Publications by authors named "Alexander Hofmann"

97 Publications

Comprehensive Characterization of a Mesoporous Cerium Oxide Nanomaterial with High Surface Area and High Thermal Stability.

Langmuir 2021 Mar 16;37(8):2563-2574. Epub 2021 Feb 16.

Institute of Physical Chemistry, Justus-Liebig-University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.

In the present study, the pore space of a mesoporous cerium oxide material is investigated, which forms by the self-assembly of primary particles into a spherical secondary structure possessing a disordered mesopore space. The material under study exhibits quite stable mesoporosity upon aging at high temperatures (800 °C) and is, thus, of potential interest in high-temperature catalysis. Here, different characterization techniques were applied to elucidate the structural evolution taking place between heat treatment at 400 °C and aging at 800 °C, i.e., in a water-containing atmosphere, which is usually detrimental to nanoscaled porosity. The changes in the mesoporosity were monitored by advanced physisorption experiments, including hysteresis scanning, and electron tomography analysis coupled with a 3D reconstruction of the mesopore space. These methods indicate that the 3D spatial arrangement of the primary particles during the synthesis under hydrothermal conditions via thermal hydrolysis is related to the thermal stability of the hierarchical mesopore structure. The assembly of the primary CeO particles (∼4 nm in size) results in an interparticulate space constituting an open 3D mesopore network, as revealed by skeleton analysis of tomography data, being in conformity with hysteresis scanning. At elevated temperatures (800 °C), sinter processes occur resulting in the growth of the primary particles, but the 3D mesopore network and the spherical secondary structure are preserved.
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http://dx.doi.org/10.1021/acs.langmuir.0c02747DOI Listing
March 2021

Influence of the fixation technique on the mechanical properties of human cancellous bone of the femoral head.

Clin Biomech (Bristol, Avon) 2021 Jan 24;82:105280. Epub 2021 Jan 24.

ZESBO - Center for Research on Musculoskeletal Systems, Leipzig University, Semmelweisstrasse 14, D-04103 Leipzig, Germany; Department of Orthopaedic Surgery, Traumatology and Plastic Surgery, University of Leipzig Medical Center, Liebigstrasse 20, D-04103 Leipzig, Germany.

Background: The femoral head is of central importance for the force transmission from the suprapelvic body mass to the lower extremity. However, the condition of the subcortical bone and its mechanical properties in case of pathological changes due to coxarthrosis or femoral head necrosis differ from the healthy condition.

Methods: Fresh femoral heads were gathered during hip total endoprosthesis surgeries and cylindrical cancellous bone samples were extracted with a hollow drill. By means of a uniaxial tensile-compression test system, the compressive strength was determined for two different specimen types (fresh and 24 h storage in acetone). Exemplary tests on an exceptionally large femoral head were performed to compare properties of fresh, fresh-deep-frozen and acetone-stored samples.

Findings: The deformation behaviour and the material parameters determined were very heterogeneous. For most of the specimens, a destructive material test was successfully carried out, i.e. the compressive strength was determined. The average strength of fresh specimens was slightly higher than that of acetone specimens. On the other hand, the average Young's modulus of the acetone specimens was higher than that of the fresh specimens.

Interpretation: The lower Young's moodulus of the fresh samples compared to the acetone samples could indicate a causal effect of the degreasing influence of the acetone. The partly considerable individual differences in compressive strength and failure compression can have patient-specific influencing factors such as constitution and physical fitness as well as causes in the initial pathological condition.
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http://dx.doi.org/10.1016/j.clinbiomech.2021.105280DOI Listing
January 2021

The pathogenesis of heterotopic ossification after traumatic brain injury. A review of current literature.

Acta Orthop Belg 2020 Sep;86(3):369-377

Neurogenic heterotopic ossification (NHO), mostly defined as a benign process of formation of bone outside the skeletal system, after traumatic brain injury (TBI) is a musculoskeletal disorder that causes pain and reduces the range of motion, often leading to marked impairment of quality of life. The pathogenic factors that link the brain and bone and cause the formation of heterotopic bone are largely unknown. This article will try to summarize the current literature on the pathogenesis of NHO and accelerated fracture healing after TBI. The heterotopic formation of bone after TBI seems to be inducted by a complex interplay between local and systemic factors. For all different forms of HO, the same three conditions are required for the formation of ectopic bone : The presence of osteoprogenitor cells, a permissive environment, and a stimulating factor. The osteoprogenitor cells are thought to be of mesenchymal origin, however recent research suggests a possible neural origin. The permissive environment is created mainly by reactions to hypoxia and both local and sensory nerve inflammation. Many possible inducing factors have been described ; the endogenic route is thought to be the most dominant in the stimulation of HO formation after TBI. The pathogenesis of NHO remains largely unknown, recent research, however, has discovered interesting topics for further research and new possible targets in the prevention of NHO.
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September 2020

Increase in non-professional phagocytosis during the progression of cell cycle.

PLoS One 2021 5;16(2):e0246402. Epub 2021 Feb 5.

Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.

Homotypic or heterotypic internalization of another, either living or necrotic cell is currently in the center of research interest. The active invasion of a living cell called entosis and cannibalism of cells by rapidly proliferating cancers are prominent examples. Additionally, normal healthy tissue cells are capable of non-professional phagocytosis. This project studied the relationship between non-professional phagocytosis, individual proliferation and cell cycle progression. Three mesenchymal and two epithelial normal tissue cell lines were studied for homotypic non-professional phagocytosis. Homotypic dead cells were co-incubated with adherent growing living cell layers. Living cells were synchronized by mitotic shake-off as well as Aphidicolin-treatment and phagocytotic activity was analyzed by immunostaining. Cell cycle phases were evaluated by flow cytometry. Mesenchymal and epithelial normal tissue cells were capable of internalizing dead cells. Epithelial cells had much higher non-professional phagocytotic rates than mesenchymal cells. Cells throughout the entire cell cycle were able to phagocytose. The phagocytotic rate significantly increased with progressing cell cycle phases. Mitotic cells regularly phagocytosed dead cells, this was verified by Nocodazole and Colcemid treatment. Taken together, our findings indicate the ability of human tissue cells to phagocytose necrotic neighboring cells in confluent cell layers. The origin of the cell line influences the rate of cell-in-cell structure formation. The higher cell-in-cell structure rates during cell cycle progression might be influenced by cytoskeletal reorganization during this period or indicate an evolutionary anchorage of the process. Recycling of nutrients during cell growth might also be an explanation.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246402PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7864402PMC
February 2021

Focus on fragility fractures of the pelvis.

Eur J Trauma Emerg Surg 2021 Feb;47(1):1-2

Dept. for Traumatology and Orthopaedics, Westpfalz Klinikum Gmbh, Kaiserslautern, Germany.

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http://dx.doi.org/10.1007/s00068-020-01550-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7850991PMC
February 2021

Synthesis and characterisation of boranediyl- and diboranediyl-bridged diplatinum A-frame complexes.

Dalton Trans 2021 Jan 14. Epub 2021 Jan 14.

Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.

A series of boranediyl-bridged diplatinum A-frame complexes, [Pt2X2(μ-BY)(μ-dmpm)2] (X = Cl, Br, I; Y = aryl, alkyl, amino, halo; dmpm = bis(dimethylphosphino)methane), were synthesised by the twofold oxidative addition of BX2Y to [Pt2(nbe)2(μ-dmpm)2] (nbe = norbornene) or to the paddlewheel complex [Pt2(μ-dmpm)3]. Similarly, the addition of B2X2(NMe2)2 (X = Cl, Br) to [Pt2(nbe)2(μ-dmpm)2] provided access to the diborane-1,2-diyl-bridged A-frame complexes [Pt2X2(μ-1,2-B2(NMe2)2)(μ-dmpm)2]. X-ray crystallographic studies of these (BY)n-bridged complexes show structural trends depending on the steric demands of Y and the nature of X. Analysis of higher-order 31P NMR satellites provided information on JP-Pt and JPt-Pt coupling constants, the latter correlating with the PtPt distance. All (di)boranediyl complexes also proved unstable towards (successive) loss of the bridging "BY" unit(s), resulting in the formation of [Pt2X2(μ-dmpm)2].
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http://dx.doi.org/10.1039/d0dt03855eDOI Listing
January 2021

Interfering Peptides Targeting Protein-Protein Interactions in the Ethylene Plant Hormone Signaling Pathway as Tools to Delay Plant Senescence.

Methods Mol Biol 2021 ;2213:71-85

Institute of Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.

Interfering peptides (iPs) have been recognized as valuable substances to specifically target protein-protein interactions (PPIs) in senescence and disease. Although the concept of iPs has been validated for several PPIs in medical and pharmaceutical research, little attention so far has been paid to the enormous potential iPs that may provide to target and control plant growth and developmental processes or plant environmental responses. However, recent research on PPIs in the ethylene signaling pathway has identified the synthetic peptide NOP-1 derived from the nuclear localization signal of ethylene regulator EIN2 as an efficient inhibitor of typical ethylene responses such as ripening, aging, and senescence. Biophysical and biochemical studies on purified recombinant proteins of the ethylene receptor family from various plant species demonstrate that the synthetic peptide binds in the nM-μM range at the plant target. Here, we describe methods to evaluate and quantify the effect of the NOP-1 peptide on flower senescence as a typical ethylene response in the intact plant system. This approach will help to systematically advance our technological capability to delay plant ethylene responses and to expand shelf-life or vase life of fruits and flowers.
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http://dx.doi.org/10.1007/978-1-0716-0954-5_7DOI Listing
January 2021

Optical and Electrical Measurements Reveal the Orientation Mechanism of Homoleptic Iridium-Carbene Complexes.

ACS Appl Mater Interfaces 2020 Nov 9;12(46):51709-51718. Epub 2020 Nov 9.

Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.

Understanding and controlling the driving forces for molecular alignment in optoelectronic thin-film devices is of crucial importance for improving their performance. In this context, the preferential orientation of organometallic iridium complexes is in the focus of research to benefit from their improved light-outcoupling efficiencies in organic light-emitting diodes (OLEDs). Although there has been great progress concerning the orientation behavior for heteroleptic Ir complexes, the mechanism behind the alignment of homoleptic complexes is still unclear yet. In this work, we present a sky-blue phosphorescent dye that shows variable alignment depending on systematic modifications of the ligands bound to the central iridium atom. From an optical study of the transition dipole moment orientation and the electrically accessible alignment of the permanent dipole moment, we conclude that the film morphology is related to both the aspect ratio of the dye and the local electrostatic interaction of the ligands with the film surface during growth. These results indicate a potential strategy to actively control the orientation of iridium-based emitters for the application in OLEDs.
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http://dx.doi.org/10.1021/acsami.0c14613DOI Listing
November 2020

A Peptide Pair Coordinates Regular Ovule Initiation Patterns with Seed Number and Fruit Size.

Curr Biol 2020 Nov 10;30(22):4352-4361.e4. Epub 2020 Sep 10.

Institute for Developmental Genetics, Heinrich-Heine University, University Street 1, D-40225 Düsseldorf, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), University Street 1, D-40225 Düsseldorf, Germany. Electronic address:

Ovule development in Arabidopsis thaliana involves pattern formation, which ensures that ovules are regularly arranged in the pistils to reduce competition for nutrients and space. Mechanisms underlying pattern formation in plants, such as phyllotaxis, flower morphogenesis, or lateral root initiation, have been extensively studied, and genes controlling the initiation of ovules have been identified. However, the fundamental patterning mechanism that determines the spacing of ovule anlagen within the placenta remained unexplored. Using natural variation analysis combined with quantitative trait locus analysis, we found that the spacing of ovules in the developing gynoecium and fruits is controlled by two secreted peptides, EPFL2 and EPFL9 (also known as Stomagen), and their receptors from the ERECTA (ER) family that act from the carpel wall and the placental tissue. We found that a signaling pathway controlled by EPFL9 acting from the carpel wall through the LRR-receptor kinases ER, ERL1, and ERL2 promotes fruit growth. Regular spacing of ovules depends on EPFL2 expression in the carpel wall and in the inter-ovule spaces, where it acts through ERL1 and ERL2. Loss of EPFL2 signaling results in shorter gynoecia and fruits and irregular spacing of ovules or even ovule twinning. We propose that the EPFL2 signaling module evolved to control the initiation and regular, equidistant spacing of ovule primordia, which may serve to minimize competition between seeds or facilitate equal resource allocation. Together, EPFL2 and EPFL9 help to coordinate ovule patterning and thereby seed number with gynoecium and fruit growth through a set of shared receptors.
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http://dx.doi.org/10.1016/j.cub.2020.08.050DOI Listing
November 2020

Ring expansion of alumoles with organic azides: selective formation of six-membered aluminum-nitrogen heterocycles.

Chem Sci 2020 Jun 14;11(21):5559-5564. Epub 2020 May 14.

Institute for Inorganic Chemistry , Institute for Sustainable Chemistry & Catalysis with Boron , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany . Email:

Aside from simple Lewis acid-base chemistry, the reaction chemistry of aluminacyclopentadienes, which are commonly referred to as aluminoles or simply alumoles, remains relatively underdeveloped. To date, few attempts to extend their inherent insertion and cycloaddition reactivity to the construction of stable aluminum-containing heterocycles have been reported. Herein, we demonstrate the selective ring expansion of a cyclopentadienyl-substituted alumole with a series of organic azides to form unsaturated six-membered AlN heterocycles. Depending on the substituent on the azide, the reaction proceeds either with or without loss of dinitrogen, leading to incorporation of only the "NR" unit of the azide or the entire azo substituent into the periphery of the heterocycle. A deeper understanding of these ring expansion reactions is reached through computational studies, illustrating deviations in the mechanism as a function of the organic azide employed.
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http://dx.doi.org/10.1039/d0sc02032jDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7444475PMC
June 2020

Isolated Pubic Ramus Fractures Are Serious Adverse Events for Elderly Persons: An Observational Study on 138 Patients with Fragility Fractures of the Pelvis Type I (FFP Type I).

J Clin Med 2020 Aug 3;9(8). Epub 2020 Aug 3.

Department of Orthopedics and Traumatology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

Background: Fractures of the pubic ramus without involvement of the posterior pelvic ring represent a minority of fragility fractures of the pelvis (FFP). The natural history of patients suffering this FFP Type I has not been described so far.

Material And Methods: All patients, who were admitted with isolated pubic ramus fractures between 2007 and mid-2018, have been reviewed. Epidemiologic data, comorbidities, in-hospital complications, and one-year mortality were recorded. Of all surviving patients, living condition before the fracture and at follow-up was noted. Mobility was scored with the Parker Mobility Score, quality of life with the European Quality of Life 5 Dimensions 3 Level (EQ-5D-3L), subjective sensation of pain with the Numeric Rating Scale (NRS).

Results: A consecutive series of 138 patients was included in the study. There were 117 women (84.8%) and 21 men (15.2%). Mean age was 80.6 years (SD 8.6 years). 89.1% of patients presented with comorbidities, 81.2% of them had cardiovascular diseases. Five patients (4%) died during hospital-stay. Median in-hospital stay was eight days (2-45 days). There were in-hospital complications in 16.5%, urinary tract infections, and pneumonia being the most frequent. One-year mortality was 16.7%. Reference values for the normal population of the same age are 5.9% for men and 4.0% for women. One-year mortality rate was 22.2% in the patient group of 80 years or above and 8.8% in the patient group below the age of 80. The rate of surviving patients living at home with or without assistance dropped from 80.5% to 65.3%. The median EQ-5D-Index Value was 0.62 (0.04-1; IQR 0.5-0.78). Reference value for the normal population is 0.78. Average PMS was 4 and NRS 3. Within a two-year period, additional fragility fractures occurred in 21.2% and antiresorptive medication was taken by only 45.2% of patients.

Conclusion: Pubic ramus fractures without involvement of the posterior pelvis (FFP Type I) are serious adverse events for elderly persons. During follow-up, there is an excess mortality, a loss of independence, a restricted mobility, and a decreased quality of life. Pubic ramus fractures are indicators for the need to optimize the patient's general condition.
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http://dx.doi.org/10.3390/jcm9082498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463797PMC
August 2020

Open reduction and internal fixation of acetabular fractures in patients of old age.

Int Orthop 2020 10 30;44(10):2123-2130. Epub 2020 Jul 30.

Department of Orthopaedics and Traumatology, Westpfalz Klinikum Kaiserslautern, Hellmut-Hartert Straße 1, 67655, Kaiserslautern, Germany.

Material And Methods: There is an ongoing debate on which treatment for acetabular fractures in elderly patients is the most appropriate. This study was set up to identify the role of open reduction and internal fixation of acetabular fractures in persons of old age. We retrospectively reviewed the medical charts and radiological data of all patients older than 65 years, who suffered an isolated acetabular fracture and were admitted in our Department between 2010 and 2014 (5-year period). Complications, outcome and mortality were recorded. Of all surviving patients, quality of life (QoL), mobility and independence were graded with European Quality of Life 5 Dimensions 3 Level (EQ-5D-3L), European Quality of Life 5 Dimensions Visual Analogue Scale (EQ-5D-VAS), Numeric Rating Scale (NRS), Elderly Mobility Scale (EMS) and Tinetti Mobility Test (TMT).

Results: Seventy patients could be identified. There were 52 men (74%) and 18 women (26%) with a median age of 79.0 years (range: 65-104 years). Forty-six patients (66%) had been treated with open reduction and internal fixation (ORIF), 24 (34%) conservatively. There were negative predictive factors-subchondral impaction, damage to the femoral head and multiple fragments-in 54% of the operative group. With ORIF, an anatomical reduction could be achieved in 27 patients (59%), an acceptable in 18 (39%) and a poor in one (2%). At follow-up, 18 patients (26%) had died and 23 (33%) were not able to participate. The follow-up rate of the surviving operatively treated patients was 77%. Eleven of 46 operated patients (24%) needed a conversion to a total hip arthroplasty (THA). All patients undergoing conversion had imperfect reduction after surgery. No patient in the non-operative group underwent conversion to THA during follow-up. The median follow-up time of operatively treated patients without conversion (n = 17) was 30 months (range, 16-73 months), of patients with THA (n = 9) 30 months after conversion (range, 17-55 months). Quality of reduction correlated to QoL, mobility and independence in all recorded parameters. Patients with secondary THA had similar good outcomes as patients after ORIF without later conversion. Men had better outcome than women.

Conclusion: ORIF of acetabular fractures in patients of old age results in excellent outcomes at short-term follow-up when anatomical reduction can be achieved. In case of negative predictive factors, ORIF cannot be regarded as a definitive solution, rather as the construction of a stable socket for secondary THA. The decision of therapy should be made dependent on pre-operative radiographic parameters.
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http://dx.doi.org/10.1007/s00264-020-04672-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584535PMC
October 2020

Planar Cyclopenten-4-yl Cations: Highly Delocalized π Aromatics Stabilized by Hyperconjugation.

Angew Chem Int Ed Engl 2020 Oct 25;59(42):18809-18815. Epub 2020 Aug 25.

Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.

Theoretical studies predicted the planar cyclopenten-4-yl cation to be a classical carbocation, and the highest-energy isomer of C H . Hence, its existence has not been verified experimentally so far. We were now able to isolate two stable derivatives of the cyclopenten-4-yl cation by reaction of bulky alanes Cp AlBr with AlBr . Elucidation of their (electronic) structures by X-ray diffraction and quantum chemistry studies revealed planar geometries and strong hyperconjugation interactions primarily from the C-Al σ bonds to the empty p orbital of the cationic sp carbon center. A close inspection of the molecular orbitals (MOs) and of the anisotropy of current (induced) density (ACID), as well as the evaluation of various aromaticity descriptors indicated distinct aromaticity for these cyclopenten-4-yl derivatives, which strongly contrasts the classical description of this system. Here, strong delocalization of π electrons spanning the whole carbocycle has been verified, thus providing rare examples of π aromaticity involving saturated sp carbon atoms.
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http://dx.doi.org/10.1002/anie.202009644DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7589364PMC
October 2020

Peering into the Formation of Cerium Oxide Colloidal Particles in Solution by In Situ Small-Angle X-ray Scattering.

Langmuir 2020 Aug 30;36(31):9175-9190. Epub 2020 Jul 30.

Institute of Physical Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany.

The formation of CeO colloidal particles upon heating an aqueous solution of (NH)Ce(NO) to 100 °C was investigated by time-resolved in situ SAXS analysis using synchrotron radiation, providing absolute intensity data. In particular, the experiments were performed by applying different temperatures between room temperature and 100 °C as well as under variation of the ionic strength and concentration. Using validated SAXS evaluation tools ( and software), the analyses revealed the presence of two types of particle populations possessing average dimensions of ca. 2 nm and 5-15 nm, with the latter being agglomerates of the 2 nm particles rather than single crystallites. The analysis revealed not only the changes in the size, but also the relative volume fractions of these two CeO particle populations as a function of the aforementioned parameters. Increasing the temperature increases the number of the 5-15 nm agglomerates on one hand by the enhanced nucleation rate of the primary particles. On the other hand, especially at high temperatures (90 and 100 °C) the larger agglomerate particles precipitate, resulting in interesting trends in the fractions of the two populations as a function of time, temperature, ionic strength, and precursor concentration. The experimental studies are complemented by calculating colloidal interaction energies based on classical DLVO theory. Thereby, this study provides detailed insight into the nucleation, growth, and agglomeration of CeO nanoparticles. The primary objective of this study is to provide a better understanding of the nucleation and growth of particles by the hydrolysis of the tetravalent cerium ion in aqueous solutions.
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http://dx.doi.org/10.1021/acs.langmuir.0c01463DOI Listing
August 2020

Transition-metal-carbene-like intermolecular insertion of a borylene into C-H bonds.

Chem Commun (Camb) 2020 Jul;56(53):7277-7280

Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.

We demonstrate that, in analogy to transition-metal carbene chemistry, [(OC)5Mo[double bond, length as m-dash]BN(SiMe3)2] facilitates intermolecular transfer of the borylene [:BN(SiMe3)2], which ultimately undergoes insertion into C-H bonds under very mild conditions. The one-pot multiple functionalization of the cyclopentadienyl rings of tungstenocene dihydride is demonstrated using this approach.
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http://dx.doi.org/10.1039/d0cc03075aDOI Listing
July 2020

Tibial plateau fracture: does fracture classification influence the choice of surgical approach? A retrospective multicenter analysis.

Eur J Trauma Emerg Surg 2020 May 15. Epub 2020 May 15.

Department of Orthopedics, Trauma and Spine Surgery, Asklepios Hospital Hamburg Altona, Paul-Ehrlich-Straße 1, 22763, Hamburg, Germany.

Purpose: The role of classification systems for the choice of surgical approach and the management of tibial plateau fractures remains unclear. The purpose of this study was to investigate the potential of classification systems to choose the appropriate operative approach. Current surgical management strategies were investigated in a large multicenter assessment.

Methods: In this study, we retrospectively analyzed all patients with tibial plateau fractures that have received surgical treatment in one of the five Level I trauma facilities between 2012 and 2015. Fractures were classified in each center by a senior orthopedic surgeon using the AO/OTA and the Luo classification. Demographics, trauma mechanism, as well as the surgical approach were recorded.

Results: 538 patients (46.1% male, 53.9% female) were included. The anterolateral approach was used most frequently with 54.8% of all single approaches; 76.2% of all combined approaches used anterolateral as part of the approach. Combined approaches were used in 22.5% of the cases; a combination of the anterolateral and medial (10%), anterolateral, and posteromedial approach (5.8%) were used most frequently. The lowest number was found for the posterolateral (1.3%) and the combined approaches dorsal/anterolateral and medial/dorsal (1.7%, 1.1%). The AO/OTA classification showed a peak for 41.B2 (21.9%) and B3 (35.5%) fractures. Regarding the Luo classification, the dorsal column was involved in 45.7%. In contrast, only 14.7% of the surgical approaches used were able to address the dorsal tibial plateau potentially.

Conclusion: The use of dorsal approach seems to be of minor importance than expected in daily clinical practice in this multicenter study. It was not possible to specify whether the AO/OTA or the Luo classification can reliably predict the choice of surgical approach. The operative treatment strategy of tibial plateau fractures seems to rather rely on the surgeons' experience, education, and preferences.
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http://dx.doi.org/10.1007/s00068-020-01388-zDOI Listing
May 2020

The hydrophobic effect characterises the thermodynamic signature of amyloid fibril growth.

PLoS Comput Biol 2020 05 4;16(5):e1007767. Epub 2020 May 4.

Computer Science Department, Center for Integrative Bioinformatics (IBIVU), VU University, Amsterdam, The Netherlands.

Many proteins have the potential to aggregate into amyloid fibrils, protein polymers associated with a wide range of human disorders such as Alzheimer's and Parkinson's disease. The thermodynamic stability of amyloid fibrils, in contrast to that of folded proteins, is not well understood: the balance between entropic and enthalpic terms, including the chain entropy and the hydrophobic effect, are poorly characterised. Using a combination of theory, in vitro experiments, simulations of a coarse-grained protein model and meta-data analysis, we delineate the enthalpic and entropic contributions that dominate amyloid fibril elongation. Our prediction of a characteristic temperature-dependent enthalpic signature is confirmed by the performed calorimetric experiments and a meta-analysis over published data. From these results we are able to define the necessary conditions to observe cold denaturation of amyloid fibrils. Overall, we show that amyloid fibril elongation is associated with a negative heat capacity, the magnitude of which correlates closely with the hydrophobic surface area that is buried upon fibril formation, highlighting the importance of hydrophobicity for fibril stability.
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http://dx.doi.org/10.1371/journal.pcbi.1007767DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282669PMC
May 2020

Treatment of Severe Kyphoscoliosis in Children with Mucopolysaccharidosis Type I (Pfaundler-Hurler Syndrome) Using the Growing Rod Technique: A Case Series with Mid-Term Results.

World Neurosurg 2020 07 18;139:169-174. Epub 2020 Apr 18.

Department of Orthopedics, Trauma, and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany. Electronic address:

Background: Patients with mucopolysaccharidosis type I (MPS I) have a good life expectancy due to early therapeutic options, such as stem cell therapy. Stem cell therapy can prevent the progression of some skeletal malformations. In contrast, the progression of thoracolumbar kyphoscoliosis, genua vara, and hip dysplasia cannot be influenced. We present 3 cases of children with MPS I with thoracolumbar kyphosis/kyphoscoliosis treated with a growing rod system.

Case Description: The medical records and radiologic imaging of 3 children with a diagnosis of MPS I and kyphosis/kyphoscoliosis of the lumbar spine treated between 2007 and 2019 were retrospectively analyzed. Two children presented with a kyphoscoliosis, and 1 child had a combination of severe anterolisthesis and kyphoscoliosis. Surgery to correct the kyphosis and dorsal stabilization was performed in all patients after exhausted conservative treatment. There were no neurologic complications. Postoperative treatment and aftercare included a corset for 4 months and physical therapy. In all 3 patients, distraction surgery of the lumbar stabilization was done twice at a mean interval of 1 year.

Conclusions: If conservative treatment fails and surgery is necessary, an individual approach is needed. Dorsal stabilization with pedicle screws using a growing rod technique is an option for the correction of thoracolumbar/lumbar kyphosis in children with MPS I. However, fusion should be prevented initially or should be kept as short as possible. We achieved acceptable correction of the spinal deformity using the growing rod technique. Finally, surgery with correction and fusion is necessary after exhausted correction potential.
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http://dx.doi.org/10.1016/j.wneu.2020.04.055DOI Listing
July 2020

Safety and efficacy of 2D-fluoroscopy-based iliosacral screw osteosynthesis: results of a retrospective monocentric study.

Eur J Trauma Emerg Surg 2020 Apr 15. Epub 2020 Apr 15.

Department of Orthopaedics and Traumatology, Fulda Clinic, Pacelliallee 4, 36043, Fulda, Germany.

Introduction: Iliosacral screw osteosynthesis is a well-accepted procedure for stabilization of sacral fractures and iliosacral (fracture) dislocations.

Materials And Methods: In this monocentric study, safety and efficacy of conventional 2D-fluoroscopic-guided iliosacral screw insertion were evaluated.

Results: During a 10-year period (2005-2014), 98 patients between the age of 18 and 65 years received 207 iliosacral screws in 101 procedures. Average patient age was 43.2 years. There were 46 Type B and 40 Type C injuries in the AO/OTA classification, nine patients had a fragility fracture of the pelvis. In three patients, primary radiological data were missing. The indication for surgical treatment was a sacral fracture in 97 patients, a pure iliosacral dislocation in 37 patients and a fracture-dislocation in 31 patients. 70 procedures were performed with the patient in supine position, 31 with the patient in prone position. Surgery was done in a minimal-invasive technique in 76 patients, in 22 patients an open reduction was necessary before screw insertion. 81 patients received a unilateral, 17 patients a bilateral screw osteosynthesis. 199 screws were inserted in S1, only eight screws in S2. 65 patients received two screws unilaterally, ten patients two screws bilaterally. There were no vascular or neurologic complications. During in-hospital stay, there were seven complications, which needed 12 operative revisions: three wound infections, two hematomas, one screw malalignment and one early screw loosening. In 28 patients with 56 iliosacral screws, a pelvic CT-scan was performed during follow-up. A penetration of a cortical layer was diagnosed in 20 of these screws. All penetrations were seen in double screw osteosynthesis of S1. In none of the patients, complaints could be explained by the malalignment of these screws. Five operative revisions were performed during follow-up: two for screw loosening, two for fracture healing problems and one for screw malalignment. Metal removal was performed in 39 patients with 75 screws. 2D-fluoroscopic-guided iliosacral screw osteosynthesis is a safe and efficient procedure in clinical practice.

Discussion: A thorough preoperative evaluation of the morphology of the upper sacrum and careful operative procedure are indispensable. Fluoroscopic views in AP, lateral, inlet and outlet must allow recognition of all anatomical landmarks. The indication for double screw osteosynthesis in S1 should be taken with caution. Screw malalignments do not inevitably correlate with complaints.
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http://dx.doi.org/10.1007/s00068-020-01362-9DOI Listing
April 2020

Boranediyl- and Diborane(4)-1,2-diyl-Bridged Platinum A-Frame Complexes.

Chemistry 2020 Jul 17;26(39):8518-8523. Epub 2020 Jun 17.

Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Wüzburg, Am Hubland, 97074, Würzburg, Germany.

Diplatinum A-frame complexes with a bridging (di)boron unit in the apex position were synthesized in a single step by the double oxidative addition of dihalo(di)borane precursors at a bis(diphosphine)-bridged Pt complex. While structurally analogous to well-known μ-borylene complexes, in which delocalized dative three-center-two-electron M-B-M bonding prevails, theoretical investigations into the nature of Pt-B bonding in these A-frame complexes show them to be rare dimetalla(di)boranes displaying two electron-sharing Pt-B σ-bonds. This is experimentally reflected in the low kinetic stability of these compounds, which are prone to loss of the (di)boron bridgehead unit.
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http://dx.doi.org/10.1002/chem.202001168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7384048PMC
July 2020

High-Level Expression, Purification and Initial Characterization of Recombinant Histidine Kinase AHK1.

Plants (Basel) 2020 Mar 1;9(3). Epub 2020 Mar 1.

Institute of Biochemical Plant Physiology, Heinrich Heine University, Düsseldorf 40225, Germany.

Plants employ a number of phosphorylation cascades in response to a wide range of environmental stimuli. Previous studies in and yeast indicate that histidine kinase AHK1 is a positive regulator of drought and osmotic stress responses. Based on these studies AHK1 was proposed a plant osmosensor, although the molecular basis of plant osmosensing still remains unknown. To understand the molecular role and signaling mechanism of AHK1 in osmotic stress, we have expressed and purified full-length AHK1 from in a bacterial host to allow for studies on the isolated transmembrane receptor. Purification of the recombinant protein solubilized from the host membranes was achieved in a single step by metal-affinity chromatography. Analysis of the purified AHK1 by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting show a single band indicating that the preparation is highly pure and devoid of contaminants or degradation products. In addition, gel filtration experiments indicate that the preparation is homogenous and monodisperse. Finally, CD-spectroscopy, phosphorylation activity, dimerization studies, and protein-protein interaction with plant phosphorylation targeting AHP2 demonstrate that the purified protein is functionally folded and acts as phospho-His or phospho-Asp phosphatase. Hence, the expression and purification of recombinant AHK1 reported here provide a basis for further detailed functional and structural studies of the receptor, which might help to understand plant osmosensing and osmosignaling on the molecular level.
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http://dx.doi.org/10.3390/plants9030304DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7154865PMC
March 2020

Minimal-invasive stabilization of anterior pelvic ring fractures with retrograde transpubic screws.

Injury 2020 Feb 16;51(2):340-346. Epub 2019 Dec 16.

Department of Orthopaedics and Traumatology, University Medical Center Mainz, Mainz, Germany. Electronic address:

Background: In the vast majority of patients with pelvic ring lesions, there is a combination of fractures of the posterior and anterior pelvic ring. Anterior fractures are painful and contribute to loss of stability of the pelvic ring. For these reasons, stabilization of pubic rami fractures is recommended together with posterior pelvic ring fixation. Retrograde transpubic screw osteosynthesis enjoys increasing acceptance due to its minimal invasive technique and adequate stability.

Patients And Methods: We retrospectively reviewed the results of 158 retrograde transpubic screw osteosyntheses in 128 patients with pelvic ring lesions including a pubic ramus fracture. Sixty-three patients suffered a high-energy injury, 65 a fragility fracture of the pelvis.

Results: One hundred and forty-six screws (92.4%) were inserted through a percutaneous procedure. There were no vascular, neurological or urological complications. Fifty-nine screws (39%) yielded an excellent reduction with less than one cortical width of displacement. Slight secondary displacement was seen in 33 of these fractures (55.9%). Early surgical complications were seen in 16 screws (10.1%): suboptimal pathway in 10, local hematoma in 4 and local infection in 3. Early revision surgery was done in 7 screws (4.4%). Median follow-up was 27.6 weeks, 83 screws (52.5%) had a follow-up of more than 6 months. During follow-up, 7.6% of screws loosened. Operative revision was performed in 13%. 75 fractures (90.3%) with a follow-up of ≥ 6 months showed radiographic evidence of healing. There was no difference in the healing rate of high-energy and fragility fractures. Nonunion rate was not dependent on the quality of primary reduction, secondary displacement, or screw loosening. Infection (p 0.001) and surgery ≥ 6 months after trauma (p 0.02) more often led to nonunion.

Conclusion: Retrograde transpubic screw osteosynthesis is a reliable method for splinting pubic rami fractures in high and low energy pelvic trauma. Although a slight secondary fracture displacement is seen in most cases, it does not affect fracture healing. Retrograde transpubic screw is a adequate minimal-invasive osteosynthesis to stabilize the anterior pelvic ring, especially in fragility fracture of the pelvis. Delayed operation (> 6 months) and infection show higher rate of nonunion.
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http://dx.doi.org/10.1016/j.injury.2019.12.018DOI Listing
February 2020

Traumatic brain injury enhances the formation of heterotopic ossification around the hip: an animal model study.

Arch Orthop Trauma Surg 2020 Aug 13;140(8):1029-1035. Epub 2019 Dec 13.

Department of Orthopaedics and Trauma Surgery, University Hospital Mainz, Langenbeckstraße 1, 55131, Mainz, Germany.

Introduction: The incidence of heterotopic ossification (HO) is at its highest when trauma of the hip or pelvis concurs with traumatic brain injury (TBI). The pathogenic mechanisms underlying the neurogenic enhancement of the formation of HO remain, however, poorly understood. Hence, the goal of the present study was to develop a novel small animal model that combines hip and brain trauma that can prove the enhancement of HO around the hip after TBI.

Materials And Methods: Forty male Wistar rats were divided into four groups, to undergo hip surgery alone (group 1), hip surgery + moderate TBI (group 2), hip surgery + severe TBI (group 3) and only severe TBI (group 4). The femoral canal was reamed up to 2 mm and a muscle lesion was made to simulate hip surgery. An established controlled cortical impact model was used to create a TBI. Twelve weeks after surgery, the hip with the proximal half of the femur and the pelvic bone was removed and subjected to micro-computed tomography (µCT) analysis. A quantitative analysis using a modified Brooker score as well as a quantitative analysis using a bone-to-tissue ratio was used.

Results: No HO could be found in all the ten animals that did not undergo hip surgery (group 4). In the animals that did undergo surgery to the hip, no HO was found in only one animal (group 1). All the other animals developed HO. In this study, significantly more HO was found in animals that underwent an additional severe TBI.

Conclusion: The newly developed rat model, with a combined hip and brain trauma, showed an enhancement of the HO formation around the hip after severe TBI.
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http://dx.doi.org/10.1007/s00402-019-03326-0DOI Listing
August 2020

Autologous Iliac Bone Graft Compared with Biphasic Hydroxyapatite and Calcium Sulfate Cement for the Treatment of Bone Defects in Tibial Plateau Fractures: A Prospective, Randomized, Open-Label, Multicenter Study.

J Bone Joint Surg Am 2020 02;102(3):179-193

Department of Orthopedics and Traumatology, University Medical Center Mainz, Mainz, Germany.

Background: Bone-graft substitutes are commonly used for the augmentation of traumatic bone defects in tibial plateau fractures. However, their clinical performance compared with that of autologous bone-grafting, the gold standard in bone defect reconstruction, still remains under debate. This study investigates the differences in quality of life, pain, and radiographic outcomes in the treatment of tibial plateau fracture-associated bone defects with either autologous bone grafts or a bioresorbable hydroxyapatite and calcium sulfate cement (CERAMENT BONE VOID FILLER [CBVF]; BONESUPPORT).

Methods: In this study, 135 patients with acute depression and split-depression fractures of the proximal part of the tibia (OTA/AO types 41-B2 and 41-B3) were enrolled in a prospective, controlled, randomized, multicenter trial including 20 hospitals in Germany. Patients were randomized to receive either autologous iliac bone graft or CBVF for reconstruction of the bone defect. The primary outcome measures were the Short Form (SF)-12 version 2 Physical Component Summary (PCS) score at week 26 (the study was designed to show noninferiority of the CBVF with regard to the PCS with a prespecified margin of -5 points) and the pain level at 26 weeks postoperatively measured by a visual analog scale (VAS). The secondary outcomes were the SF-12 version 2 Mental Component Summary (MCS) and SF-12 PCS scores at weeks 1, 6, and 12 and bone-healing on radiographs.

Results: Age, sex, fixation methods, and fracture pattern were comparable in both groups. There were no significant differences (p > 0.05) in the SF-12 PCS or VAS scores at postoperative week 26. There was a significant reduction of blood loss (p = 0.007) and pain levels (p = 0.008) at postoperative day 1 in the CBVF group. The rates of fracture-healing, defect remodeling, and articular subsidence were not significantly different (p > 0.05) in both groups.

Conclusions: Bioresorbable CBVF was noninferior to autologous bone graft with regard to both patient-reported and radiographic outcomes in tibial plateau fractures of OTA/AO types 41-B2 and 41-B3.

Level Of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.2106/JBJS.19.00680DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7508276PMC
February 2020

trans-Selective Insertional Dihydroboration of a cis-Diborene: Synthesis of Linear sp -sp -sp -Triboranes and Subsequent Cationization.

Angew Chem Int Ed Engl 2020 Jan 12;59(1):325-329. Epub 2019 Nov 12.

Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Wüzburg, Am Hubland, 97074, Würzburg, Germany.

The reaction of aryl- and amino(dihydro)boranes with dibora[2]ferrocenophane 1 leads to the formation 1,3-trans-dihydrotriboranes by formal hydrogenation and insertion of a borylene unit into the B=B bond. The aryltriborane derivatives undergo reversible photoisomerization to the cis-1,2-μ-H-3-hydrotriboranes, while hydride abstraction affords cationic triboranes, which represent the first doubly base-stabilized B H analogues.
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http://dx.doi.org/10.1002/anie.201911645DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6972689PMC
January 2020

Effects of losartan and atorvastatin on the development of early posttraumatic joint stiffness in a rat model.

Drug Des Devel Ther 2019 30;13:2603-2618. Epub 2019 Jul 30.

Department of Orthopaedics and Traumatology, Biomatics Group, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany.

Background: After a trauma, exuberant tissue healing with fibrosis of the joint capsule can lead to posttraumatic joint stiffness (PTJS). Losartan and atorvastatin have both shown their antifibrotic effects in different organ systems.

Objective: The purpose of this study was the evaluation of the influence of losartan and atorvastatin on the early development of joint contracture. In addition to joint angles, the change in myofibroblast numbers and the distribution of bone sialoprotein (BSP) were assessed.

Study Design And Methods: In this randomized and blinded experimental study with 24 rats, losartan and atorvastatin were compared to a placebo. After an initial joint injury, rat knees were immobilized with a Kirschner wire. Rats received either losartan, atorvastatin or a placebo orally daily. After 14 days, joint angle measurements and histological assessments were performed.

Results: Losartan increased the length of the inferior joint capsule. Joint angle and other capsule length measurements did not reveal significant differences between both drugs and the placebo. At cellular level both losartan and atorvastatin reduced the total number of myofibroblasts (losartan: 191±77, atorvastatin: 98±58, placebo: 319±113 per counting field, <0.01) and the percentage area of myofibroblasts (losartan: 2.8±1.8% [<0.05], atorvastatin: 2.5±1.7% [<0.01], vs control [6.4±4%], respectively). BSP was detectable in equivalent amounts in the joint capsules of all groups with only a trend toward a reduction of the BSP-stained area by atorvastatin.

Conclusion: Both atorvastatin and losartan reduced the number of myofibroblasts in the posterior knee joint capsule of rat knees 2 weeks after trauma and losartan increased the length of the inferior joint capsule. However, these changes at the cellular level did not translate an increase in range of motion of the rats´ knee joints during early contracture development.
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http://dx.doi.org/10.2147/DDDT.S204135DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6679684PMC
April 2020

Short-term hypoxia promotes vascularization in co-culture system consisting of primary human osteoblasts and outgrowth endothelial cells.

J Biomed Mater Res A 2020 01 17;108(1):7-18. Epub 2019 Sep 17.

Institute of Pathology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.

Prevascularization of tissue constructs before implantation has been developed as a novel and promising concept for successful implantation. Since hypoxia might induce angiogenesis, we have investigated the effects of hypoxic treatment on vascularization by using co-cultures of primary human osteoblasts (POBs) and outgrowth endothelial cells. Our results show that: (a) repeated short-term hypoxia (2% O for 8 hr), not long-term hypoxia (2% O for 24 hr), over 1 or 2 weeks, significantly enhances microvessel formation in co-cultures; (b) sustained hypoxia, not short-term or long-term hypoxia, causes cytotoxicity in mono- and co-cultures; (c) the expression of some angiogenic and inflammatory factors such as vascular endothelial growth factor, platelet-derived growth factor subunit B, insulin-like growth factor 1, interleukin-8, and early growth response protein 1 increases significantly in hypoxia-treated POB monoculture and co-cultures after single or multiple 8- or 24-hr hypoxic treatments; (d) long-term (24 hr) hypoxic treatment induces more angiogenic inhibitors compared with short-term hypoxic treatment. Our findings suggest that hypoxia-induced vascularization/angiogenesis is regulated by a complex balance of angiogenic/antiangiogenic factors, and that repeated short-term hypoxia, but not repeated long-term hypoxia, promotes the vascularization and tissue regeneration of bone tissue constructs.
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http://dx.doi.org/10.1002/jbm.a.36786DOI Listing
January 2020

[Complex treatment of pyoderma gangrenosum after minor trauma and primary surgical intervention with suspected necrotizing fasciitis].

Unfallchirurg 2020 Jan;123(1):68-75

Klinik und Poliklinik für Orthopädie, Unfallchirurgie und Plastische Chirurgie, Universitätsklinikum Leipzig, Liebigstr. 20, 04103, Leipzig, Deutschland.

This article presents the case of a rapidly progressing pyoderma gangrenosum (PG) following a minor trauma and surgical intervention. A 46-year-old patient was admitted to hospital after a minor trauma of the right lower leg with a suspected diagnosis of erysipelas bullosum. A magnetic resonance imaging (MRI) scan showed the suspicion of necrotizing fasciitis (NF) with indications for immediate incision and fascia resection. According to the results of the histopathological analysis and microbiological assessment without signs for a bacterial infection, high-dose steroid treatment and immunosuppressive treatment with cyclosporin A were initiated under the assumption of PG. Additionally, the patient was treated with hyperbaric oxygenation (HBO). The 2‑year follow-up showed a gradual restitution of the soft tissues.
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http://dx.doi.org/10.1007/s00113-019-00704-6DOI Listing
January 2020

Asthma control in children: Body plethysmography in addition to spirometry.

Pediatr Pulmonol 2019 08 6;54(8):1141-1148. Epub 2019 Jun 6.

Department of Pediatric Cardiology and Intensive Care Medicine with Neonatology and Pediatric Pneumology, University Hospital Goettingen, Goettingen, Germany.

Background: There is a lack of agreement among measures of asthma control in children. In Central Europe, body plethysmography is additionally used for asthma monitoring. However, its value is still unclear.

Objectives: We investigated the possible additional value of body plethysmographic measures (specific resistance, residual volume-total lung capacity ratio [RV/TLC]) compared with spirometric measures forced expiratory volume in 1 second (FEV ), forced vital capacity (FVC), FEV /FVC, forced expiratory flow at 25% to 75% of forced vital capacity (FEF ), and fraction of exhaled nitric oxide (FeNO) for assessment of asthma control.

Methods: One hundred and forty-five asthmatic children aged 5 to 17 were included. All children performed measurements of FeNO, spirometry, and body plethymography. Asthma control was assessed by the asthma control test (c-ACT/ACT) and a doctor's assessment of asthma control.

Results: Investigating single lung function parameters, FEV , FEV /FVC, FEF and RV/TLC differed between controlled and partly controlled asthma. However, we found no differences between controlled and uncontrolled asthma with regard to single lung function parameters or for any parameter if investigated in a multivariable approach. This was also true if we combined obtained parameters from spirometry (comparing pathologic vs normal spirometry). Investigating the combination of body plethysmography and doctor's assessment of asthma control a significant association was found ( P = 0.02). Furthermore, combined spirometry and body plethysmography showed a significant association with both doctor's assessed asthma control ( P = 0.009) and the c-ACT/ACT ( P = 0.04). The addition of FeNO did not improve the results.

Conclusions: The combination of body plethysmography and spirometry shows best agreement with asthma control in children compared with spirometry or body plethysmography alone. Further studies are needed to find out whether additional measurements of body plethysmography improve the outcome of children in asthma monitoring.
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http://dx.doi.org/10.1002/ppul.24320DOI Listing
August 2019

Effect of bone sialoprotein coating on progression of bone formation in a femoral defect model in rats.

Eur J Trauma Emerg Surg 2020 Apr 28;46(2):277-286. Epub 2019 May 28.

Department of Orthopaedics and Traumatology, Biomatics Group, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany.

Purpose: In orthopedic and trauma surgery, calcium phosphate cement (CPC) scaffolds are widely used as substitute for autologous bone grafts. The purpose of this study was to evaluate bone formation in a femoral condyle defect model in rats after scaffold-coating with bioactive bone sialoprotein (BSP). Our hypothesis was that BSP-coating results in additional bone formation.

Methods: In 20 Wistar rats, defects of 3.0 mm diameter were drilled into the lateral femoral condyles of both legs. BSP-coated scaffolds or uncoated control scaffolds were implanted into the defects. After 4 and 8 weeks, five rats of each group were euthanized, respectively. µCT scans and histological analyses were performed. The ratio of bone volume-total volume (BV/TV) was analyzed and histological sections were evaluated.

Results: At week four, bone fraction reached 5.2 ± 1.7% in BSP-coated scaffolds and 4.5 ± 3.2% in the control (p = 0.06). While bone fraction of the BSP-group did not change much between week four and eight [week eight: 5.4 ± 3.8% (p = 0.53)], there was a tendency towards an increase in the control [week eight: 7.0 ± 2.2% (p = 0.08)]. No significant difference in bone fraction were observable between BSP-coated and uncoated scaffolds at week eight (p = 0.08).

Conclusions: A significant superiority of BSP-coated scaffolds over uncoated scaffolds could not be proven. However, BSP-coating showed a tendency towards improving bone ingrowth in the scaffolds 4 weeks after implantation. This effect was only short-lived: bone growth in the control scaffolds tended to outpace that of the BSP-group at week eight.
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http://dx.doi.org/10.1007/s00068-019-01159-5DOI Listing
April 2020