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Straub A, Utz C, Stapf M, Vollmer A, Breitenbuecher N, Kübler AC, Brands RC, Hartmann S, Lâm TT. Impact of aminopenicillin administration routes on antimicrobial effects of platelet-rich fibrin: An in-vitro investigation. J Stomatol Oral Maxillofac Surg 2024; 125:101725. [PMID: 38048907 DOI: 10.1016/j.jormas.2023.101725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
INTRODUCTION The aim of the study was to investigate the impact of different aminopenicillin administration routes on the antimicrobial effects of platelet-rich fibrin (PRF). METHODS We enrolled patients undergoing treatment with amoxicillin/clavulanic acid (AMC) orally or ampicillin/sulbactam (SAM) intravenously. AMC was applied in a single oral dose (875/125 mg), or in a double oral dose (1750/250 mg), and SAM in a dose of 2000/1000 mg. Blood was obtained one hour after the intake of AMC or 15 min after the infusion of SAM ended. Antimicrobial effects were investigated in agar diffusion tests with fresh PRF, PRF stored for 24, and PRF stored for 48 h. Agar diffusion tests were performed with Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Porphyromonas gingivalis. Inhibition zones (IZs) around a 6 mm PRF disc were measured after 24 h. RESULTS IZs for fresh PRF and the single oral dose of AMC were 0.0, 4.7, 15.2, 2.3, and 0.9 mm (E. coli, S. aureus, S. pneumoniae, H. influenzae, and P. gingivalis, respectively). For the double oral dose, these values were 0.0, 11.4, 20.0, 8.1, and 7.4 mm. IZs for SAM were 11.9, 18.2, 24.7, 20.3, and 22.1 mm. Differences between parenteral and oral application as well as between different oral doses were significant (p<0.0001, one-way ANOVA). DISCUSSION The results of our study demonstrate that oral administration is a suitable route to load PRF with these drugs. This could expand the scope of PRF application to prevent infections at the surgical site, especially in an outpatient setting in which drugs are normally applied orally.
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany.
| | - Chiara Utz
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Maximilian Stapf
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Niko Breitenbuecher
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Alexander C Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Roman C Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, Würzburg 97070, Germany
| | - Thiên-Trí Lâm
- Institute for Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Straße 2/E1, Würzburg 97080, Germany
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Vollmer A, Hartmann S, Vollmer M, Shavlokhova V, Brands RC, Kübler A, Wollborn J, Hassel F, Couillard-Despres S, Lang G, Saravi B. Multimodal artificial intelligence-based pathogenomics improves survival prediction in oral squamous cell carcinoma. Sci Rep 2024; 14:5687. [PMID: 38453964 PMCID: PMC10920832 DOI: 10.1038/s41598-024-56172-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 03/03/2024] [Indexed: 03/09/2024] Open
Abstract
In this study, we aimed to develop a novel prognostic algorithm for oral squamous cell carcinoma (OSCC) using a combination of pathogenomics and AI-based techniques. We collected comprehensive clinical, genomic, and pathology data from a cohort of OSCC patients in the TCGA dataset and used machine learning and deep learning algorithms to identify relevant features that are predictive of survival outcomes. Our analyses included 406 OSCC patients. Initial analyses involved gene expression analyses, principal component analyses, gene enrichment analyses, and feature importance analyses. These insights were foundational for subsequent model development. Furthermore, we applied five machine learning/deep learning algorithms (Random Survival Forest, Gradient Boosting Survival Analysis, Cox PH, Fast Survival SVM, and DeepSurv) for survival prediction. Our initial analyses revealed relevant gene expression variations and biological pathways, laying the groundwork for robust feature selection in model building. The results showed that the multimodal model outperformed the unimodal models across all methods, with c-index values of 0.722 for RSF, 0.633 for GBSA, 0.625 for FastSVM, 0.633 for CoxPH, and 0.515 for DeepSurv. When considering only important features, the multimodal model continued to outperform the unimodal models, with c-index values of 0.834 for RSF, 0.747 for GBSA, 0.718 for FastSVM, 0.742 for CoxPH, and 0.635 for DeepSurv. Our results demonstrate the potential of pathogenomics and AI-based techniques in improving the accuracy of prognostic prediction in OSCC, which may ultimately aid in the development of personalized treatment strategies for patients with this devastating disease.
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Affiliation(s)
- Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Franconia, Germany.
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Franconia, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, Tuebingen University Hospital, Osianderstrasse 2-8, 72076, Tuebingen, Germany
| | - Veronika Shavlokhova
- Maxillofacial Surgery University Hospital Ruppin-Brandenburg, Fehrbelliner Straße 38, 16816, Neuruppin, Germany
| | - Roman C Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Franconia, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Franconia, Germany
| | - Jakob Wollborn
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Frank Hassel
- Department of Spine Surgery, Loretto Hospital, Freiburg, Germany
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020, Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Babak Saravi
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
- Department of Spine Surgery, Loretto Hospital, Freiburg, Germany
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020, Salzburg, Austria
- Department of Orthopedics and Trauma Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Straub A, Stapf M, Brands RC, Kübler AC, Lâm TT, Vollmer A, Gubik S, Scherf-Clavel O, Hartmann S. Investigation of clindamycin concentrations in human plasma and jawbone tissue in patients with osteonecrosis of the jaw: A prospective trial. J Craniomaxillofac Surg 2024; 52:355-362. [PMID: 38368214 DOI: 10.1016/j.jcms.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/18/2023] [Accepted: 01/16/2024] [Indexed: 02/19/2024] Open
Abstract
The aim of this study was to investigate the jawbone concentration of clindamycin (CLI) in patients with an osteonecrosis of the jaw (ONJ). Patients with medication-related ONJ (MRONJ) and osteoradionecrosis (ORN) with an antibiotic treatment with CLI were included. Plasma, vital and necrotic bone samples were collected. Plasma and jawbone samples were analyzed by liquid chromatography-tandem mass spectrometry. Patients with MRONJ exhibited a mean plasma CLI concentration of 9.6 μg/mL (SD ± 3.6 μg/mL) and mean concentrations of 2.3 μg/g CLI (SD ± 1.4 μg/g) and 2.1 μg/g CLI (SD ± 2.4 μg/g) in vital and necrotic bone samples, without statistical significance (p = 0.79). In patients with ORN, mean concentration in plasma was 12.0 μg/mL (SD ± 2.6 μg/mL), in vital bone 2.1 μg/g (SD ± 1.5 μg/g), and in necrotic bone 1.7 μg/g (SD ± 1.2 μg/g). Vital and necrotic bone concentrations did not differ significantly (p = 0.88). The results demonstrate that CLI concentrations are considerably lower than in plasma, but sufficient for most bacteria present in ONJ. Within the limitations of the study, it seems that CLI is a relevant alternative to other antibiotics in the treatment of ONJ because it reaches adequate concentrations in jawbone.
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany.
| | - Maximilian Stapf
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Roman C Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Alexander C Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Thiên-Trí Lâm
- Institute for Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Str. 2/E1, 97080, Würzburg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Sebastian Gubik
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Oliver Scherf-Clavel
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany; Aalen University, Faculty of Chemistry, Beethovenstraße 1, 73430, Aalen, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
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Straub A, Stapf M, Utz C, Vollmer A, Flesch J, Kübler A, Scherf-Clavel O, Lâm TT, Hartmann S. Antimicrobial effects of clindamycin-loaded platelet-rich fibrin (PRF). Clin Oral Investig 2024; 28:144. [PMID: 38351376 PMCID: PMC10864470 DOI: 10.1007/s00784-024-05532-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/28/2024] [Indexed: 02/16/2024]
Abstract
OBJECTIVES Recent research has demonstrated that platelet-rich fibrin (PRF) is an appropriate carrier for ampicillin/sulbactam. The aim of the study was to investigate whether PRF is also a suitable bio-carrier for clindamycin (CLI). METHODS PRF membranes were produced from 36 patients receiving intravenous therapy with CLI (e.g. due to the diagnosis of an osteonecrosis of the jaw or infections). Concentrations of CLI in PRF membranes were measured with liquid chromatography-tandem mass spectrometry, and the antimicrobial effects were investigated in vitro in agar diffusion tests with fresh PRF and PRF stored for 24 h. Storage was performed in an incubator at 36 °C to simulate the in-vivo situation. RESULTS The mean concentration of CLI in plasma was 1.0 ± 0.3 μg/100 mg plasma; in resulting PRF membranes 0.7 ± 0.4 μg/100 mg PRF. Agar diffusion tests were performed with Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus mitis, Porphyromonas gingivalis, and Fusobacterium nucleatum. Mean inhibition zones, in mm, for fresh PRF were 17.3, 12.2, 18.8, 17.1, 25.8 and 18.1, 12.7, 19.2, 17.3, and 26.3 for stored PRF, respectively. CONCLUSION The results demonstrate that PRF is a suitable bio-carrier for CLI when administered systemically to patients. The concentration in PRF generated from patients after infusion of 600 mg CLI dose suffices to target clinically relevant bacteria. CLINICAL RELEVANCE Using PRF as a carrier for local antibiotic application can prevent infections in oral and maxillofacial surgery. Within the study limitations, the findings could expand the scope of PRF application by adding CLI as a new antibiotic to the spectrum of PRF therapy.
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany.
| | - Maximilian Stapf
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Chiara Utz
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Julia Flesch
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Oliver Scherf-Clavel
- Department of Pharmacy, University of München, Butenandtstraße 5, 81377, Munich, Germany
| | - Thiên-Trí Lâm
- Institute for Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Straße 2/E1, 97080, Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
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Straub A, Gubik S, Kübler A, Breitenbuecher N, Vollmer A, Renner T, Müller-Richter U, Hartmann S, Brands R. Comparison of Patient-Specific Condylar Positioning Devices and Manual Methods in Orthognathic Surgery: A Prospective Randomized Trial. J Clin Med 2024; 13:737. [PMID: 38337431 PMCID: PMC10856595 DOI: 10.3390/jcm13030737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/18/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND This study investigated whether patient-specific condylar positioning devices (CPDs) are beneficial compared to the conventional manual positioning of the condyles. METHODS In this prospective, randomized trial, patients undergoing orthognathic surgery with a bilateral sagittal split osteotomy of the mandible were included. The ascending ramus was positioned with computer-aided designed and computer-aided manufactured (CAD/CAM) patient-specific devices in the CPD group and manually in the control group. Postoperatively, cone-beam computed tomography (CBCT) was performed to align the virtually planned position with the postoperative result. RESULTS Thirty patients were enrolled in the study, with 14 randomized to the CPD group and 16 to the control group. In the CPD group, the ascending ramus differed in the postoperative CBCT scan from the virtually planned position by 0.8 mm in the left/right, 0.8 mm in the front/back, and 1.3 mm in the cranial/caudal direction. The corresponding control-group values were 1.1 mm, 1.3 mm, and 1.6 mm. CPD and controls differed significantly for the left/right movement of the rami (p = 0.04) but not for the other directions or rotations (p > 0.05). CONCLUSIONS The results demonstrate that both methods are accurate, and postoperative results matched the virtually planned position precisely. It can be assumed that the described CPDs are beneficial when a condylar position different from the preoperative is desired.
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Würzburg, Pleicherwall 2, 97070 Würzburg, Germany
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Vollmer A, Saravi B, Breitenbuecher N, Mueller-Richter U, Straub A, Šimić L, Kübler A, Vollmer M, Gubik S, Volland J, Hartmann S, Brands RC. Realizing in-house algorithm-driven free fibula flap set up within 24 hours: a pilot study evaluating accuracy with open-source tools. Front Surg 2023; 10:1321217. [PMID: 38162091 PMCID: PMC10755006 DOI: 10.3389/fsurg.2023.1321217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024] Open
Abstract
Objective This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time. Methods A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure. Results The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings. Conclusions The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.
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Affiliation(s)
- Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA,United States
| | - Niko Breitenbuecher
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Urs Mueller-Richter
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Luka Šimić
- Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, Tuebingen University Hospital, Tuebingen, Germany
| | - Sebastian Gubik
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Julian Volland
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Roman C. Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
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Vollmer A, Nagler S, Hörner M, Hartmann S, Brands RC, Breitenbücher N, Straub A, Kübler A, Vollmer M, Gubik S, Lang G, Wollborn J, Saravi B. Performance of artificial intelligence-based algorithms to predict prolonged length of stay after head and neck cancer surgery. Heliyon 2023; 9:e20752. [PMID: 37928044 PMCID: PMC10623164 DOI: 10.1016/j.heliyon.2023.e20752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023] Open
Abstract
Background Medical resource management can be improved by assessing the likelihood of prolonged length of stay (LOS) for head and neck cancer surgery patients. The objective of this study was to develop predictive models that could be used to determine whether a patient's LOS after cancer surgery falls within the normal range of the cohort. Methods We conducted a retrospective analysis of a dataset consisting of 300 consecutive patients who underwent head and neck cancer surgery between 2017 and 2022 at a single university medical center. Prolonged LOS was defined as LOS exceeding the 75th percentile of the cohort. Feature importance analysis was performed to evaluate the most important predictors for prolonged LOS. We then constructed 7 machine learning and deep learning algorithms for the prediction modeling of prolonged LOS. Results The algorithms reached accuracy values of 75.40 (radial basis function neural network) to 97.92 (Random Trees) for the training set and 64.90 (multilayer perceptron neural network) to 84.14 (Random Trees) for the testing set. The leading parameters predicting prolonged LOS were operation time, ischemia time, the graft used, the ASA score, the intensive care stay, and the pathological stages. The results revealed that patients who had a higher number of harvested lymph nodes (LN) had a lower probability of recurrence but also a greater LOS. However, patients with prolonged LOS were also at greater risk of recurrence, particularly when fewer (LN) were extracted. Further, LOS was more strongly correlated with the overall number of extracted lymph nodes than with the number of positive lymph nodes or the ratio of positive to overall extracted lymph nodes, indicating that particularly unnecessary lymph node extraction might be associated with prolonged LOS. Conclusions The results emphasize the need for a closer follow-up of patients who experience prolonged LOS. Prospective trials are warranted to validate the present results.
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Affiliation(s)
- Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Simon Nagler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Marius Hörner
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Roman C. Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Niko Breitenbücher
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital of Tübingen, 72076, Tübingen, Germany
| | - Sebastian Gubik
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070, Würzburg, Germany
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jakob Wollborn
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA
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Shavlokhova V, Vollmer A, Zouboulis CC, Vollmer M, Wollborn J, Lang G, Kübler A, Hartmann S, Stoll C, Roider E, Saravi B. Finetuning of GLIDE stable diffusion model for AI-based text-conditional image synthesis of dermoscopic images. Front Med (Lausanne) 2023; 10:1231436. [PMID: 37928464 PMCID: PMC10623307 DOI: 10.3389/fmed.2023.1231436] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023] Open
Abstract
Background The development of artificial intelligence (AI)-based algorithms and advances in medical domains rely on large datasets. A recent advancement in text-to-image generative AI is GLIDE (Guided Language to Image Diffusion for Generation and Editing). There are a number of representations available in the GLIDE model, but it has not been refined for medical applications. Methods For text-conditional image synthesis with classifier-free guidance, we have fine-tuned GLIDE using 10,015 dermoscopic images of seven diagnostic entities, including melanoma and melanocytic nevi. Photorealistic synthetic samples of each diagnostic entity were created by the algorithm. Following this, an experienced dermatologist reviewed 140 images (20 of each entity), with 10 samples originating from artificial intelligence and 10 from original images from the dataset. The dermatologist classified the provided images according to the seven diagnostic entities. Additionally, the dermatologist was asked to indicate whether or not a particular image was created by AI. Further, we trained a deep learning model to compare the diagnostic results of dermatologist versus machine for entity classification. Results The results indicate that the generated images possess varying degrees of quality and realism, with melanocytic nevi and melanoma having higher similarity to real images than other classes. The integration of synthetic images improved the classification performance of the model, resulting in higher accuracy and precision. The AI assessment showed superior classification performance compared to dermatologist. Conclusion Overall, the results highlight the potential of synthetic images for training and improving AI models in dermatology to overcome data scarcity.
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Affiliation(s)
- Veronika Shavlokhova
- Maxillofacial Surgery University Hospital Ruppin-Fehrbelliner Straße Neuruppin, Neuruppin, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Christos C. Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Staedtisches Klinikum Dessau, Medical School Theodor Fontane and Faculty of Health Sciences Brandenburg, Dessau, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, Tuebingen University Hospital, Tuebingen, Germany
| | - Jakob Wollborn
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Christian Stoll
- Maxillofacial Surgery University Hospital Ruppin-Fehrbelliner Straße Neuruppin, Neuruppin, Germany
| | - Elisabeth Roider
- Department of Dermatology, University Hospital of Basel, Basel, Switzerland
| | - Babak Saravi
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
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9
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Straub A, Utz C, Stapf M, Vollmer A, Kasper S, Kübler AC, Brands RC, Hartmann S, Lâm TT. Investigation of three common centrifugation protocols for platelet-rich fibrin (PRF) as a bio-carrier for ampicillin/sulbactam: a prospective trial. Clin Oral Investig 2023; 27:5991-5998. [PMID: 37603167 PMCID: PMC10560174 DOI: 10.1007/s00784-023-05212-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 08/14/2023] [Indexed: 08/22/2023]
Abstract
OBJECTIVES Different platelet-rich fibrin (PRF) protocols exist and are known to differ in resulting mechanical and bioactive properties. Centrifugation parameters may also influence drug release, in particular antibiotics, when using PRF as a bio-carrier. We thus evaluated three common protocols regarding effects on the bio-carrier properties. MATERIALS AND METHODS In a prospective trial comprising 33 patients, we compared different protocols for PRF as a bio-carrier for ampicillin/sulbactam (SAM). Blood samples were taken shortly after a single dose of ampicillin/sulbactam (2 g/1 g) was administered to patients intravenously. PRF was obtained by centrifugation and three protocols were used: protocol A (1300 rpm, 8 min, RCF-max = 208 g), B (2300 rpm, 12 min, RCF-max = 652 g), and C (1500 rpm, 14 min, RCF-max = 276 g). The antibacterial activity of PRF was investigated against five oral species in vitro, based on agar diffusion methodology. RESULTS The study demonstrates that a single dose of SAM is sufficient to reach high concentrations in PRF in all protocols (150 µg/ml), which is comparable to the plasma SAM concentration. Antibacterial activity was inferred from the diameter of inhibition zones seen in agar diffusion tests using PRF discs. Protocol B resulted in the largest inhibition zones. One-way ANOVA revealed statistically improved results for protocol B for some bacteria. CONCLUSIONS The study provides valuable data on PRF antibiotic enrichment, notably SAM. A single dose of SAM is sufficient to reach clinically relevant concentrations in PRF. CLINICAL RELEVANCE These findings potentially extend the application of PRF, for example in patients with osteonecrosis of the jaw or in oral surgery (e.g., stick bone).
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany.
| | - Chiara Utz
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Maximilian Stapf
- Institute for Pharmacy and Food Chemistry of the University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Sylvia Kasper
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Alexander C Kübler
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Roman C Brands
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery of the University Hospital Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
| | - Thiên-Trí Lâm
- Institute for Hygiene and Microbiology of the University of Würzburg, Josef-Schneider-Street 2/E1, 97080, Würzburg, Germany
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10
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Fessmann N, Vollmer A, Singer J, Mecner M. [Biplanar clavicle extension osteotomy : A case report of an extension osteotomy due to shortening of a healed clavicle fracture with sagittal split technique and corticocancellous graft]. Unfallchirurgie (Heidelb) 2023; 126:504-507. [PMID: 35725932 DOI: 10.1007/s00113-022-01199-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/20/2022] [Indexed: 06/01/2023]
Abstract
Clavicle fractures healed in shortening or malposition are extremely rare, especially in adolescence. In extreme cases, they can result in massive pain and limitation of movement. A causal therapeutic approach is lengthening osteotomy using the sagittal split technique with tricortical iliac crest interposition. In the context of the case study of a young patient, the procedure, operation as well as documentation of the postoperative results are reported.
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Affiliation(s)
- Nina Fessmann
- Unfallchirugie und Orthopädie, Rems-Murr-Klinikum Winnenden, Am Jakobswegs 1, 71364, Winnenden, Deutschland.
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Würzburg, 97070, Würzburg, Deutschland
| | - Joachim Singer
- Unfallchirugie und Orthopädie, Rems-Murr-Klinikum Winnenden, Am Jakobswegs 1, 71364, Winnenden, Deutschland
| | - Michael Mecner
- Unfallchirugie und Orthopädie, Rems-Murr-Klinikum Winnenden, Am Jakobswegs 1, 71364, Winnenden, Deutschland
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11
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Vollmer A, Vollmer M, Lang G, Straub A, Shavlokhova V, Kübler A, Gubik S, Brands R, Hartmann S, Saravi B. Associations between Periodontitis and COPD: An Artificial Intelligence-Based Analysis of NHANES III. J Clin Med 2022; 11:jcm11237210. [PMID: 36498784 PMCID: PMC9737076 DOI: 10.3390/jcm11237210] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
A number of cross-sectional epidemiological studies suggest that poor oral health is associated with respiratory diseases. However, the number of cases within the studies was limited, and the studies had different measurement conditions. By analyzing data from the National Health and Nutrition Examination Survey III (NHANES III), this study aimed to investigate possible associations between chronic obstructive pulmonary disease (COPD) and periodontitis in the general population. COPD was diagnosed in cases where FEV (1)/FVC ratio was below 70% (non-COPD versus COPD; binary classification task). We used unsupervised learning utilizing k-means clustering to identify clusters in the data. COPD classes were predicted with logistic regression, a random forest classifier, a stochastic gradient descent (SGD) classifier, k-nearest neighbors, a decision tree classifier, Gaussian naive Bayes (GaussianNB), support vector machines (SVM), a custom-made convolutional neural network (CNN), a multilayer perceptron artificial neural network (MLP), and a radial basis function neural network (RBNN) in Python. We calculated the accuracy of the prediction and the area under the curve (AUC). The most important predictors were determined using feature importance analysis. Results: Overall, 15,868 participants and 19 feature variables were included. Based on k-means clustering, the data were separated into two clusters that identified two risk characteristic groups of patients. The algorithms reached AUCs between 0.608 (DTC) and 0.953% (CNN) for the classification of COPD classes. Feature importance analysis of deep learning algorithms indicated that age and mean attachment loss were the most important features in predicting COPD. Conclusions: Data analysis of a large population showed that machine learning and deep learning algorithms could predict COPD cases based on demographics and oral health feature variables. This study indicates that periodontitis might be an important predictor of COPD. Further prospective studies examining the association between periodontitis and COPD are warranted to validate the present results.
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Affiliation(s)
- Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
- Correspondence:
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, Tuebingen University Hospital, Osianderstrasse 2-8, 72076 Tuebingen, Germany
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
| | - Veronika Shavlokhova
- Division of Medicine, Department of Oral and Maxillofacial Surgery, University Hospital Ruppin-Brandenburg, Brandenburg Medical School, Fehrbelliner Straße 38, 16816 Neuruppin, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
| | - Sebastian Gubik
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
| | - Roman Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital of Würzburg, 97070 Würzburg, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
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12
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Straub A, Stapf M, Fischer M, Vollmer A, Linz C, Lâm TT, Kübler A, Brands RC, Scherf-Clavel O, Hartmann S. Bone Concentration of Ampicillin/Sulbactam: A Pilot Study in Patients with Osteonecrosis of the Jaw. Int J Environ Res Public Health 2022; 19:14917. [PMID: 36429636 PMCID: PMC9690242 DOI: 10.3390/ijerph192214917] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Osteonecrosis of the jaw (ONJ) occurs typically after irradiation of the head and neck area or after the intake of antiresorptive agents. Both interventions can lead to compromised bone perfusion and can ultimately result in infection and necrosis. Treatment usually consists of surgical necrosectomy and prolonged antibiotic therapy, usually through beta-lactams such as ampicillin/sulbactam. The poor blood supply in particular raises the question as to whether this form of antibiosis can achieve sufficient concentrations in the bone. Therefore, we investigated the antibiotic concentration in plasma and bone samples in a prospective study. Bone samples were collected from the necrosis core and in the vital surrounding bone. The measured concentrations in plasma for ampicillin and sulbactam were 126.3 ± 77.6 and 60.2 ± 35.0 µg/mL, respectively. In vital bone and necrotic bone samples, the ampicillin/sulbactam concentrations were 6.3 ± 7.8/1.8 ± 2.0 µg/g and 4.9 ± 7.0/1.7 ± 1.7 µg/g, respectively. These concentrations are substantially lower than described in the literature. However, the concentration seems sufficient to kill most bacteria, such as Streptococci and Staphylococci, which are mostly present in the biofilm of ONJ. We, therefore, conclude that intravenous administration of ampicillin/sulbactam remains a valuable treatment in the therapy of ONJ. Nevertheless, increasing resistance of Escherichia coli towards beta-lactam antibiotics have been reported and should be considered.
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Affiliation(s)
- Anton Straub
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Maximilian Stapf
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Markus Fischer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Christian Linz
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Thiên-Trí Lâm
- Institute for Hygiene and Microbiology, University of Wuerzburg, Josef-Schneider-Str. 2/E1, 97080 Wuerzburg, Germany
| | - Alexander Kübler
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Roman C. Brands
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
| | - Oliver Scherf-Clavel
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany
| | - Stefan Hartmann
- Department of Oral and Maxillofacial Plastic Surgery, University Hospital Wuerzburg, Pleicherwall 2, 97070 Wuerzburg, Germany
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13
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Shavlokhova V, Vollmer M, Gholam P, Saravi B, Vollmer A, Hoffmann J, Engel M, Freudlsperger C. Deep Learning on Basal Cell Carcinoma In Vivo Reflectance Confocal Microscopy Data. J Pers Med 2022; 12:jpm12091471. [PMID: 36143256 PMCID: PMC9506260 DOI: 10.3390/jpm12091471] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Extended skin malignancies of the head and neck region are among the most common cancer types and are associated with numerous diagnostic and therapeutical problems. The radical resection of skin cancer in the facial area often leads to severe functional and aesthetic impairment, and precise margin assessments can avoid the extensive safety margins. On the other hand, the complete removal of the cancer is essential to minimize the risk of recurrence. Reliable intraoperative assessments of the wound margins could overcome this discrepancy between minimal invasiveness and safety distance in the head and neck region. With the help of reflectance confocal laser microscopy (RCM), cells can be visualized in high resolution intraoperatively. The combination with deep learning and automated algorithms allows an investigator independent and objective interpretation of specific confocal imaging data. Therefore, we aimed to apply a deep learning algorithm to detect malignant areas in images obtained via in vivo confocal microscopy. We investigated basal cell carcinoma (BCC), as one of the most common entities with well-described in vivo RCM diagnostic criteria, within a preliminary feasibility study. Patients and Methods: We included 62 patients with histologically confirmed BCC in the head and neck region. All patients underwent in vivo confocal laser microscope scanning. Approximately 382 images with BCC structures could be obtained, annotated, and proceeded for further deep learning model training. Results: A sensitivity of 46% and a specificity of 85% in detecting BCC regions could be achieved using a convolutional neural network model (“MobileNet”). Conclusion: The preliminary results reveal the potential and limitations of the automated detection of BCC with in vivo RCM. Further studies with a larger number of cases are required to obtain better predictability.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Patrick Gholam
- Department of Dermatology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre—Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
- Correspondence:
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Jürgen Hoffmann
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Michael Engel
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany
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14
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Tesfai AS, Vollmer A, Özen AC, Braig M, Semper-Hogg W, Altenburger MJ, Ludwig U, Bock M. Inductively Coupled Intraoral Flexible Coil for Increased Visibility of Dental Root Canals in Magnetic Resonance Imaging. Invest Radiol 2022; 57:163-170. [PMID: 34510099 DOI: 10.1097/rli.0000000000000826] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Accurate visualization of dental root canals is vital for the correct diagnosis and subsequent treatment. This work assesses the improvement of a dedicated new coil for dental magnetic resonance imaging (MRI) in comparison to conventional ones in terms of signal-to-noise ratio (SNR) and visibility. MATERIALS AND METHODS A newly developed intraoral flexible coil was used to display dental roots with MRI, and it provides improved sensitivity with a loop design and size adjusted to a single tooth anatomy. Ex vivo and in vivo measurements were performed on a 3 T clinical MR system, and results were compared with conventional head and surface coil images. Additional comparison was performed with a modified fast spin echo sequence and a constructive interference in steady-state sequence. RESULTS Ex vivo, an SNR gain of 6.3 could be achieved with the intraoral flexible coil setup, and higher visibility down to 200 μm was possible, whereas the external loop coil is limited to 400 μm. In vivo measurements in a volunteer resulted in an SNR gain of up to 4.5 with an improved delineation of the root canals, especially for the branch tissue splitting of the mesial root canal into mesial-buccal and mesial-lingual. CONCLUSIONS In summary, we showed the feasibility of implementing a wireless coil approach with readily available dental practice materials for sealing and placement. Highly improved MRI scans can be acquired within clinically feasible scan times, and this might provide additional medical findings to supplement available x-ray images.
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Affiliation(s)
| | - Andreas Vollmer
- Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg
| | | | | | - Wiebke Semper-Hogg
- Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg
| | - Markus Jörg Altenburger
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ute Ludwig
- From the Department of Radiology, Medical Physics
| | - Michael Bock
- From the Department of Radiology, Medical Physics
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15
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Shavlokhova V, Flechtenmacher C, Sandhu S, Vollmer M, Vollmer A, Saravi B, Engel M, Ristow O, Hoffmann J, Freudlsperger C. Ex vivo fluorescent confocal microscopy images of oral mucosa: Tissue atlas and evaluation of the learning curve. J Biophotonics 2022; 15:e202100225. [PMID: 34796650 DOI: 10.1002/jbio.202100225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/13/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Ex vivo fluorescence confocal microscopy (FCM) is a developing tool providing rapid digital imaging of fresh tissue utilizing high-resolution optical sectioning that highly corresponds with conventional hmatoxylin and eosin (H&E)-stained slides. A very little data on oral mucosa lesions exist currently. The present work aimed to create an image atlas of benign and malignant oral tissues and compare them to the corresponding histopathology. Furthermore, we aimed to evaluate the learning curve for confocal image interpretation. From 50 samples obtained from the oral mucosa, including oral squamous cell carcinoma (OSCC), dysplasia, and healthy oral tissue, ex vivo FCM images and corresponding H&E slides were created and collected into a tissue atlas. Additionally, two experts were asked to analyze the images to assess the learning curve. Ex vivo FCM images revealed high comparability with histopathological images. Tissues including OSCC, dysplasia, and normal oral mucosa were implemented in the image atlas to provide the diagnostic fundament for pathologists and surgeons; the learning curve was short. Future studies on this topic will be advantageous for the development of artificial intelligence-based diagnostic approaches. The current work provides a novel set of data that are structured as an atlas of common pathologies of the mucosa to enhance the existing knowledge and material on confocal images.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | | | - Sameena Sandhu
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Michael Engel
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | - Oliver Ristow
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
| | - Jürgen Hoffmann
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
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16
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Shavlokhova V, Vollmer M, Vollmer A, Gholam P, Saravi B, Hoffmann J, Engel M, Elsner J, Neumeier F, Freudlsperger C. In vivo reflectance confocal microscopy of wounds: feasibility of intraoperative basal cell carcinoma margin assessment. Ann Transl Med 2021; 9:1716. [PMID: 35071410 PMCID: PMC8743714 DOI: 10.21037/atm-21-3462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/22/2021] [Indexed: 11/23/2022]
Abstract
Background In vivo reflectance confocal microscopy (RCM) is well established in non-melanoma skin cancer detection and screening. However, there is no sufficient validation regarding intraoperatively obtained images of wound margins. A reliable and fast resection margin detection is of high clinical relevance. Hence, we aimed to investigate feasibility and validity of in vivo RCM imaging for wound margins assessment compared with standard skin surface imaging and the gold standard histopathology. Methods A surgical incision through the center of a large basal cell carcinoma (BCC) affected area in the head and face region was performed. After removing half of the tumor, the wound margins of the remaining half as well as the corresponding skin surface were scanned with an in vivo RCM. A total of 50 wound margin images with BCC, 50 images of BCC-free margins and the corresponding skin surface images from 50 patients were compared with each other and with histopathological findings. Presence of confocal diagnostic criteria for BCC in images was analyzed. Results An overall sensitivity and specificity in detection of BCC in wound margins was 88.5%, and 91.7% compared to skin surface imaging and 97.8% and 90.7%, respectively, compared to histopathology. We identified all known confocal patterns of healthy skin and BCC in wound margin scans: damage of the epidermal layer above the lesion and cellular pleomorphism, elongated and monomorphic basaloid nuclei, nuclear polarization, an increased number of dilated blood vessels with high leukocyte traffic, inflammatory cells. Conclusions The accuracy of in vivo RCM imaging of wound margins is comparable with a standard skin surface imaging. The intraoperative detection of BCC areas in wound margins is as precise as the standard skin imaging and may be supportive for surgical interventions.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Patrick Gholam
- Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Jürgen Hoffmann
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Michael Engel
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | | | | | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
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17
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Shavlokhova V, Sandhu S, Flechtenmacher C, Koveshazi I, Neumeier F, Padrón-Laso V, Jonke Ž, Saravi B, Vollmer M, Vollmer A, Hoffmann J, Engel M, Ristow O, Freudlsperger C. Deep Learning on Oral Squamous Cell Carcinoma Ex Vivo Fluorescent Confocal Microscopy Data: A Feasibility Study. J Clin Med 2021; 10:5326. [PMID: 34830608 PMCID: PMC8618824 DOI: 10.3390/jcm10225326] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/11/2021] [Accepted: 11/13/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Ex vivo fluorescent confocal microscopy (FCM) is a novel and effective method for a fast-automatized histological tissue examination. In contrast, conventional diagnostic methods are primarily based on the skills of the histopathologist. In this study, we investigated the potential of convolutional neural networks (CNNs) for automatized classification of oral squamous cell carcinoma via ex vivo FCM imaging for the first time. MATERIAL AND METHODS Tissue samples from 20 patients were collected, scanned with an ex vivo confocal microscope immediately after resection, and investigated histopathologically. A CNN architecture (MobileNet) was trained and tested for accuracy. RESULTS The model achieved a sensitivity of 0.47 and specificity of 0.96 in the automated classification of cancerous tissue in our study. CONCLUSION In this preliminary work, we trained a CNN model on a limited number of ex vivo FCM images and obtained promising results in the automated classification of cancerous tissue. Further studies using large sample sizes are warranted to introduce this technology into clinics.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Sameena Sandhu
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | | | | | | | | | - Žan Jonke
- Munich Innovation Labs GmbH, 80336 Munich, Germany; (V.P.-L.); (Ž.J.)
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany;
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Jürgen Hoffmann
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Michael Engel
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Oliver Ristow
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (M.E.); (O.R.); (C.F.)
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18
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Shavlokhova V, Goeppert B, Gaida MM, Saravi B, Weichel F, Vollmer A, Vollmer M, Freudlsperger C, Mertens C, Hoffmann J. Mandibular Brown Tumor as a Result of Secondary Hyperparathyroidism: A Case Report with 5 Years Follow-Up and Review of the Literature. Int J Environ Res Public Health 2021; 18:ijerph18147370. [PMID: 34299820 PMCID: PMC8304219 DOI: 10.3390/ijerph18147370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/01/2021] [Accepted: 07/05/2021] [Indexed: 12/02/2022]
Abstract
Background: Brown tumor is a rare skeletal manifestation of secondary hyperparathyroidism. Although diagnosis of the disease is increasingly seen in early stages due to improved screening techniques, some patients still present in a progressed disease stage. The treatment depends on tumor mass and varies from a conservative approach with supportive parathyroidectomy to extensive surgical resection with subsequent reconstruction. Case presentation: We report a case of extensive mandibular brown tumor in a patient with a history of systemic lupus erythematosus, chronic kidney disease, and secondary hyperparathyroidism. Following radical resection of the affected bone, reconstruction could be successfully performed using a free flap. Conclusions: There were no signs of recurrence during five years of close follow-up. Increased awareness and multidisciplinary follow-ups could allow early diagnosis and prevent the need for radical therapeutical approaches.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
- Correspondence:
| | - Benjamin Goeppert
- Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany; (B.G.); (M.M.G.)
| | - Matthias M. Gaida
- Institute of Pathology, University Hospital Heidelberg, 69120 Heidelberg, Germany; (B.G.); (M.M.G.)
- Institute of Pathology, University Medical Center Mainz, Johannes Gutenberg-Universität Mainz, 55131 Mainz, Germany
| | - Babak Saravi
- Department of Orthopedics and Trauma Surgery, Medical Centre-Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany;
| | - Frederic Weichel
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
| | - Andreas Vollmer
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
| | - Michael Vollmer
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
| | - Christian Freudlsperger
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
| | - Christian Mertens
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
| | - Jürgen Hoffmann
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (F.W.); (A.V.); (M.V.); (C.F.); (C.M.); (J.H.)
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19
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Shavlokhova V, Flechtenmacher C, Sandhu S, Vollmer M, Vollmer A, Pilz M, Hoffmann J, Ristow O, Engel M, Freudlsperger C. Feasibility and Implementation of Ex Vivo Fluorescence Confocal Microscopy for Diagnosis of Oral Leukoplakia: Preliminary Study. Diagnostics (Basel) 2021; 11:diagnostics11060951. [PMID: 34073373 PMCID: PMC8228631 DOI: 10.3390/diagnostics11060951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 11/23/2022] Open
Abstract
Background: Oral leukoplakia is a potentially malignant lesion with a clinical impression similar to different benign and malignant lesions. Ex vivo fluorescence confocal microscopy is a developing approach for a rapid “chairside” detection of oral lesions with a cellular-level resolution. A possible application of interest is a quick differentiation of benign oral pathology from normal or cancerous tissue. The aim of this study was to analyze the sensitivity and specificity of ex vivo fluorescence confocal microscopy (FCM) for detecting oral leukoplakia and to compare confocal images with gold-standard histopathology. Methods: Imaging of 106 submosaics of 27 oral lesions was performed using an ex vivo fluorescence confocal microscope immediately after excision. Every confocal image was qualitatively assessed for presence or absence of leukoplakia by an expert reader of confocal images. The results were compared to conventional histopathology with H&E staining. Results: Leukoplakia was detected with an overall sensitivity of 96.3%, specificity of 92.3%, positive predictive value of 93%, and negative predictive value of 96%. Conclusion: The results demonstrate the potential of ex vivo confocal microscopy in fresh tissue for rapid real-time assessment of oral pathologies.
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Affiliation(s)
- Veronika Shavlokhova
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
- Correspondence:
| | | | - Sameena Sandhu
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Michael Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Maximilian Pilz
- Department of Medical Biometry at the Institute of Medical Biometry and Informatics, University Hospital Heidelberg, 69120 Heidelberg, Germany;
| | - Jürgen Hoffmann
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Oliver Ristow
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Michael Engel
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, 69120 Heidelberg, Germany; (S.S.); (M.V.); (A.V.); (J.H.); (O.R.); (M.E.); (C.F.)
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20
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Saravi B, Vollmer A, Hartmann M, Lang G, Kohal RJ, Boeker M, Patzelt SBM. Clinical Performance of CAD/CAM All-Ceramic Tooth-Supported Fixed Dental Prostheses: A Systematic Review and Meta-Analysis. Materials (Basel) 2021; 14:ma14102672. [PMID: 34065202 PMCID: PMC8161295 DOI: 10.3390/ma14102672] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 12/29/2022]
Abstract
Although CAD/CAM ceramics present a promising alternative to metal-ceramic fixed dental prostheses, little is known about their mid- and long-term clinical performance. This systematic review aims to estimate the survival and success rates and describes the underlying complication characteristics for CAD/CAM tooth-supported zirconia- and lithium disilicate-based fixed dental prostheses (FDPs). We systematically searched MEDLINE and Web of Science to find relevant prospective studies with a follow-up of at least one year. We estimated pooled 1-, 5-, and 10-year survival and success rates by combining the collected data in a Poisson regression model. Descriptive statistics were conducted to evaluate the distribution of failures and complications in the included studies. Risk of bias for the included studies was assessed with an adapted checklist for single-arm trials. Pooled estimated 1-, 5-, and 10-year survival rates ranged from 93.80% to 94.66%, 89.67% to 91.1%, and 79.33% to 82.20%, respectively. The corresponding success rates excluding failures, but including any other types of intervention were 94.53% to 96.77%, 90.89% to 94.62%, and 81.78% to 89.25%. Secondary caries was the most frequent cause of failure, followed by chipping of the veneering. The most common cause of complication excluding failures but requiring intervention was chipping of the veneering. Risk of bias was generally acceptable for the included studies, with seven studies associated with low risk of bias, eight studies with a moderate risk of bias, and three studies with serious risk of bias. The current meta-analysis on CAD/CAM-supported FDPs revealed satisfying survival and success rates for up to 10 years of exposure. More prospective studies focusing on long-term performance are needed to strengthen the evidence currently available in the literature.
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Affiliation(s)
- Babak Saravi
- Medical Center—University of Freiburg, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, University of Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany;
- Correspondence:
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany;
| | - Maja Hartmann
- Private Practice, Kantstraße 10, 60316 Frankfurt am Main, Germany;
| | - Gernot Lang
- Medical Center—University of Freiburg, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, University of Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany;
| | - Ralf-Joachim Kohal
- Medical Center—University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany; (R.-J.K.); (S.B.M.P.)
| | - Martin Boeker
- Medical Center—University of Freiburg, Institute of Medical Biometry and Medical Statistics, Faculty of Medicine, University of Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany;
| | - Sebastian B. M. Patzelt
- Medical Center—University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany; (R.-J.K.); (S.B.M.P.)
- Private Practice, Am Dorfplatz 3, 78658 Zimmern o.R., Germany
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21
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Saravi B, Lang G, Steger R, Vollmer A, Zwingmann J. Corrective Osteotomy of Upper Extremity Malunions Using Three-Dimensional Planning and Patient-Specific Surgical Guides: Recent Advances and Perspectives. Front Surg 2021; 8:615026. [PMID: 33614702 PMCID: PMC7887308 DOI: 10.3389/fsurg.2021.615026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/13/2021] [Indexed: 11/23/2022] Open
Abstract
Malunions of the upper extremity can result in severe functional problems and increase the risk of osteoarthritis. The surgical reconstruction of complex malunions can be technically challenging. Recent advances in computer-assisted orthopedic surgery provide an innovative solution for complex three-dimensional (3-D) reconstructions. This study aims to evaluate the clinical applicability of 3-D computer-assisted planning and surgery for upper extremity malunions. Hence, we provide a summary of evidence on this topic and highlight recent advances in this field. Further, we provide a practical implementation of this therapeutic approach based on three cases of malunited forearm fractures treated with corrective osteotomy using preoperative three-dimensional simulation and patient-specific surgical guides. All three cases, one female (56 years old) and two males (18 and 26 years old), had painful restrictions in range of motion (ROM) due to forearm malunions and took part in clinical and radiologic assessments. Postoperative evaluation of patient outcomes showed a substantial increase in range of motion, reduction of preoperatively reported pain, and an overall improvement of patients' satisfaction. The therapeutic approach used in these cases resulted in an excellent anatomical and functional reconstruction and was assessed as precise, safe, and reliable. Based on current evidence and our results, the 3-D preoperative planning technique could be the new gold standard in the treatment of complex upper extremity malunions in the future.
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Affiliation(s)
- Babak Saravi
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Centre, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Centre, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Rebecca Steger
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Centre, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Andreas Vollmer
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Medical Centre, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Jörn Zwingmann
- Department of Orthopedics and Trauma Surgery, St. Elisabeth Hospital Ravensburg, Ravensburg, Germany
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22
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Vollmer A, Al-Ahmad A, Argyropoulou A, Thurnheer T, Hellwig E, Attin T, Vach K, Wittmer A, Ferguson K, Skaltsounis AL, Karygianni L. Antimicrobial Photoinactivation Using Visible Light Plus Water-Filtered Infrared-A (VIS + wIRA) and Hypericum Perforatum Modifies In Situ Oral Biofilms. Sci Rep 2019; 9:20325. [PMID: 31889168 PMCID: PMC6937260 DOI: 10.1038/s41598-019-56925-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/19/2019] [Indexed: 12/24/2022] Open
Abstract
Due to increasing antibiotic resistance, the application of antimicrobial photodynamic therapy (aPDT) is gaining increasing popularity in dentistry. The aim of this study was to investigate the antimicrobial effects of aPDT using visible light (VIS) and water-filtered infrared-A (wIRA) in combination with a Hypericum perforatum extract on in situ oral biofilms. The chemical composition of H. perforatum extract was analyzed using ultra-high-performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HRMS). To obtain initial and mature oral biofilms in situ, intraoral devices with fixed bovine enamel slabs (BES) were carried by six healthy volunteers for two hours and three days, respectively. The ex situ exposure of biofilms to VIS + wIRA (200 mWcm-2) and H. perforatum (32 mg ml-1, non-rinsed or rinsed prior to aPDT after 2-min preincubation) lasted for five minutes. Biofilm treatment with 0.2% chlorhexidine gluconate solution (CHX) served as a positive control, while untreated biofilms served as a negative control. The colony-forming units (CFU) of the aPDT-treated biofilms were quantified, and the surviving microorganisms were identified using MALDI-TOF biochemical tests as well as 16 S rDNA-sequencing. We could show that the H. perforatum extract had significant photoactivation potential at a concentration of 32 mg ml-1. When aPDT was carried out in the presence of H. perforatum, all biofilms (100%) were completely eradicated (p = 0.0001). When H. perforatum was rinsed off prior to aPDT, more than 92% of the initial viable bacterial count and 13% of the mature oral biofilm were killed. Overall, the microbial composition in initial and mature biofilms was substantially altered after aPDT, inducing a shift in the synthesis of the microbial community. In conclusion, H. perforatum-mediated aPDT using VIS + wIRA interferes with oral biofilms, resulting in their elimination or the substantial alteration of microbial diversity and richness. The present results support the evaluation of H. perforatum-mediated aPDT for the adjunctive treatment of biofilm-associated oral diseases.
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Affiliation(s)
- Andreas Vollmer
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Ali Al-Ahmad
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Aikaterini Argyropoulou
- Department of Pharmacognosy and Chemistry of Natural Products, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Thomas Thurnheer
- Clinic for Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Elmar Hellwig
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany
| | - Thomas Attin
- Clinic for Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Kirstin Vach
- Institute for Medical Biometry and Statistics, Center for Medical Biometry and Medical Informatics, Albert-Ludwigs-University, Freiburg, Germany
| | - Annette Wittmer
- Institute of Medical Microbiology and Hygiene, Albert-Ludwigs-University, Freiburg, Germany
| | - Kerry Ferguson
- Botanical Innovation, Unit 2, 390 Clergate Road, Orange, NSW, 2800, Australia
| | - Alexios Leandros Skaltsounis
- Department of Pharmacognosy and Chemistry of Natural Products, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Lamprini Karygianni
- Clinic for Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
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23
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Hofmann OT, Glowatzki H, Bürker C, Rangger GM, Bröker B, Niederhausen J, Hosokai T, Salzmann I, Blum RP, Rieger R, Vollmer A, Rajput P, Gerlach A, Müllen K, Schreiber F, Zojer E, Koch N, Duhm S. Orientation-Dependent Work-Function Modification Using Substituted Pyrene-Based Acceptors. J Phys Chem C Nanomater Interfaces 2017; 121:24657-24668. [PMID: 29152034 PMCID: PMC5682610 DOI: 10.1021/acs.jpcc.7b08451] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/10/2017] [Indexed: 05/17/2023]
Abstract
The adsorption of molecular acceptors is a viable method for tuning the work function of metal electrodes. This, in turn, enables adjusting charge injection barriers between the electrode and organic semiconductors. Here, we demonstrate the potential of pyrene-tetraone (PyT) and its derivatives dibromopyrene-tetraone (Br-PyT) and dinitropyrene-tetraone (NO2-PyT) for modifying the electronic properties of Au(111) and Ag(111) surfaces. The systems are investigated by complementary theoretical and experimental approaches, including photoelectron spectroscopy, the X-ray standing wave technique, and density functional theory simulations. For some of the investigated interfaces the trends expected for Fermi-level pinning are observed, i.e., an increase of the metal work function along with increasing molecular electron affinity and the same work function for Au and Ag with monolayer acceptor coverage. Substantial deviations are, however, found for Br-PyT/Ag(111) and NO2-PyT/Ag(111), where in the latter case an adsorption-induced work function increase of as much as 1.6 eV is observed. This behavior is explained as arising from a face-on to edge-on reorientation of molecules in the monolayer. Our calculations show that for an edge-on orientation much larger work-function changes can be expected despite the prevalence of Fermi-level pinning. This is primarily ascribed to a change of the electron affinity of the adsorbate layer that results from a change of the molecular orientation. This work provides a comprehensive understanding of how changing the molecular electron affinity as well as the adsorbate structure impacts the electronic properties of electrodes.
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Affiliation(s)
- O. T. Hofmann
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
- E-mail:
| | - H. Glowatzki
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - C. Bürker
- Institut
für Angewandte Physik, Universität
Tübingen, Auf
der Morgenstelle 10, Tübingen 72076, Germany
| | - G. M. Rangger
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
| | - B. Bröker
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Newtonstraße 15, 12389 Berlin, Germany
| | - J. Niederhausen
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - T. Hosokai
- National
Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - I. Salzmann
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Newtonstraße 15, 12389 Berlin, Germany
- The
Institute of Solid State Physics, The University
of Tokyo, Kashiwanoha
5-1-5, Kashiwa, Chiba 277-8581, Japan
| | - R.-P. Blum
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Newtonstraße 15, 12389 Berlin, Germany
| | - R. Rieger
- Max Planck
Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | - A. Vollmer
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - P. Rajput
- Atomic
& Molecular Physics Division, Bhabha
Atomic Research Centre, Trombay, Mumbai 400085, India
| | - A. Gerlach
- Institut
für Angewandte Physik, Universität
Tübingen, Auf
der Morgenstelle 10, Tübingen 72076, Germany
| | - K. Müllen
- Max Planck
Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
- Institute
of Physical Chemistry, Johannes Gutenberg
University Mainz, Duesbergweg
10-14, Mainz, Germany
| | - F. Schreiber
- Institut
für Angewandte Physik, Universität
Tübingen, Auf
der Morgenstelle 10, Tübingen 72076, Germany
| | - E. Zojer
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
| | - N. Koch
- Helmholtz-Zentrum
Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
- Institut
für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Newtonstraße 15, 12389 Berlin, Germany
- Jiangsu
Key Laboratory for Carbon-Based Functional Materials & Devices
and Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou 215123, P.R. China
| | - S. Duhm
- Jiangsu
Key Laboratory for Carbon-Based Functional Materials & Devices
and Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou 215123, P.R. China
- E-mail:
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24
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Abstract
Spaltprodukte wurden in Targets verschiedener Ordnungszahlen abgebremst. Die dabei auftretende Ionisation innerer Elektronenschalen wurde mit Hilfe der charakteristischen RÖNTGEN-Strahlung als Funktion der Energie der Spaltprodukte, der Masse der Spaltprodukte und der Ordnungszahl der Target-Atome gemessen. Ferner wurde eine Abhängigkeit der Energie der L-Strahlung der Spaltprodukte von der Ordnungszahl der Target-Atome gefunden.
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Affiliation(s)
- P. Armbruster
- Laboratorium für Technische Physik der Technischen Hochschule München
| | - E. Röckl
- Laboratorium für Technische Physik der Technischen Hochschule München
| | - H. J. Specht
- Laboratorium für Technische Physik der Technischen Hochschule München
| | - A. Vollmer
- Laboratorium für Technische Physik der Technischen Hochschule München
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25
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Möst T, Eitner S, Neukam FW, Wichmann M, Nonhof J, Kreuzwieser T, Vollmer A, Schlegel KA. i.lect, a pre-graduate education model of implantology. Eur J Dent Educ 2013; 17:106-113. [PMID: 23574188 DOI: 10.1111/eje.12018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/19/2012] [Indexed: 06/02/2023]
Abstract
OBJECTIVE In 2008, a consensus meeting of the Association for Dental Education in Europe stated that dental implant treatment represents a popular treatment alternative and, therefore, it should be an integral part of dental student pre-graduate education. In 2009, the Friedrich-Alexander University, Erlangen-Nuremberg implemented a voluntary, structured, education program for pre-graduate dental students, called 'i.lect'. The present study evaluated the effectiveness of the i.lect program. METHODS Concurrent to the dental curriculum, the i.lect program provides 200 hours in 3 years of theoretical and practical education on all aspects of modern dental implantology. We recruited dental students in the i.lect program and additionally students from 15 other universities that voluntarily participated in a single, 3-day implantology camp (R = 58). To demonstrate their knowledge on dental implant issues, both student groups completed a written examination that covered 'Basic information and materials of implantology', 'Implant planning' and 'Soft tissue management'. RESULTS The students in the i.lect program achieved higher scores than students from the implantology camp on questions concerning 'basic implantology' and 'implant planning'. CONCLUSION The results indicated that the structured i.lect undergraduate curriculum enhanced individual knowledge in the specific field of implantology. This program could have pilot character for use in other universities.
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Affiliation(s)
- T Möst
- Department of Oral and Maxillofacial Surgery, University of Erlangen - Nuremberg, Erlangen, Germany.
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26
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Fabricius D, Breckerbohm L, Vollmer A, Queudeville M, Eckhoff SM, Fulda S, Strauss G, Debatin KM, Jahrsdörfer B, Meyer LH. Acute lymphoblastic leukemia cells treated with CpG oligodeoxynucleotides, IL-4 and CD40 ligand facilitate enhanced anti-leukemic CTL responses. Leukemia 2011; 25:1111-21. [PMID: 21527935 DOI: 10.1038/leu.2011.87] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Although the majority of patients initially respond to upfront chemotherapy, relapses with poor prognosis occur in approximately 20% of cases. Thus, novel therapeutic strategies are required to improve long-term survival. B-cell precursor (BCP)-ALL cells express low levels of immunogenic molecules and, therefore, are poorly recognized by the immune system. In the present study, we investigated the effect of various combinations of potent B-cell stimulators including CpG, Interleukin (IL)-2 family cytokines and CD40 ligand (CD40L) on the immunogenicity of primary BCP-ALL cells and a series of BCP-ALL cell lines. The combination of CpG, IL-4 and CD40L was identified as most effective to enhance expression of immunogenic molecules on BCP-ALL cells, resulting in an increased capacity to induce both allogeneic and autologous cytotoxic T lymphocytes (CTL). Importantly, such CTL exhibited significant anti-leukemic cytotoxicity not only towards treated, but also towards untreated BCP-ALL cells. Our results demonstrate that the combination of CpG with other B-cell stimulators is more efficient than CpG alone in generating immunogenic BCP-ALL cells and anti-leukemic CTL. Our results may stimulate the development of novel adoptive T cell transfer approaches for the management of BCP-ALL.
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Affiliation(s)
- D Fabricius
- Department of Pediatrics, University of Ulm, Ulm, Germany.
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27
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Bröker B, Hofmann OT, Rangger GM, Frank P, Blum RP, Rieger R, Venema L, Vollmer A, Müllen K, Rabe JP, Winkler A, Rudolf P, Zojer E, Koch N. Density-dependent reorientation and rehybridization of chemisorbed conjugated molecules for controlling interface electronic structure. Phys Rev Lett 2010; 104:246805. [PMID: 20867325 DOI: 10.1103/physrevlett.104.246805] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Indexed: 05/22/2023]
Abstract
The adsorption of the molecular acceptor hexaazatriphenylene-hexacarbonitrile on Ag(111) was investigated as function of layer density. We find that the orientation of the first molecular layer changes from a face-on to an edge-on conformation depending on layer density, facilitated through specific interactions of the peripheral molecular cyano groups with the metal. This is accompanied by a rehybridization of molecular and metal electronic states, which significantly modifies the interface and surface electronic properties, as rationalized by theoretical modeling.
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Affiliation(s)
- B Bröker
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany
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28
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Peisert H, Biswas I, Aygül U, Vollmer A, Chassé T. Electronic structure of cobalt phthalocyanine studied by resonant photoemission: Localization of Co-related valence band states. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.05.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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30
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Peters S, Peredkov S, Balkaya B, Ferretti N, Savci A, Vollmer A, Neeb M, Eberhardt W. Inner-shell photoionization spectroscopy on deposited metal clusters using soft x-ray synchrotron radiation: an experimental setup. Rev Sci Instrum 2009; 80:125106. [PMID: 20059169 DOI: 10.1063/1.3267193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Exploration of mass-selected clusters by soft x-ray synchrotron radiation is well suited to receive element specific information on clusters in contact with a support and to systematically follow the evolution of size-dependent electronic and geometrical properties from the smallest clusters toward the bulk. Here we describe an experimental setup, which combines cluster synthesis, mass selection, soft landing, ultrahigh vacuum transfer, and photoionization experiments such as x-ray photoelectron spectroscopy, x-ray absorption, and Auger electron spectroscopy. First spectroscopic results and experimental conditions are briefly discussed for Cu(19) deposited onto the natural oxide layer of a Si-wafer surface.
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Affiliation(s)
- S Peters
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus Adlershof, Elektronenspeicherring BESSY II, Albert-Einstein Strasse 15, D-12489 Berlin, Germany
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31
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Thalheim T, Vollmer A, Ebert RU, Kühne R, Schüürmann G. Implication of heteroatom tautomer in QSAR models. Chem Cent J 2009. [DOI: 10.1186/1752-153x-3-s1-p39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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33
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Goodfriend TL, Pedersen TL, Grekin RJ, Hammock BD, Ball DL, Vollmer A. Heparin, lipoproteins, and oxygenated fatty acids in blood: a cautionary note. Prostaglandins Leukot Essent Fatty Acids 2007; 77:363-6. [PMID: 18036802 PMCID: PMC2705328 DOI: 10.1016/j.plefa.2007.10.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We measured 16 nonesterified oxygenated fatty acid derivatives (oxylipids) in plasmas from seven human subjects. Two arterial samples from each subject were analyzed, drawn approximately 2h apart. We observed a marked increase in levels of most oxylipids in the second sample, as high as 470-fold. Between the first and second samples, subjects received approximately 800-1000 IU of heparin to prevent clotting in intravascular catheters. We postulate that heparin activated lipoprotein lipases, which, in turn, released oxylipids from triglycerides and phospholipids in plasma lipoproteins. Some of that lipolysis may have occurred during sample storage. Measurements of nonesterified lipids in human plasma may be distorted if heparin is administered to subjects before blood is drawn and if lipase inhibitors are omitted from stored samples.
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Affiliation(s)
- T L Goodfriend
- William S. Middleton Memorial Veterans Hospital, University of Wisconsin-Madison, 2500 Overlook Terrace, Madison, WI 53705, USA.
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34
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Koch N, Vollmer A, Salzmann I, Nickel B, Weiss H, Rabe JP. Evidence for temperature-dependent electron band dispersion in pentacene. Phys Rev Lett 2006; 96:156803. [PMID: 16712184 DOI: 10.1103/physrevlett.96.156803] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Indexed: 05/09/2023]
Abstract
Evidence for temperature-dependent electron band dispersion in a pentacene thin film polymorph on graphite is provided by angle- and energy-dependent ultraviolet photoelectron spectroscopy. The bands derived from the highest occupied molecular orbital exhibit dispersion of approximately 190 meV at room temperature, and approximately 240 meV at 120 K. Intermolecular electronic coupling in pentacene thin films is thus confirmed to be dependent on temperature and possibly crystal structure, as suggested by additional infrared absorption measurements.
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Affiliation(s)
- N Koch
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany.
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36
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Vollmer A, Jurchescu OD, Arfaoui I, Salzmann I, Palstra TTM, Rudolf P, Niemax J, Pflaum J, Rabe JP, Koch N. The effect of oxygen exposure on pentacene electronic structure. Eur Phys J E Soft Matter 2005; 17:339-43. [PMID: 15968478 DOI: 10.1140/epje/i2005-10012-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 04/21/2005] [Indexed: 05/03/2023]
Abstract
We use ultraviolet photoelectron spectroscopy to investigate the effect of oxygen and air exposure on the electronic structure of pentacene single crystals and thin films. It is found that O(2) and water do not react noticeably with pentacene, whereas singlet oxygen/ozone readily oxidize the organic compound. Also, we obtain no evidence for considerable p-type doping of pentacene by O(2) at low pressure. However, oxygen exposure lowers the hole injection barrier at the interface between Au and pentacene by 0.25 eV, presumably due to a modification of the Au surface properties.
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Affiliation(s)
- A Vollmer
- Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m.b.H., Berlin, Germany
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37
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Starke K, Heigl F, Vollmer A, Weiss M, Reichardt G, Kaindl G. X-ray magneto-optics in lanthanides. Phys Rev Lett 2001; 86:3415-3418. [PMID: 11327984 DOI: 10.1103/physrevlett.86.3415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2000] [Indexed: 05/23/2023]
Abstract
Magneto-optical methods in the visible light regime generally lack element specificity, which has become a considerable shortcoming in research on advanced heteromagnetic systems. Using circularly polarized soft x rays tuned to a 4d-4f core-level transition of a lanthanide element, the specularly reflected x-ray intensity changes proportionally to the magnetization of this element and, e.g., hystereses are easily measured element specifically. In contrast to the case of visible light, temperature dependent 4d-4f magneto-optical signals are not influenced by the thermal lattice expansion.
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Affiliation(s)
- K Starke
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
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Abstract
Dietary fat contributes to the elevation of blood pressure and increases the risk of stroke and coronary artery disease. Previous observations have shown that voltage-gated Ca(2+) current density is significantly increased in hypertension and can be affected by free fatty acids (FAs). We hypothesized that a diet of elevated fat level would lead to an increase in blood pressure, an elevation of L-type Ca(2+) current, and an increase in saturated FA content in vascular smooth muscle cell membranes. Male Osborne-Mendel rats were fed normal rat chow or a high-fat diet (Ob/HT group) for 8 weeks. Blood pressures in the Ob/HT group increased moderately from 122.5+/-0.7 to 134.4+/-0.8 mm Hg (P<0.05, n=26). Voltage-clamp examination of cerebral arterial cells revealed significantly elevated L-type Ca(2+) current density in the Ob/HT group. Voltage-dependent inactivation of the Ob/HT L-type channels was significantly delayed. Total serum FA contents were significantly elevated in the Ob/HT group, and HPLC analyses of fractional pools of FAs from segments of abdominal aorta revealed that arachidonic acid levels were elevated in the phospholipid fraction in Ob/HT. No differences in vascular membrane cholesterol contents were noted. Plasma cholesterol was significantly elevated in portal venous and cardiac blood samples from Ob/HT rats. These findings suggest that an elevation of plasma FAs may contribute to the development of hypertension via a process involving the elevation of Ca(2+) current density and an alteration of channel kinetics in the vascular smooth muscle membrane.
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Affiliation(s)
- D W Wilde
- Bristol-Myers Squibb, US Pharmaceuticals, Ann Arbor, MI 48105, USA.
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39
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Abstract
Heart failure is characterized not only by systolic, but also by diastolic dysfunction. The present study tested whether or not diastolic dysfunction is associated with changes in tissue properties and collagen network structure. Heart failure was induced in seven chronically instrumented, conscious dogs by rapid left ventricular pacing (2 50 min(-1)). After 2-5 [mean: 4+/-1 (S.D.)] weeks pacing, heart failure was apparent from clinical symptoms (ascites, cachexia, edema, exercise intolerance) and hemodynamic parameters (significant increases of heart rate and left ventricular end-diastolic pressure and decreases of left ventricular maximal pressure, dP/dtmax and systolic wall thickening). The left ventricle was dilated, as indicated by a decrease of end-diastolic wall thickness (6.3+/-2.0 v 7.2+/-2.1 mm; P<0.05; sonomicrometry). The left ventricular end-diastolic pressure-strain relation (strain: relative change of end-diastolic wall thickness) was obtained during alterations of loading conditions by inferior caval vein and descending thoracic aortic occlusion. The slope of this relation increased from 85+/-20 to 428+/-188 in heart failure, indicating an increase of left ventricular stiffness. Collagen was stained with picrosirius red and analyzed using polarized light microscopy. In heart failure, the collagen volume fraction remained unchanged (1.9+/-1.2 v 2.3+/-1.3%; N.S.), while the nonuniformity of collagen orientation, as reflected by its standard deviation, was increased (11.1+/-1.8 v 6.1+/-0.4 o; P<0.05). The nonuniformity of collagen fiber orientation correlated with left ventricular stiffness [r=0.75].
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Affiliation(s)
- T Neumann
- Department of Pathophysiology, Center of Internal Medicine, University of Essen, FRG
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40
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von Recklinghausen G, Schmid EN, Vollmer A, Ansorg R. Morphological effects of miconazole on Helicobacter pylori. Antimicrob Agents Chemother 1998; 42:725-6. [PMID: 9517964 PMCID: PMC105530 DOI: 10.1128/aac.42.3.725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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41
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Blanchard EB, Hickling EJ, Buckley TC, Taylor AE, Vollmer A, Loos WR. Psychophysiology of posttraumatic stress disorder related to motor vehicle accidents: replication and extension. J Consult Clin Psychol 1996. [PMID: 8803364 DOI: 10.1037//0022-006x.64.4.742] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Psychophysiological assessment data, including heart rate (HR), blood pressure, and frontal electromyogram (EMG) responses to mental arithmetic, idiosyncratic audiotape descriptions of motor vehicle accidents (MVAs), and a standard videotape of MVAs, were collected on 105 injured victims of recent MVAs and 54 non-MVA controls. Their data replicated data from an earlier report (Blanchard et al., 1994) and support the utility of HR response to the audiotaped description of the MVA as useful in distinguishing MVA victims with PTSD from those with subsyndromal PTSD and non-PTSD. At a 1-year follow-up, the psychophysiological assessment was repeated on 125 MVA victims; results showed a general diminution of psychophysiological responding. Initial psychophysiological assessment results predicted 1-year follow-up clinical status (continued PTSD or full or partial remission) for 37 or 48 individuals who initially met criteria for PTSD.
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Affiliation(s)
- E B Blanchard
- Center for Stress and Anxiety Disorders, University at Albany, State University of New York 12203, USA
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42
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Blanchard EB, Hickling EJ, Buckley TC, Taylor AE, Vollmer A, Loos WR. Psychophysiology of posttraumatic stress disorder related to motor vehicle accidents: replication and extension. J Consult Clin Psychol 1996; 64:742-51. [PMID: 8803364 DOI: 10.1037/0022-006x.64.4.742] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Psychophysiological assessment data, including heart rate (HR), blood pressure, and frontal electromyogram (EMG) responses to mental arithmetic, idiosyncratic audiotape descriptions of motor vehicle accidents (MVAs), and a standard videotape of MVAs, were collected on 105 injured victims of recent MVAs and 54 non-MVA controls. Their data replicated data from an earlier report (Blanchard et al., 1994) and support the utility of HR response to the audiotaped description of the MVA as useful in distinguishing MVA victims with PTSD from those with subsyndromal PTSD and non-PTSD. At a 1-year follow-up, the psychophysiological assessment was repeated on 125 MVA victims; results showed a general diminution of psychophysiological responding. Initial psychophysiological assessment results predicted 1-year follow-up clinical status (continued PTSD or full or partial remission) for 37 or 48 individuals who initially met criteria for PTSD.
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Affiliation(s)
- E B Blanchard
- Center for Stress and Anxiety Disorders, University at Albany, State University of New York 12203, USA
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43
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Blanchard EB, Eisele G, Vollmer A, Payne A, Gordon M, Cornish P, Gilmore L. Controlled evaluation of thermal biofeedback in treatment of elevated blood pressure in unmedicated mild hypertension. Biofeedback Self Regul 1996; 21:167-90. [PMID: 8805965 DOI: 10.1007/bf02284694] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the first of two studies, 42 unmedicated mild hypertensives completed either 16 sessions of thermal biofeedback (TBF) training for hand (7 sessions) and foot (9 sessions) warming or 8 weeks of monitoring BPs at home. There was a trend (p < .10) for more of those treated (57.1%) to have DBPs lower than 90 mm Hg than for those only monitoring BPs at home (33%). Analyses of clinic BP values from random zero sphygmomanometer measurements, from 24-hour ambulatory BP monitoring, and from home BP measurements made by the patient showed no advantage for treatment versus BP monitoring. Sixteen of the 21 patients in BP monitoring were later treated. Analyses of treatment effects across all treated subjects by gender revealed a significant (p = .02) decrease in DBP for treated female subjects (n = 13) but not for males (n = 24). In the second study the 22 initial treatment successes, that is, those whose DBP was below 90 mm Hg at posttreatment (59.4% of those who completed treatment), were randomized to an intensive follow-up (monthly visits for 6 months, then visits every two months) emphasizing regular home practice with an electronic TBF device or regular follow-up (visits every 3 months). Twelve of the 22 were still normotensive at 12 months. There were no differences at any point during the follow-up between the two conditions in success rate or BPs despite a numerical advantage in reported frequency of home practice by those in the intensive follow-up condition.
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Affiliation(s)
- E B Blanchard
- Center for Stress and Anxiety Disorders, University at Albany, New York 12203, USA
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44
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Mølbak K, Aaby P, Ingholt L, Højlyng N, Gottschau A, Andersen H, Brink L, Gansted U, Permin A, Vollmer A. Persistent and acute diarrhoea as the leading causes of child mortality in urban Guinea Bissau. Trans R Soc Trop Med Hyg 1992; 86:216-20. [PMID: 1440794 DOI: 10.1016/0035-9203(92)90580-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An investigation of child mortality in a semi-urban community, Bandim II, in the capital of Guinea Bissau was carried out from April 1987 to March 1990. 153 deaths were recorded among 1426 live-born children who were followed for 2753 child-years. The under-five mortality risk was 215 per 1000 children (95% confidence interval [CI] 176-264), infant mortality 94 per 1000 (95% CI 73-115), and perinatal mortality 52 per 1000 (95% CI 41-63). By prospective registration of morbidity, post-mortem interviews, and examination of available hospital records, a presumptive cause of death was established in 86% of the deaths. Persistent and acute diarrhoea were the most frequent causes of death, accounting for 43 and 31 deaths per 1000 children, respectively. Fever deaths (possibly malaria), neonatal deaths, acute respiratory infections, and measles were other frequent causes. The access to health services was relatively easy: 75% of the children who died had attended for treatment at a hospital or a health centre. It is important to find ways of preventing and managing persistent diarrhoea, the major cause of death, and to improve the control of acute diarrhoea by a targeted approach.
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Affiliation(s)
- K Mølbak
- Laboratory of Parasitology, Statens Seruminstitut, Copenhagen, Denmark
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45
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