Publications by authors named "Christian Sperling"

7 Publications

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Automated detection of the HER2 gene amplification status in Fluorescence in situ hybridization images for the diagnostics of cancer tissues.

Sci Rep 2019 06 3;9(1):8231. Epub 2019 Jun 3.

Institute of Pathology, University Hospital Carl Gustav Carus (UKD), TU Dresden, Dresden, Germany.

The human epidermal growth factor receptor 2 (HER2) gene amplification status is a crucial marker for evaluating clinical therapies of breast or gastric cancer. We propose a deep learning-based pipeline for the detection, localization and classification of interphase nuclei depending on their HER2 gene amplification state in Fluorescence in situ hybridization (FISH) images. Our pipeline combines two RetinaNet-based object localization networks which are trained (1) to detect and classify interphase nuclei into distinct classes normal, low-grade and high-grade and (2) to detect and classify FISH signals into distinct classes HER2 or centromere of chromosome 17 (CEN17). By independently classifying each nucleus twice, the two-step pipeline provides both robustness and interpretability for the automated detection of the HER2 amplification status. The accuracy of our deep learning-based pipeline is on par with that of three pathologists and a set of 57 validation images containing several hundreds of nuclei are accurately classified. The automatic pipeline is a first step towards assisting pathologists in evaluating the HER2 status of tumors using FISH images, for analyzing FISH images in retrospective studies, and for optimizing the documentation of each tumor sample by automatically annotating and reporting of the HER2 gene amplification specificities.
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http://dx.doi.org/10.1038/s41598-019-44643-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546913PMC
June 2019

Comparative preclinical evaluation of a polymer-free sirolimus-eluting stent in porcine coronary arteries.

Ther Adv Cardiovasc Dis 2019 Jan-Dec;13:1753944719826335

Department of Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow, Augustenburger Platz 1, D-13353 Berlin, Germany.

Background:: Polymer-free drug-eluting stents (DES) without permanent-polymer coating may be associated with rapid vessel healing, providing a rationale to reduce dual-antiplatelet therapy (DAPT). The aim of the current study was to compare vessel healing of a polymer-free sirolimus-eluting stent (PF-SES), its bare metal stent (BMS) analogue to a permanent polymer-based sirolimus-eluting stent (SES) with proven effectiveness in porcine coronary arteries.

Material And Methods:: An ultrathin-strut cobalt-chromium PF-SES, its BMS analogue and an SES with a permanent polymer were used to study vessel healing and their antistenotic potential. Stents were implanted in porcine coronary arteries for histopathologic analysis at 7, 28 and 180 days. In an additional in vitro study, the thrombogenicity of PF-SES was compared with a fluoropolymer-coated everolimus-eluting stent (EES) which demonstrated low stent thrombosis rates in numerous studies.

Results:: In the animal study, neointimal growth and injury scores were minimal and inflammation scores were low in the neointima and adventitia in all study groups. After 28 days, neointimal area was lowest in PF-SES when compared with SES and BMS (1.48 ± 0.55 mm² versus 2.43 ± 0.69 mm² versus 1.90 ± 0.85 mm², respectively, p < 0.05) and endothelialization of luminal surfaces was nearly complete in all groups, though SES show the least coverage with occasional adherent luminal inflammatory cells ( p > 0.05). At 180 days, neointimal area and thickness were most pronounced in SES ( p < 0.05) and comparable with BMS implantations, which were characterized by nearly completed vessel healing. PF-SES and BMS had complete endothelialization, absence of fibrin and sustained low inflammatory reaction when compared with the permanent polymer-based SES (inflammation score: PF-SES 0.41 ± 0.74 versus SES 2.52 ± 1.72 versus BMS 0.30 ± 0.65, respectively, p < 0.05 BMS versus SES). Granuloma formation and fibrin accumulation were most pronounced in SES but did not reach statistical significance, p > 0.05). In the in vitro thrombogenicity study, the PF-SES confirmed comparable antithrombogenic properties with regard to the parameters fibrin and platelet binding, and platelet aggregation when compared with the EES.

Conclusions:: As compared with BMS, the ultrathin-strut cobalt-chromium PF-SES showed similar endothelialization at 28 days and comparable healing characteristics at 180 days efficacious inhibition of neointimal proliferation in porcine coronary arteries with low inflammation responses and a BMS-like endothelialization at 180 days. In addition, in an in vitro model, the PF-SES also confirmed low thrombogenicity as compared with the EES.
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http://dx.doi.org/10.1177/1753944719826335DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6376525PMC
March 2019

Propensity score matched all comers population treated with ultra-thin strut bare metal and sirolimus-probucol coated drug-eluting stents of identical stent architecture.

Catheter Cardiovasc Interv 2018 06 25;91(7):1221-1228. Epub 2017 Sep 25.

Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow, Klinikum.

Objective: The objective of this study was to compare the safety and efficacy of a polymer-free sirolimus coated, ultrathin strut drug eluting stent (PF-SES) to its uncoated bare-metal stent (BMS) platform of identical stent architecture.

Background: Recently published randomized trials comparing BMS to DES with a focus on shortened dual-antiplatelet therapy reported incidences of stent thrombosis (ST) and bleeding complications (LEADERS FREE) in favor of drug eluting stents (DES).

Methods: Data of previously published large-sale, international, single-armed, multicenter, observational studies of ultra-thin PF-SES, and BMS were propensity score (PS) matched for selected lesion morphological and cardiovascular risk factors to compare target lesion revascularization (TLR), myocardial infarction, cardiac death, major adverse cardiac events (MACE), bleeding complications and ST rates. Primary endpoint in both studies was TLR at 9 months.

Results: At 9 months the rates of TLR was significantly lower in the PF-SES group as compared with patients treated with the BMS analogue of identical stent design (1.4% vs. 4.6%, P = 0.005). Likewise the 9-month MACE rates were lower in the PF-SES group (3.2% vs. 8.7%, P = 0.001) whereas there were no differences in the accumulated ST rates (0.5% vs. 1.5%, P = 0.109). Overall accumulated bleeding incidences (BARC 1-5) were not significantly different between PF-SES and BMS patients (1.8% vs. 2.7%, p = 0.388).

Conclusions: PF-SES are superior over analogue BMS of identical stent architecture in daily clinical routine with lower rates of TLR and MACE in a PS-matched, unselected patient population without differences in accumulated ST rates and bleeding frequencies given the currently favored postprocedural comedication (ClinicalTrials.gov Identifier NCT02629575).
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http://dx.doi.org/10.1002/ccd.27306DOI Listing
June 2018

High-throughput sequencing of the entire genomic regions of CCM1/KRIT1, CCM2 and CCM3/PDCD10 to search for pathogenic deep-intronic splice mutations in cerebral cavernous malformations.

Eur J Med Genet 2017 Sep 20;60(9):479-484. Epub 2017 Jun 20.

Department of Human Genetics, University Medicine Greifswald, and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany. Electronic address:

Cerebral cavernous malformations (CCM) are vascular lesions of the central nervous system that can cause headaches, seizures and hemorrhagic stroke. Disease-associated mutations have been identified in three genes: CCM1/KRIT1, CCM2 and CCM3/PDCD10. The precise proportion of deep-intronic variants in these genes and their clinical relevance is yet unknown. Here, a long-range PCR (LR-PCR) approach for target enrichment of the entire genomic regions of the three genes was combined with next generation sequencing (NGS) to screen for coding and non-coding variants. NGS detected all six CCM1/KRIT1, two CCM2 and four CCM3/PDCD10 mutations that had previously been identified by Sanger sequencing. Two of the pathogenic variants presented here are novel. Additionally, 20 stringently selected CCM index cases that had remained mutation-negative after conventional sequencing and exclusion of copy number variations were screened for deep-intronic mutations. The combination of bioinformatics filtering and transcript analyses did not reveal any deep-intronic splice mutations in these cases. Our results demonstrate that target enrichment by LR-PCR combined with NGS can be used for a comprehensive analysis of the entire genomic regions of the CCM genes in a research context. However, its clinical utility is limited as deep-intronic splice mutations in CCM1/KRIT1, CCM2 and CCM3/PDCD10 seem to be rather rare.
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http://dx.doi.org/10.1016/j.ejmg.2017.06.007DOI Listing
September 2017

Novel Sirolimus-Coated Balloon Catheter: In Vivo Evaluation in a Porcine Coronary Model.

Circ Cardiovasc Interv 2016 Apr;9(4):e003543

From the Klinik für Innere Medizin III, Kardiologie, Angiologie und internistische Intensivmedizin, Universitätsklinikum des Saarlandes, Homburg/Saar, Germany (Y.P.C., S.B., B.C., M.B., B.S.); Institut für Radiologie, Charité-Universitätsmedizin Berlin, Campus Mitte, Humboldt Universität zu Berlin, Germany (D.P., B.K., U.S.); and B. Braun Melsungen AG, Berlin, Germany (J.C., M.-C.B., C.S., M.S.).

Background: Limus-eluting stents are dominating coronary interventions, although paclitaxel is the only drug on balloon catheters with proven inhibition of restenosis. Neointimal inhibition by limus-coated balloons has been shown in few animal studies, but data from randomized clinical trials are not available. The aim of the present preclinical studies was to achieve high and persistent sirolimus levels in the vessel wall after administration by a coated balloon.

Methods And Results: Different coating formulations and doses were studied in the porcine coronary model to investigate sirolimus tissue levels at different time points as well as efficacy at 1 month using quantitative coronary angiography and histomorphometry. Loss of the selected coating in the valve, guiding catheter, and blood was low (2±14% of dose). Acute drug transfer to the vessel wall was 14.4±4.6% with the crystalline coating, whereas the amorphous coatings were less effective in this respect. Persistence of sirolimus in the vessel wall until 1 month was 40% to 50% of the transferred drug. At 1-month follow-up, a modest but significant reduction of neointimal growth was demonstrated in a dose range from 4 μg/mm(2) to 2×7 μg/mm(2), for example, maximum neointimal thickness of 0.38±0.13 versus 0.65±0.21 mm in the uncoated control group.

Conclusions: Various sirolimus-coated balloons effectively reduce neointimal proliferation in the porcine coronary model but differ considerably in retention time in the vessel wall. It has to be determined if such a formulation with persistent high vessel concentration will result in a relevant clinical effect.
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http://dx.doi.org/10.1161/CIRCINTERVENTIONS.115.003543DOI Listing
April 2016

Deciphering the molecular profile of plaques, memory decline and neuron loss in two mouse models for Alzheimer's disease by deep sequencing.

Front Aging Neurosci 2014 16;6:75. Epub 2014 Apr 16.

Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen , Goettingen , Germany.

One of the central research questions on the etiology of Alzheimer's disease (AD) is the elucidation of the molecular signatures triggered by the amyloid cascade of pathological events. Next-generation sequencing allows the identification of genes involved in disease processes in an unbiased manner. We have combined this technique with the analysis of two AD mouse models: (1) The 5XFAD model develops early plaque formation, intraneuronal Aβ aggregation, neuron loss, and behavioral deficits. (2) The Tg4-42 model expresses N-truncated Aβ4-42 and develops neuron loss and behavioral deficits albeit without plaque formation. Our results show that learning and memory deficits in the Morris water maze and fear conditioning tasks in Tg4-42 mice at 12 months of age are similar to the deficits in 5XFAD animals. This suggested that comparative gene expression analysis between the models would allow the dissection of plaque-related and -unrelated disease relevant factors. Using deep sequencing differentially expressed genes (DEGs) were identified and subsequently verified by quantitative PCR. Nineteen DEGs were identified in pre-symptomatic young 5XFAD mice, and none in young Tg4-42 mice. In the aged cohort, 131 DEGs were found in 5XFAD and 56 DEGs in Tg4-42 mice. Many of the DEGs specific to the 5XFAD model belong to neuroinflammatory processes typically associated with plaques. Interestingly, 36 DEGs were identified in both mouse models indicating common disease pathways associated with behavioral deficits and neuron loss.
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http://dx.doi.org/10.3389/fnagi.2014.00075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3997018PMC
May 2014

[The discourse on mental disorders in the Hispanic short novel: Amado Nervo's case].

Asclepio 2011 ;63(1):65-88

Universidad Autónoma Metropolitana, México D.F.

The evolution of Amado Nervo's novellas shows a constant communication with the paradigmatic shifts in the field of psychopathology. His metafictional constructs foreground a playful treatment of some of medicine's key ideas. In some cases, the narrow limits of positivistic psychopathology are overcome in order to anticipate notions that obtain scientific status with modern psychology.
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http://dx.doi.org/10.3989/asclepio.2011.v63.i1.486DOI Listing
October 2012