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result(s) for
"Hartmann, Karsten"
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Impact of a synchronous prophylactic treatment of the anterior accessory saphenous vein on the recurrent varicose vein rate in patients undergoing thermal ablation of an insufficient great saphenous vein (SYNCHRONOUS-Study): study protocol for a prospective, multicentre, controlled observational study
by
Müller, Lars
,
Mattausch, Thomas
,
Hartmann, Karsten
in
Ablation
,
Compression therapy
,
Dermatology
2022
IntroductionTo date, there are no prospective studies evaluating the prevention of recurrent veins by the simultaneous treatment of a sufficient anterior accessory saphenous vein (AASV) in patients undergoing endovenous laser ablation (EVLA) of an insufficient great saphenous vein (GSV). This study will provide important information about the impact of the AASV on the development of recurrent veins after EVLA of the GSV. Additionally, it will be clarified whether patients benefit from a preventive ablation of a sufficient AASV.Methods and analysisThis is a multicentre, prospective, controlled, exploratory clinical study in 1150 patients with a medical indication for EVLA of a refluxing great saphenous vein. Patients will be enrolled into two study groups: in half of the patients EVLA will be performed on the insufficient GSV only. In the other half of the patients EVLA will be performed on the insufficient GSV and additionally on the sufficient AASV. Within seven study visits, patients will be followed-up over a time period of 5 years. Primary study endpoint is the recurrence rate; secondary endpoints include inter alia, complication rate, postoperative pain intensity, quality of life and patient satisfaction.Ethics and disseminationBefore initiation of the study, the protocol was presented and approved by the independent ethics committee of the medical faculty of the University of Heidelberg (Ethics approval number S-596/2018). This study was prospectively registered at the German Clinical Trial Register (https://www.germanctr.de/). Research findings will be disseminated in a peer-reviewed journal and at relevant conferences.Trial registration numberGerman Clinical Trial Registry (DRKS00015486).
Journal Article
Efficacy and safety of endovenous laser ablation with the 1470 nm diode laser using a novel optical probe
by
Hartmann, Karsten
,
Gholam, Patrick
,
Dietrich, Carmen
in
Ablation
,
Compression therapy
,
Energy
2022
Outcome assessment of a novel optical fiber probe for the 1470 nm diode laser under real-world conditions.
Prospective clinical pilot study in 10 patients undergoing endovenous laser ablation with a follow-up period of 1 year. Primary endpoints were efficacy and safety. Secondary endpoints include, inter alia, quality of life and patient satisfaction.
After a follow-up period of 1 year all treated vein segments were still occluded. Only mild and short-term side effects (hematoma, ecchymosis and hyperpigmentation) were observed. No intake of pain medication was needed and a quick return to normal activity was documented (0.9 days). Clinical hallmarks of the venous disease (VCSS) improved significantly (p= .003). All patients were very satisfied with the treatment and quality of life (AVVQ) was significantly improved after the procedure (p=.008).
The study demonstrates that the endoluminal treatment with the novel fiber probe is highly effective and safe.
Journal Article
Tumour-infiltrating lymphocytes and prognosis in different subtypes of breast cancer: a pooled analysis of 3771 patients treated with neoadjuvant therapy
by
Kümmel, Sherko
,
Karn, Thomas
,
Schneeweiss, Andreas
in
Biomarkers
,
Breast cancer
,
Cancer therapies
2018
Tumour-infiltrating lymphocytes (TILs) are predictive for response to neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) and HER2-positive breast cancer, but their role in luminal breast cancer and the effect of TILs on prognosis in all subtypes is less clear. Here, we assessed the relevance of TILs for chemotherapy response and prognosis in patients with TNBC, HER2-positive breast cancer, and luminal–HER2-negative breast cancer.
Patients with primary breast cancer who were treated with neoadjuvant combination chemotherapy were included from six randomised trials done by the German Breast Cancer Group. Pretherapeutic core biopsies from 3771 patients included in these studies were assessed for the number of stromal TILs by standardised methods according to the guidelines of the International TIL working group. TILs were analysed both as a continuous parameter and in three predefined groups of low (0–10% immune cells in stromal tissue within the tumour), intermediate (11–59%), and high TILs (≥60%). We used these data in univariable and multivariable statistical models to assess the association between TIL concentration and pathological complete response in all patients, and between the amount of TILs and disease-free survival and overall survival in 2560 patients from five of the six clinical trial cohorts.
In the luminal–HER2-negative breast cancer subtype, a pathological complete response (pCR) was achieved in 45 (6%) of 759 patients with low TILs, 48 (11%) of 435 with intermediate TILs, and 49 (28%) of 172 with high TILs. In the HER2-positive subtype, pCR was observed in 194 (32%) of 605 patients with low TILs, 198 (39%) of 512 with intermediate TILs, and 127 (48%) of 262 with high TILs. Finally, in the TNBC subtype, pCR was achieved in 80 (31%) of 260 patients with low TILs, 117 (31%) of 373 with intermediate TILs, and 136 (50%) of 273 with high TILs (p<0·0001 for each subtype, χ2 test for trend). In the univariable analysis, a 10% increase in TILs was associated with longer disease-free survival in TNBC (hazard ratio [HR] 0·93 [95% CI 0·87–0·98], p=0·011) and HER2-positive breast cancer (0·94 [0·89–0·99], p=0·017), but not in luminal–HER2-negative tumours (1·02 [0·96–1·09], p=0·46). The increase in TILs was also associated with longer overall survival in TNBC (0·92 [0·86–0·99], p=0·032), but had no association in HER2-positive breast cancer (0·94 [0·86–1·02], p=0·11), and was associated with shorter overall survival in luminal–HER2-negative tumours (1·10 [1·02–1·19], p=0·011).
Increased TIL concentration predicted response to neoadjuvant chemotherapy in all molecular subtypes assessed, and was also associated with a survival benefit in HER2-positive breast cancer and TNBC. By contrast, increased TILs were an adverse prognostic factor for survival in luminal–HER2-negative breast cancer, suggesting a different biology of the immunological infiltrate in this subtype. Our data support the hypothesis that breast cancer is immunogenic and might be targetable by immune-modulating therapies. In light of the results in luminal breast cancer, further research investigating the interaction of the immune system with different types of endocrine therapy is warranted.
Deutsche Krebshilfe and European Commission.
Journal Article
Ecophysiological, morphological, and biochemical traits of free-living Diplosphaera chodatii (Trebouxiophyceae) reveal adaptation to harsh environmental conditions
2021
Single-celled green algae within the Trebouxiophyceae (Chlorophyta) are typical components of terrestrial habitats, which often exhibit harsh environmental conditions for these microorganisms. This study provides a detailed overview of the ecophysiological, biochemical, and ultrastructural traits of an alga living on tree bark. The alga was isolated from a cypress tree in the Botanical Garden of Innsbruck (Austria) and identified by morphology and molecular phylogeny as Diplosphaera chodatii. Transmission electron microscopy after high-pressure freezing (HPF) showed an excellent preservation of the ultrastructure. The cell wall was bilayered with a smooth inner layer and an outer layer of polysaccharides with a fuzzy hair-like appearance that could possibly act as cell-cell adhesion mechanism and hence as a structural precursor supporting biofilm formation together with the mucilage observed occasionally. The photosynthetic-irradiance curves of D. chodatii indicated low light requirements without photoinhibition at high photon flux densities (1580 μmol photons m−2 s−1) supported by growth rate measurements. D. chodatii showed a high desiccation tolerance, as 85% of its initial value was recovered after controlled desiccation at a relative humidity of ~10%. The alga contained the low molecular weight carbohydrates sucrose and sorbitol, which probably act as protective compounds against desiccation. In addition, a new but chemically not elucidated mycosporine-like amino acid was detected with a molecular mass of 332 g mol−1 and an absorption maximum of 324 nm. The presented data provide various traits which contribute to a better understanding of the adaptive mechanisms of D. chodatii to terrestrial habitats.
Journal Article
Prasiolin, a new UV-sunscreen compound in the terrestrial green macroalga Prasiola calophylla (Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta)
2016
MAIN CONCLUSION : We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calophylla. Prasiola calophylla (Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasiola species and other related Trebouxiophycean taxa synthesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elucidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M⁻¹ cm⁻¹, and could be identified as N-[5,6 hydroxy-5(hydroxymethyl)-2-methoxy-3-oxo-1-cycohexen-1-yl] glutamic acid using one- and two-dimensional ¹H and ¹³C-NMR spectroscopy. As trivial name for this novel MAA we suggest ‘prasiolin’. The ecologically essential function of prasiolin for UVR-protection in terrestrial algae of the Trebouxiophyceae is discussed.
Journal Article
A Transgenic Probiotic Secreting a Parasite Immunomodulator for Site-Directed Treatment of Gut Inflammation
by
Ebner, Friederike
,
Whelan, Rose A
,
Kühl, Anja A
in
Animals
,
Chemokines - genetics
,
Chemokines - metabolism
2014
New treatment strategies for inflammatory bowel disease are needed and parasitic nematode infections or application of helminth components improve clinical and experimental gut inflammation. We genetically modified the probiotic bacterium Escherichia coli Nissle 1917 to secrete the powerful nematode immunomodulator cystatin in the gut. This treatment was tested in a murine colitis model and on post-weaning intestinal inflammation in pigs, an outbred model with a gastrointestinal system similar to humans. Application of the transgenic probiotic significantly decreased intestinal inflammation in murine acute colitis, associated with increased frequencies of Foxp3+ Tregs, suppressed local interleukin (IL)-6 and IL-17A production, decreased macrophage inflammatory protein-1α/β, monocyte chemoattractant protein -1/3, and regulated upon activation, normal T-cell expressed, and secreted expression and fewer inflammatory macrophages in the colon. High dosages of the transgenic probiotic were well tolerated by post-weaning piglets. Despite being recognized by T cells, secreted cystatin did not lead to changes in cytokine expression or macrophage activation in the colon. However, colon transepithelial resistance and barrier function were significantly improved in pigs receiving the transgenic probotic and post-weaning colon inflammation was reduced. Thus, the anti-inflammatory efficiency of a probiotic can be improved by a nematode-derived immunoregulatory transgene. This treatment regimen should be further investigated as a potential therapeutic option for inflammatory bowel disease.
Journal Article
Phytochemical and Analytical Characterization of Novel Sulfated Coumarins in the Marine Green Macroalga Dasycladus vermicularis (Scopoli) Krasser
2018
The siphonous green algae form a morphologically diverse group of marine macroalgae which include two sister orders (Bryopsidales and Dasycladales) which share a unique feature among other green algae as they are able to form large, differentiated thalli comprising of a single, giant tubular cell. Upon cell damage a cascade of protective mechanisms have evolved including the extrusion of sulfated metabolites which are involved in the formation of a rapid wound plug. In this study, we investigated the composition of sulfated metabolites in Dasycladus vermicularis (Dasycladales) which resulted in the isolation of two phenolic acids and four coumarins including two novel structures elucidated by nuclear magnetic resonance spectroscopy (NMR) as 5,8′-di-(6(6′),7(7′)-tetrahydroxy-3-sulfoxy-3′-sulfoxycoumarin), a novel coumarin called dasycladin A and 7-hydroxycoumarin-3,6-disulfate, which was named dasycladin B. In addition, an analytical assay for the chromatographic quantification of those compounds was developed and performed on a reversed phase C-18 column. Method validation confirmed that the new assay shows good linearity (R2 ≥ 0.9986), precision (intra-day R.S.D ≤ 3.71%, inter-day R.S.D ≤ 7.49%), and accuracy (recovery rates ranged from 104.06 to 97.45%). The analysis of several samples of Dasycladus vermicularis from different collection sites, water depths and seasons revealed differences in the coumarin contents, ranging between 0.26 to 1.61%.
Journal Article
Analysis of Mycosporine-Like Amino Acids in Selected Algae and Cyanobacteria by Hydrophilic Interaction Liquid Chromatography and a Novel MAA from the Red Alga Catenella repens
2015
Mycosporine-like amino acids (MAAs), a group of small secondary metabolites found in algae, cyanobacteria, lichens and fungi, have become ecologically and pharmacologically relevant because of their pronounced UV-absorbing and photo-protective potential. Their analytical characterization is generally achieved by reversed phase HPLC and the compounds are often quantified based on molar extinction coefficients. As an alternative approach, in our study a fully validated hydrophilic interaction liquid chromatography (HILIC) method is presented. It enables the precise quantification of several analytes with adequate retention times in a single run, and can be coupled directly to MS. Excellent linear correlation coefficients (R2 > 0.9991) were obtained, with limit of detection (LOD) values ranging from 0.16 to 0.43 µg/mL. Furthermore, the assay was found to be accurate (recovery rates from 89.8% to 104.1%) and precise (intra-day precision: 5.6%, inter-day precision ≤6.6%). Several algae were assayed for their content of known MAAs like porphyra-334, shinorine, and palythine. Liquid chromatography-mass spectrometry (LC-MS) data indicated a novel compound in some of them, which could be isolated from the marine species Catenella repens and structurally elucidated by nuclear magnetic resonance spectroscopy (NMR) as (E)-3-hydroxy-2-((5-hydroxy-5-(hydroxymethyl)-2-methoxy-3-((2-sulfoethyl)amino)cyclohex-2-en-1-ylidene)amino) propanoic acid, a novel MAA called catenelline.
Journal Article
Getting in control of persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM) substances to protect water resources: strategies from diverse perspectives
by
Schliebner Ivo
,
Letzel, Thomas
,
Neumann, Michael
in
Analytical methods
,
Availability
,
Drinking water
2022
BackgroundSafe and clean drinking water is essential for human life. Persistent, mobile and toxic (PMT) substances and/or very persistent and very mobile (vPvM) substances are an important group of substances for which additional measures to protect water resources may be needed to avoid negative environmental and human health effects. PMT/vPvM substances do not sufficiently biodegrade in the environment, they can travel long distances with water and are toxic (those that are PMT substances) to the environment and/or human health. PMT/vPvM substance research and regulation is arguably in its infancy and in order to get in control of these substances the following (non-exhaustive list of) knowledge gaps should to be addressed: environmental occurrence; the suitability of currently available analytical methods; the effectiveness and availability of treatment technologies; the ability of regional governance and industrial stewardship to contribute to safe drinking water while supporting innovation; the ways in which policies and regulations can be used most effectively to govern these substances; and, the identification of safe and sustainable alternatives.MethodsThe work is the outcome of the third PMT workshop, held in March 2021, that brought together diverse scientists, regulators, NGOs, and representatives from the water sector and the chemical sector, all concerned with protecting the quality of our water resources. The online workshop was attended by over 700 people. The knowledge gaps above were discussed in the presentations given and the attendees were invited to provide their opinions about knowledge gaps related to PMT/vPvM substance research and regulation.ResultsStrategies to closing the knowledge, technical and practical gaps to get in control of PMT/vPvM substances can be rooted in the Chemicals Strategy for Sustainability Towards a Toxic Free Environment from the European Commission, as well as recent advances in the research and industrial stewardship. Key to closing these gaps are: (i) advancing remediation and removal strategies for PMT/vPvM substances that are already in the environment, however this is not an effective long-term strategy; (ii) clear and harmonized definitions of PMT/vPvM substances across diverse European and international legislations; (iii) ensuring wider availability of analytical methods and reference standards; (iv) addressing data gaps related to persistence, mobility and toxicity of chemical substances, particularly transformation products and those within complex substance mixtures; and (v) advancing monitoring and risk assessment tools for stewardship and regulatory compliance. The two most effective ways to get in control were identified to be source control through risk governance efforts, and enhancing market incentives for alternatives to PMT/vPvM substances by using safe and sustainable by design strategies.
Journal Article
Moss-produced human complement factor H with modified glycans has an extended half-life and improved biological activity
by
Dabrowska-Schlepp, Paulina
,
Konwar, Swagata
,
Panse, Jens
in
Animals
,
Binding sites
,
Biological activity
2024
Most drugs that target the complement system are designed to inhibit the complement pathway at either the proximal or terminal levels. The use of a natural complement regulator such as factor H (FH) could provide a superior treatment option by restoring the balance of an overactive complement system while preserving its normal physiological functions. Until now, the systemic treatment of complement-associated disorders with FH has been deemed unfeasible, primarily due to high production costs, risks related to FH purified from donors’ blood, and the challenging expression of recombinant FH in different host systems. We recently demonstrated that a moss-based expression system can produce high yields of properly folded, fully functional, recombinant FH. However, the half-life of the initial variant (CPV-101) was relatively short. Here we show that the same polypeptide with modified glycosylation (CPV-104) achieves a pharmacokinetic profile comparable to that of native FH derived from human serum. The treatment of FH-deficient mice with CPV-104 significantly improved important efficacy parameters such as the normalization of serum C3 levels and the rapid degradation of C3 deposits in the kidney compared to treatment with CPV-101. Furthermore, CPV-104 showed comparable functionality to serum-derived FH in vitro , as well as similar performance in ex vivo assays involving samples from patients with atypical hemolytic uremic syndrome, C3 glomerulopathy and paroxysomal nocturnal hematuria. CPV-104 – the human FH analog expressed in moss – will therefore allow the treatment of complement-associated human diseases by rebalancing instead of inhibiting the complement cascade.
Journal Article