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Dive into the research topics where Kai Kronfeld is active.

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Featured researches published by Kai Kronfeld.


Lancet Neurology | 2006

Efficacy of acupuncture for the prophylaxis of migraine: a multicentre randomised controlled clinical trial

Hans-Christoph Diener; Kai Kronfeld; Gabriele Boewing; Margitta Lungenhausen; Christoph Maier; Albrecht Molsberger; Martin Tegenthoff; Hans-Joachim Trampisch; M. Zenz; Rolf Meinert

BACKGROUND Our aim was to assess the efficacy of a part-standardised verum acupuncture procedure, in accordance with the rules of traditional Chinese medicine, compared with that of part-standardised sham acupuncture and standard migraine prophylaxis with beta blockers, calcium-channel blockers, or antiepileptic drugs in the reduction of migraine days 26 weeks after the start of treatment. METHODS This study was a prospective, randomised, multicentre, double-blind, parallel-group, controlled, clinical trial, undertaken between April 2002 and July 2005. Patients who had two to six migraine attacks per month were randomly assigned verum acupuncture (n=313), sham acupuncture (n=339), or standard therapy (n=308). Patients received ten sessions of acupuncture treatment in 6 weeks or continuous prophylaxis with drugs. Primary outcome was the difference in migraine days between 4 weeks before randomisation and weeks 23-26 after randomisation. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN52683557. FINDINGS Of 1295 patients screened, 960 were randomly assigned to a treatment group. Immediately after randomisation, 125 patients (106 from the standard group) withdrew their consent to study participation. 794 patients were analysed in the intention-to-treat popoulation and 443 in the per-protocol population. The primary outcome showed a mean reduction of 2 .3 days (95% CI 1.9-2.7) in the verum acupuncture group, 1.5 days (1.1-2.0) in the sham acupuncture group, and 2.1 days (1.5-2.7) in the standard therapy group. These differences were statistically significant compared with baseline (p<0.0001), but not across the treatment groups (p=0.09). The proportion of responders, defined as patients with a reduction of migraine days by at least 50%, 26 weeks after randomisation, was 47% in the verum group, 39% in the sham acupuncture group, and 40% in the standard group (p=0.133). INTERPRETATION Treatment outcomes for migraine do not differ between patients treated with sham acupuncture, verum acupuncture, or standard therapy.


Lancet Neurology | 2012

Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial.

Silke Walter; Panagiotis Kostopoulos; Anton Haass; Isabel Keller; Martin Lesmeister; Thomas Schlechtriemen; Christian L. Roth; P. Papanagiotou; Iris Q. Grunwald; Helmut Schumacher; Stephan Helwig; Julio Viera; Heiko Körner; Maria Alexandrou; Umut Yilmaz; Karin Ziegler; Kathrin Schmidt; Rainer Dabew; Darius Kubulus; Yang Liu; Thomas Volk; Kai Kronfeld; Christian Ruckes; Thomas Bertsch; W. Reith; Klaus Fassbender

BACKGROUND Only 2-5% of patients who have a stroke receive thrombolytic treatment, mainly because of delay in reaching the hospital. We aimed to assess the efficacy of a new approach of diagnosis and treatment starting at the emergency site, rather than after hospital arrival, in reducing delay in stroke therapy. METHODS We did a randomised single-centre controlled trial to compare the time from alarm (emergency call) to therapy decision between mobile stroke unit (MSU) and hospital intervention. For inclusion in our study patients needed to be aged 18-80 years and have one or more stroke symptoms that started within the previous 2·5 h. In accordance with our week-wise randomisation plan, patients received either prehospital stroke treatment in a specialised ambulance (equipped with a CT scanner, point-of-care laboratory, and telemedicine connection) or optimised conventional hospital-based stroke treatment (control group) with a 7 day follow-up. Allocation was not masked from patients and investigators. Our primary endpoint was time from alarm to therapy decision, which was analysed with the Mann-Whitney U test. Our secondary endpoints included times from alarm to end of CT and to end of laboratory analysis, number of patients receiving intravenous thrombolysis, time from alarm to intravenous thrombolysis, and neurological outcome. We also assessed safety endpoints. This study is registered with ClinicalTrials.gov, number NCT00153036. FINDINGS We stopped the trial after our planned interim analysis at 100 of 200 planned patients (53 in the prehospital stroke treatment group, 47 in the control group), because we had met our prespecified criteria for study termination. Prehospital stroke treatment reduced the median time from alarm to therapy decision substantially: 35 min (IQR 31-39) versus 76 min (63-94), p<0·0001; median difference 41 min (95% CI 36-48 min). We also detected similar gains regarding times from alarm to end of CT, and alarm to end of laboratory analysis, and to intravenous thrombolysis for eligible ischaemic stroke patients, although there was no substantial difference in number of patients who received intravenous thrombolysis or in neurological outcome. Safety endpoints seemed similar across the groups. INTERPRETATION For patients with suspected stroke, treatment by the MSU substantially reduced median time from alarm to therapy decision. The MSU strategy offers a potential solution to the medical problem of the arrival of most stroke patients at the hospital too late for treatment. FUNDING Ministry of Health of the Saarland, Germany, the Werner-Jackstädt Foundation, the Else-Kröner-Fresenius Foundation, and the Rettungsstiftung Saar.


American Journal of Psychiatry | 2013

Maintenance Cognitive-Behavioral Therapy and Manualized Psychoeducation in the Treatment of Recurrent Depression: A Multicenter Prospective Randomized Controlled Trial

Ulrich Stangier; Christine Hilling; Thomas Heidenreich; Anne Katrin Risch; Arnd Barocka; Ralf G.M. Schlösser; Kai Kronfeld; Christian Ruckes; Hartmut Berger; Joachim Röschke; Florian Weck; Stephan Volk; Martin Hambrecht; Richard Serfling; Ralf Erkwoh; Aglaja Stirn; Thomas Sobanski; Martin Hautzinger

OBJECTIVE This multicenter study compared the relapse and recurrence outcomes of two active treatments, maintenance cognitive-behavioral therapy (CBT) and manualized psychoeducation, both in addition to treatment as usual, in patients in remission from depression. METHOD This was a multicenter prospective randomized observer-blinded study with two parallel groups. The authors assessed 180 patients with three or more previous major depressive episodes who met remission criteria over a 2-month baseline period and who were randomly assigned to 16 sessions of either maintenance CBT or manualized psychoeducation over 8 months and then followed up for 12 months. The main outcome measure was time to first relapse or recurrence of a major depression, based on DSM-IV criteria, as assessed by blinded observers with the Longitudinal Interval Follow-Up Evaluation. RESULTS Cox regression analysis showed that time to relapse or recurrence of major depression did not differ significantly between treatment conditions, but a significant interaction was observed between treatment condition and number of previous episodes (<5 or ≥5). Within the subsample of patients with five or more previous episodes, maintenance CBT was significantly superior to manualized psychoeducation, whereas for patients with fewer than five previous episodes, no significant treatment differences were observed in time to relapse or recurrence. CONCLUSIONS The results indicate that maintenance CBT has significant effects on the prevention of relapse or recurrence only in patients with a high risk of depression recurrence. For patients with a moderate risk of recurrence, nonspecific effects and structured patient education may be equally effective.


Trends in Immunology | 2002

Tuning tumor-specific T-cell activation: a matter of costimulation?

Hinrich Abken; Andreas Hombach; Claudia Heuser; Kai Kronfeld; Barbara Seliger

Abstract The stimulation of a specific antitumor immune response, involving the recruitment of T cells and induction of T-cell effector functions, is an attractive possibility for cancer immunotherapy. In the past few years, advances in our understanding of the mechanisms of T-cell activation and costimulation have provided the basis for strategies to enhance antitumor immunity and break tolerance. These strategies include the equipment of tumor cells with costimulatory molecules such as B7, blockade of inhibitory signals on T cells (e.g. through cytotoxic T-lymphocyte antigen 4) and grafting of T cells with antigen-triggered, recombinant costimulatory receptors. Combining antigen-triggered activation with appropriate costimulatory pathways will lead to novel approaches to improve the efficacy of T-cell-mediated adoptive immunotherapy of malignant diseases.


Diabetes Care | 2015

Cognitive Behavioral Therapy Versus Sertraline in Patients With Depression and Poorly Controlled Diabetes: The Diabetes and Depression (DAD) Study: A Randomized Controlled Multicenter Trial.

Frank Petrak; Stephan Herpertz; Christian Albus; Norbert Hermanns; Christoph Hiemke; Wolfgang Hiller; Kai Kronfeld; Johannes Kruse; Bernd Kulzer; Christian Ruckes; Daniela Zahn; M. Müller

OBJECTIVE This study compared the long-term efficacy of a diabetes-specific cognitive behavioral group therapy (CBT) with sertraline in patients with diabetes and depression who initially responded to short-term depression treatment. RESEARCH DESIGN AND METHODS A randomized controlled single-blind trial was conducted in 70 secondary care centers across Germany comparing 12 weeks of CBT with sertraline in 251 patients with type 1 or 2 diabetes (mean HbA1c 9.3%, 78 mmol/mol) and major depression (Structured Clinical Interview for DSM-IV [SCID]). After 12 weeks, treatment responders (≥50% reduction Hamilton Depression Rating Scale [HAMD-17]) were included in the 1-year study phase where CBT patients were encouraged to use bibliotherapy and sertraline patients received continuous treatment. We analyzed differences for HbA1c (primary outcome) and reduction (HAMD-17) or remission (SCID) of depression from baseline to the 1-year follow-up using ANCOVA or logistic regression analysis. RESULTS After 12 weeks, 45.8% of patients responded to antidepressant treatment and were included in the 1-year study phase. Adjusted HbA1c mean score changes from baseline to the end of the long-term phase (−0.27, 95% CI −0.62 to 0.08) revealed no significant difference between interventions. Depression improved in both groups, with a significant advantage for sertraline (HAMD-17 change: −2.59, 95% CI 1.15–4.04, P < 0.05). CONCLUSIONS Depression improved under CBT and sertraline in patients with diabetes and depression, with a significant advantage for sertraline, but glycemic control remained unchanged. CBT and sertraline as single treatment are insufficient to treat secondary care diabetes patients with depression and poor glycemic control.


Thorax | 2013

Research in progress: put the orphanage out of business

Andrew Bush; Gisela Anthony; Angelo Barbato; Steve Cunningham; Annick Clement; Ralph Epaud; Carlee Gilbert; Lutz Goldbeck; Kai Kronfeld; Andrew G. Nicholson; Nicolaus Schwerk; Matthias Griese

Paediatric interstitial lung disease (ILD) is rare and diverse, meaning no single centre will see sufficient children to perform the studies needed to make progress. This EU FP-7 grant will standardise the evaluation of these rare conditions by establishing pan-European multidisciplinary expert panels and establish consensus on treatment protocols and standard operating procedures across Europe. We will work with patient groups to determine optimal treatment end-points and biomarkers. A biobank will be established as a Europe-wide resource for mechanistic studies. Ultimately we aim to do the first randomised controlled trial of a pharmacological treatment in paediatric ILD.


European Neuropsychopharmacology | 2016

Randomized controlled study of early medication change for non-improvers to antidepressant therapy in major depression - The EMC trial

André Tadić; Daniel Wachtlin; Mathias Berger; Dieter F. Braus; Dietrich van Calker; Norbert Dahmen; Nadine Dreimüller; Alice Engel; Stanislav Gorbulev; Isabella Helmreich; Anne-Katrin Kaiser; Kai Kronfeld; Konrad Friedrich Schlicht; Oliver Tüscher; Stefanie Wagner; Christoph Hiemke; Klaus Lieb

Patients with Major Depressive Disorder (MDD) and no improvement after two weeks of antidepressant pharmacotherapy have a high risk of treatment failure. The aim of the study was to determine whether an early medication change (EMC) strategy is superior to a guideline-based treatment in MDD patients without improvement after two weeks of antidepressant pharmacotherapy. Eight-hundred-and-eighty-nine patients with MDD were enrolled, 879 patients received the SSRI escitalopram. Of those, 192 patients had no improvement, defined as a reduction of < 20% on the Hamilton Depression Rating Scale (HAMD-17) after 14 days of treatment, and were randomly assigned to open treatment with the EMC strategy (n = 97; venlafaxine XR for study days 15-56; in case of sustained non-improvement on day 28, lithium augmentation for days 29-56) or TAU (n = 95; escitalopram continuation; non-responders on day 28 were switched to venlafaxine XR for four weeks, i.e. days 29-56). The primary outcome was remission (HAMD-17 ≤ 7) after 8 weeks of treatment as assessed by blinded raters. Remission rates were 24% for EMC and 16% for TAU, which was not significantly different (p = 0.2056). Sensitivity analyses for the primary and secondary effectiveness endpoints consistently showed favorable results for patients randomized to EMC. The results confirm data from post-hoc analyses of clinical trials showing that early non-improvement identifies patients who likely need alternate interventions. However, the herein used two-step switch/augmentation strategy for this risk group was not more effective than the control intervention. Alternate strategies and other design aspects are discussed in order to support researchers addressing the same research question.


International Journal of Cancer | 2005

B7-1 and B7-2 act differentially in the induction of a T cell response : Their impact for a HLA-matched and HLA-mismatched anti-tumor immunotherapy

Kai Kronfeld; Hinrich Abken; Barbara Seliger

The efficacy of T cell‐based immunotherapy is primarily due to efficient cellular activation that requires the engagement of 2 separate signals, i.e., via the T cell receptor complex and via co‐stimulatory molecules the prototype of which is CD28. In cellular activation, the CD28 ligands B7‐1 (CD80) and B7‐2 (CD86) are thought to play nearly identical roles in T cell activation. We monitored the T cell response upon co‐culture with HLA Class I‐matched and mismatched renal carcinoma cells, respectively, that express different levels of B7‐1 and B7‐2, respectively. In a HLA Class I‐mismatched co‐culture, T cell proliferation, IFN‐γ and GM‐CSF secretion equally depend on the levels of B7‐1 and B7‐2 on tumor cells. In contrast, in a HLA Class I‐matched situation, B7‐2 is more effective in the induction of IFN‐γ and GM‐CSF secretion than B7‐1, but both B7 molecules induce T cell proliferation equally efficient. B7‐2 is more effective than B7‐1 in inducing TNF‐α and IL‐10 secretion in both HLA Class I‐matched and mismatched situations. The distinct patterns of cytokine induction by B7‐1 and B7‐2 obviously depend on the HLA Class I compatibility. These conclusions have substantial implications for the development of B7‐based vaccines used for immunotherapies.


Pediatric Pulmonology | 2015

Hydroxychloroquine in children with interstitial (diffuse parenchymal) lung diseases.

Sarah Braun; Marion Ferner; Kai Kronfeld; Matthias Griese

Hydroxychloroquine (HCQ) is one of the drugs frequently used for the treatment of interstitial lung disease (ILD) in children (chILD). This use is off‐label and studies to analyze the effect and safety of HCQ in chILD are lacking. Therefore, a literature research on the usage of chloroquine (CQ) and HCQ in these conditions was done.


Molecular & Cellular Proteomics | 2005

B7/CD28 Costimulation of T Cells Induces a Distinct Proteome Pattern

Kai Kronfeld; Elisabeth O. Hochleitner; Simone Mendler; Jutta Goldschmidt; Rudolf Lichtenfels; Friedrich Lottspeich; Hinrich Abken; Barbara Seliger

Effective immune strategies for the eradication of human tumors require a detailed understanding of the interaction of tumor cells with the immune system, which might lead to an optimization of T cell responses. To understand the impact of B7-mediated costimulation on T cell activation comprehensive proteome analysis of B7-primed T cell populations were performed. Using this approach we identified different classes of proteins in T cells whose expression is either elevated or reduced upon B7-1- or B7-2-mediated CD28 costimulation. The altered proteins include regulators of the cell cycle and cell proliferation, signal transducers, components of the antigen processing machinery, transporters, cytoskeletal proteins, and metabolic enzymes. A number of differentially expressed proteins are further modified by phosphorylation. Our results provide novel insights into the complexity of the CD28 costimulatory pathway of T cells and will help to identify potential targets of therapeutic interventions for modulating anti-tumor T cell activation.

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