Although the proteoglycans are emerging as key players in various physiological and pathophysiological cellular events, little is known about the carbohydrate moiety of the proteoglycan molecule. Until recently there was no evidence provided for the existence of specific and biologically significant carbohydrate-carbohydrate interaction. We show here that the interaction between single oligosaccharides of surface proteoglycans is relatively strong (in the 200-300 piconewtons range) and in the same range as other relevant biological interactions, like those between antibodies and antigens. This carbohydrate-carbohydrate recognition is highly species-specific and perfectly mimics specific cell-cell recognition. Both the strength and the species-specificity of the carbohydrate-carbohydrate interaction are guaranteed by polyvalency, by compositional and architectural differences between carbohydrates, and by the arrangement of the carbohydrate chain in a three-dimensional context. Ca(2+)-ions are essential and probably provide coordinating forces. Our findings confirm the existence and character of species-specific carbohydrate-carbohydrate recognition fundamental to cell recognition and adhesion events.