122 results on '"Heumann, C."'
Search Results
2. Influence of the internal anatomy on the leakage of root canals filled with thermoplastic technique
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Al-Jadaa, Anas, Attin, T., Peltomäki, T., Heumann, C., Schmidlin, P. R., and Paquè, F.
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- 2018
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3. Prevalence of Candida albicans and Candida dubliniensis in caries-free and caries-active children in relation to the oral microbiota—a clinical study
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Al-Ahmad, A., Auschill, T. M., Dakhel, R., Wittmer, A., Pelz, K., Heumann, C., Hellwig, E., and Arweiler, N. B.
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- 2016
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4. Performance of double [formula omitted]-class estimators for coefficients in linear regression models with non-spherical disturbances under asymmetric losses
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Shalabh, Garg, G., and Heumann, C.
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- 2012
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5. Weather and air pollutants have an impact on patients with respiratory diseases and breathing difficulties in Munich, Germany
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Wanka, E. R., Bayerstadler, A., Heumann, C., Nowak, D., Jörres, R. A., and Fischer, R.
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- 2014
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6. A Review on Joint Models in Biometrical Research
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Neuhaus, A., Augustin, T., Heumann, C., and Daumer, M.
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- 2009
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7. Effect of N-chlorotaurine mouth rinses on plaque regrowth and plaque vitality
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Lorenz, K., Mayer, D., Bruhn, G., Noack, B., Brecx, M., Heumann, C., Toutenburg, H., Netuschil, L., Nagl, M., Gottardi, W., and Hoffmann, T.
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- 2009
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8. Application of Stein-Rule Estimation to Linear Regression Models with Some Missing Observations
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Toutenburg, H., Srivastava, V. K., and Heumann, C.
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- 2006
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9. Use of prior information in the form of interval constraints for the improved estimation of linear regression models with some missing responses
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Toutenburg, H., Shalabh, and Heumann, C.
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- 2006
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10. Influence of pattern of menopausal transition on the amount of trabecular bone loss: Results from a 6-year prospective longitudinal study
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Seifert-Klauss, V., Link, T., Heumann, C., Luppa, P., Haseitl, M., Laakmann, J., Rattenhuber, J., and Kiechle, M.
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- 2006
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11. Effect of two new chlorhexidine mouthrinses on the development of dental plaque, gingivitis, and discolouration. A randomized, investigator-blind, placebo-controlled, 3-week experimental gingivitis study
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Lorenz, K., Bruhn, G., Heumann, C., Netuschil, L., Brecx, M., and Hoffmann, T.
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- 2006
12. JURISPRUDENCE
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HEUMANN, C. and LIET-VEAUX, G.
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- 1955
13. The effect of green tea as an adjunct to scaling and root planing in non-surgical periodontitis therapy: a systematic review.
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Gartenmann, S. J., Weydlich, Y. v., Steppacher, S. L., Heumann, C., Attin, T., and Schmidlin, Patrick R.
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MEDICINE ,META-analysis ,EPIGALLOCATECHIN gallate ,RELEVANCE - Abstract
Objective: To provide a systematic overview on the efficacy of green tea catechin as an adjunct to scaling and root planing (SRP) in terms of probing pocket depth (PPD).Materials and methods: A systematic literature search was performed using electronic databases in PubMed, Scopus, Medline, Cochrane, CINAHL, and Web of Science on randomized clinical trials up to January 2017. The research question was posed in accordance with PRISMA guidelines.Results: The search provided 234 studies. After analyzing the full texts, five studies were included, with four studies qualifying for meta-analysis. Mean PPD reduction was significantly higher (α = 0.05) when green tea catechin was used as an adjunct to SRP (test group) than with SRP alone (control group). The difference in the reduction was 0.74 mm [0.35-1.13; 95% CI].Conclusion: The local application of green tea catechin as an adjunct to SRP may result in a beneficial reduction in PPD. Due to the highly heterogeneous data and some risk of bias, however, this data still needs to be interpreted with caution.Clinical relevance: The finding suggests that green tea catechin may be a topical adjunct to SRP without negative side effects. [ABSTRACT FROM AUTHOR]
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- 2019
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14. Stein-rule estimation under an extended balanced loss function.
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Toutenburg, H. and Heumann, C.
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ESTIMATION theory , *REGRESSION analysis , *LEAST squares , *MATHEMATICAL statistics , *PITMAN'S measure of closeness , *STATISTICAL correlation - Abstract
This paper extends the balanced loss function to a more general setup. The ordinary least squares estimator (OLSE) and Stein-rule estimator (SRE) are exposed to this general loss function with quadratic loss structure in a linear regression model. Their risks are derived when the disturbances in the linear regression model are not necessarily normally distributed. The dominance of OLSE and SRE over each other and the effect of departure from normality assumption of disturbances on the risk property are studied. [ABSTRACT FROM AUTHOR]
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- 2009
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15. Exposure to Noise and Well-being in South Germany.
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Meyer, N, Spegel, H, Kreuzmaier, I, Schulze, A, Heumann, C, Vonkries, R, Nowak, D, and Radon, K
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- 2006
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16. P1H196 - Programme for the prevention of health hazards caused by industrial substances — Results of the toxicological evaluation of chemicals
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Beth-Huebner, M., Frohberg, H., Martens, G., Heumann, C., Bartels, K., and Radek, E.
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- 1998
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17. TakeMeHome: A novel method for reaching previously untested people through online ordering and self-collect HIV and STI testing.
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Hecht J, Facente SN, Cohen S, Menza T, Trainor N, Heumann C, Juhasz M, and Sullivan P
- Abstract
Background: Despite national testing guidelines, rates of testing for HIV, sexually transmitted infections, and hepatitis C remain lower than recommended for men who have sex with men (MSM) in the US. To help address this, the TakeMeHome (TMH) program was started in March 2020 by a consortium of public health organizations and dating apps - Building Healthy Online Communities - to work with health departments to increase access to HIV testing for MSM on dating apps., Methods: Users of participating dating apps were sent messages about opportunities for testing with self-collected specimens through TMH. Program users were eligible to receive test kits if they lived in a participating zip code and were aged at least 18. Users who were interested in testing could order kits to be mailed to them for lab-based testing of HIV, hepatitis C, chlamydia, gonorrhea, and/or syphilis, depending on risk and availability in their zip code. Orders were sent via application programming interface (API) to Molecular Testing Labs (MTL) for fulfillment; kits were provided at no cost to the program user. Within approximately 24 hours of order receipt, MTL mailed program users a kit with required collection supplies, directions, and a link to a video instruction for self-collection. Program users received an automated email after testing was complete with a link to access results through their online account. Individuals with positive results on any of the relevant tests were directed to additional information and supported with linkage to additional testing or treatment, depending on local protocols., Results: The positivity rate of specimens processed through TMH was 1.4% for HIV, 0.6% for hepatitis C, and 2.9% for all STIs combined. The per-person positivity rate was 15.3% across all STIs.Conclusions: The TakeMeHome program demonstrates that self-collected lab-processed testing is feasible and effective at identifying new HIV and STI cases., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Sexually Transmitted Diseases Association.)
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- 2024
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18. Sexual Behavior and Sexual Decision-Making Among Gay, Bisexual, and Other Men Who Have Sex with Men During the COVID-19 Pandemic: Observations from a Rapid Ethnographic Assessment in Marion County, Indiana, October-November 2021.
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Loosier PS, Ogale YP, Smith RC, Kachur R, Nicolae L, and Heumann C
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- Male, Humans, Homosexuality, Male psychology, Pandemics, Indiana epidemiology, Sexual Behavior, Sexual and Gender Minorities, HIV Infections prevention & control, COVID-19
- Abstract
From 2020 to 2021, Marion County, Indiana, USA, saw an increase in early syphilis diagnoses, primarily among gay, bisexual, and other men who have sex with men (GBMSM). This rapid ethnographic assessment combines survey data from GBMSM with data from key informant interviews with multiple groups of stakeholders, including GBMSM, to describe how COVID-19 impacted sexual behaviors, sexual decision-making, and access to sexually transmitted disease (STD) services among GBMSM in Marion County, Indiana. A total of 62 virtual, semi-structured qualitative interviews with 72 key respondents including health department staff, medical providers, community-based organization staff, and GBMSM were conducted from October 14 to November 22, 2021. Modifications to partner-seeking and sexual behaviors attributable to the pandemic were associated with the way in which individuals reacted to the pandemic in general. Some GBMSM adopted mitigation strategies to avoid COVID-19 when meeting sex partners, such as creating a "sex pod." Effects on mental health included increased loneliness, heightened anxiety, and a sense of hopelessness regarding the perceived inevitability of acquiring COVID-19. For some, the latter prompted decreased engagement in preventive measures when engaging in sexual activity. The pandemic decreased access to STD services and significantly curtailed public health outreach efforts, which may have limited access to needed STD treatment and care. Efforts focusing on ongoing public health concerns during extreme health events like COVID-19 may want to consider the many ways these events affect ancillary behaviors, such sexual decision-making and sexual behaviors. The role of mental health is key; messaging and guidance may benefit from a trauma-informed approach., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)
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- 2024
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19. The Impact of Implant Abutment Angle and Height on Peri-implant Tissue Health: Retrospective Analyses from a Randomized Controlled Clinical Trial.
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Rathe F, Junker R, Blumenröhr J, Martin L, Löhlein N, Heumann C, Auschill T, Arweiler N, and Schlee M
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- Humans, Dental Abutments, Retrospective Studies, Titanium, Randomized Controlled Trials as Topic, Dental Implants, Peri-Implantitis etiology
- Abstract
Purpose: To examine the influence of abutment emergence angle and abutment height on marginal peri-implant bone stability in patients not considered susceptible to peri-implantitis. Furthermore, it was analyzed whether titanium-base (Ti-base) abutments lead to wider abutment emergence angles compared to one-piece abutments., Materials and Methods: A total of 48 abutments (ie, 24 Ti-base and 24 one-piece abutments in 24 patients) were evaluated at abutment installation, after 1 year, and thereafter on a yearly basis for up to 5 years. Clinical and radiographic outcome variables were assessed., Results: With regard to peri-implant marginal bone stability, only moderately negative, albeit significant, correlations were found on the mesial sides of the one-piece abutments after 4 and 5 years for an abutment emergence angle > 30 degrees. No statistically significant negative correlations were found for distances of ≤ 1.5 mm between the restoration margin and the crestal peri-implant bone level for either Ti-base or for one-piece abutments. Furthermore, abutments bonded to Ti-bases were not associated with larger emergence angles than one-piece abutments., Conclusions: For patients at low risk of developing peri-implantitis, it can be concluded that neither a larger abutment emergence angle (> 30 degrees) nor a distance of ≤ 1.5 mm between the restoration margin and the crestal peri-implant bone level are associated with marginal peri-implant bone loss. Furthermore, abutments bonded to Ti-bases are not associated with wider emergence angles than one-piece abutments.
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- 2024
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20. Glucose-6-Phosphatase-Dehydrogenase activity as modulative association between Parkinson's disease and periodontitis.
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Laugisch O, Ruppert-Jungck MC, Auschill TM, Eick S, Sculean A, Heumann C, Timmermann L, Pedrosa DJ, Eggers C, and Arweiler NB
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- Humans, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Inflammation, Porphyromonas gingivalis, Prevotella intermedia, RNA, Parkinson Disease complications, Periodontitis complications, Glucosephosphate Dehydrogenase genetics, Glucosephosphate Dehydrogenase metabolism
- Abstract
The association between periodontitis (PD) and Parkinson's disease (PK) is discussed due to the inflammatory component of neurodegenerative processes. PK severity and affected areas were determined using the following neuropsychological tests: Unified Parkinson's Disease Rating Score (UPDRS) and Hoehn and Yahr; non-motoric symptoms by Non-Motor Symptoms Scale (NMSS), and cognitive involvement by Mini-Mental State Examination (MMSE). Neuroinflammation and the resulting Glucose-6-Phosphatase-Dehydrogenase (G6PD) dysfunction are part of the pathophysiology of PK. This study aimed to evaluate these associations in periodontal inflammation. Clinical data and saliva-, serum-, and RNA-biobank samples of 50 well-characterized diametric patients with PK and five age- and sex-matched neurologically healthy participants were analyzed for G6PD function, periodontal pathogens ( Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum , and Filifactor alocis) , monocyte chemoattractant protein (MCP) 1, and interleukin (IL) 1-beta. Regression analysis was used to identify associations between clinical and behavioral data, and t-tests were used to compare health and disease. Compared with PK, no pathogens and lower inflammatory markers (p < 0.001) were detectible in healthy saliva and serum, PK-severity/UPDRS interrelated with the occurrence of Prevotella intermedia in serum as well as IL1-beta levels in serum and saliva (p = 0.006, 0.019, 0.034), Hoehn and Yahr correlated with Porphyromonas gingivalis , Prevotella intermedia , RNA IL1-beta regulation, serum, and saliva IL1-beta levels, with p-values of 0.038, 0.011, 0.008, <0.001, and 0.010, while MMSE was associated with Aggregatibacter actinomycetemcomitans , Fusobacterium nucleatum , serum MCP 1 levels, RNA IL1-beta regulation and G6PD serum activity (p = 0.036, 0.003, 0.045, <0.001, and 0.021). Cognitive and motor skills seem to be important as representative tests are associated with periodontal pathogens and oral/general inflammation, wherein G6PD-saliva dysfunction might be involved., Clinical Trial Registration: https://www.bfarm.de/DE/Das-BfArM/Aufgaben/Deutsches-Register-Klinischer-Studien/_node.html, identifier DRKS00005388., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Laugisch, Ruppert-Jungck, Auschill, Eick, Sculean, Heumann, Timmermann, Pedrosa, Eggers and Arweiler.)
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- 2024
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21. Retrospective analysis of augmentation procedures with umbrella screws, a novel tenting technique: a consecutive case series in 279 patients.
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Stumpf T, Rathe F, Heumann C, Sader R, and Schlee M
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- Humans, Retrospective Studies, Bone Transplantation methods, Postoperative Complications, Dental Implantation, Endosseous methods, Alveolar Ridge Augmentation methods
- Abstract
Objectives: The consecutive case series accesses the results and experiences of ridge augmentation using an umbrella screw tenting technique., Method and Materials: In total, 279 patients were treated between 26 May 2015 and 16 June 2021, including horizontal and vertical ridge defects. Sex, age, smoking behavior, jaw, graft material, soft tissue thickness, extent of horizontal/vertical augmentation, resorption rate, and occurrence of early/late exposure were evaluated. Bone gain was determined by resorption at the screw head. Only cases without premature screw removal were evaluated metrically (n = 201). All other augmentations were evaluated according to whether implantation was possible with or without further augmentation (n = 27). A target performance index was calculated, which should enable evidence-based comparability of different augmentation methods in future., Results: In total, 54 wound dehiscences (39 early, 15 late exposures) occurred, which corresponds to 24.08% of the augmented sites; 42 umbrella screws were removed prematurely. In all cases an implantation was possible at the desired position afterwards. Cases with a vertical augmentation component showed a higher prevalence of exposure (early, P = .000; late, P = .024). The extent of the vertical augmentation was only relevant for early exposure (P = .048). Mean bone gain of 4.23 ± 1.69 mm horizontally and 4.11 ± 1.99 mm vertically could be achieved. Regression analysis showed that there was no limit in horizontal/vertical direction. Mean percentage target performance index was 75.90 ± 20.54 for vertical and 82.25 ± 16.67 for horizontal portions., Conclusion: The umbrella technique is an effective augmentation method, which can be applied to any defect morphology.
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- 2024
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22. Association between Average Vitamin D Levels and COVID-19 Mortality in 19 European Countries-A Population-Based Study.
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Ahmad AS, Juber NF, Al-Naseri H, Heumann C, Ali R, and Oliver T
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- Humans, Vitamin D, Vitamins, Research Design, COVID-19, Vitamin D Deficiency epidemiology
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Early epidemic reports have linked low average 25(OH) vitamin D levels with increased COVID-19 mortality. However, there has been limited updated research on 25(OH) vitamin D and its impact on COVID-19 mortality. This study aimed to update the initial report studying the link between vitamin D deficiency and COVID-19 mortality by using multi-country data in 19 European countries up to the middle of June 2023. COVID-19 data for 19 European countries included in this study were downloaded from Our World in Data from 1 March 2020, to 14 June 2023, and were included in the statistical analysis. The 25(OH) vitamin D average data were collected by conducting a literature review. A generalized estimation equation model was used to model the data. Compared to European countries with 25(OH) vitamin D levels of ≤50 nmol/L, European countries with 25(OH) vitamin D average levels greater than 50 nmol/L had lower COVID-19 mortality rates (RR = 0.794, 95% CI: 0.662-0.953). A statistically significant negative Spearman rank correlation was observed between 25(OH) vitamin D average levels and COVID-19 mortality. We also found significantly lower COVID-19 mortality rates in countries with high average 25(OH) vitamin D levels. Randomized trials on vitamin D supplementation are needed. In the meantime, the issue of vitamin D use should be debated in relation to the ongoing discussions of national post-COVID-19 resilience against future pandemics.
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- 2023
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23. Using interpretable boosting algorithms for modeling environmental and agricultural data.
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Obster F, Heumann C, Bohle H, and Pechan P
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We describe how interpretable boosting algorithms based on ridge-regularized generalized linear models can be used to analyze high-dimensional environmental data. We illustrate this by using environmental, social, human and biophysical data to predict the financial vulnerability of farmers in Chile and Tunisia against climate hazards. We show how group structures can be considered and how interactions can be found in high-dimensional datasets using a novel 2-step boosting approach. The advantages and efficacy of the proposed method are shown and discussed. Results indicate that the presence of interaction effects only improves predictive power when included in two-step boosting. The most important variable in predicting all types of vulnerabilities are natural assets. Other important variables are the type of irrigation, economic assets and the presence of crop damage of near farms., (© 2023. Springer Nature Limited.)
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- 2023
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24. Variability of clinical chemical and hematological parameters, immunological parameters, and behavioral tests in data sets of the Mouse Phenome Database.
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Aigner B and Heumann C
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- Animals, Mice, Correlation of Data, Databases, Factual, Genetic Background, Behavior Rating Scale, Biomedical Research
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The use of mice as animal models in biomedical research allows the standardization of genetic background, housing conditions as well as experimental protocols, which all affect phenotypic variability. The phenotypic variability within the experimental unit determines the choice of the group size which is necessary for achieving valid and reproducible results. In this study, the variability of clinical chemical and hematological parameters which represent a comprehensive blood screen of laboratory mice, as well as of immunological parameters and behavioral tests was analyzed in data sets which have been submitted to the Mouse Phenome Database for mouse strains which are predominantly used in biomedical research. Most of the clinical chemical and hematological parameters-except of some parameters being known for their high variability-showed an average coefficient of variation (CV = standard deviation / mean) below 0.25. Most immunological parameters measured in blood samples had a CV between 0.2 and 0.4. The behavioral tests showed a CV between 0.4 and 0.6, or higher. In addition, a large range of the CV was found for most parameters/tests between and within the selected projects. This clearly demonstrates the appearance of unpredictable major interactions between genotype, environment and experiment regarding the variability of the parameters and tests analyzed., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Aigner, Heumann. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2023
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25. Patient characteristics and testing over COVID-19 waves 1 and 2 from the first German COVID-19 testing unit in Munich, Germany.
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Srinivasan H, Hohl HT, Heumann C, and Froeschl G
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- Female, Humans, Adult, COVID-19 Testing, SARS-CoV-2, Germany epidemiology, Public Health, COVID-19 diagnosis, COVID-19 epidemiology
- Abstract
Background: In Munich, the first German case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected on 27 January 2020 at the Division of Infectious Diseases and Tropical Medicine of the University Hospital LMU Munich (DIDTM), and consecutively the Covid Testing Unit was established. Germany advocated several public health measures to control the outbreak. This study investigates the effects of measures on health service utilization in the public, which in turn can alter case numbers and test positivity rates., Method: Our retrospective observational study was conducted to determine the effects of public health measures on the utilization of a testing facility and positivity rates from the first operational COVID-19 testing facility in Munich for waves 1 and 2 over a period of 14 months. This was accomplished by comparing trends in client characteristics including age, gender, symptoms, and socio-demographic aspects over time to non-pharmaceutical measures in Germany. To depict trend changes in testing numbers over time, we developed a negative binomial model with multiple breakpoints., Results: In total 9861 tests were conducted on 6989 clients. The clients were mostly young (median age: 34), female (60.58%), and asymptomatic (67.89%). Among those who tested positive for SARS-CoV-2, 67.72% were symptomatic while the percentage was 29.06% among those who tested negative. There are other risk factors, but a SARS-CoV-2-positive colleague at work is the most prominent factor. Trend changes in the clients' testing numbers could be attributed to the implementation of various public health measures, testing strategies, and attitudes of individuals toward the pandemic. However, test positivity rates did not change substantially during the second wave of the pandemic., Conclusion: We could show that implementation or changes in public health measures have a strong effect on the utilization of testing facilities by the general public, which independently of the true epidemiological background situation can result in changing test numbers., (© 2023. The Author(s).)
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- 2023
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26. Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life.
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Forster F, Heumann C, Schaub B, Böck A, Nowak D, Vogelberg C, and Radon K
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- Child, Female, Humans, Follow-Up Studies, Bayes Theorem, Risk Factors, Respiratory Sounds etiology, Eczema etiology, Eczema complications, Hypersensitivity etiology, Hypersensitivity complications, Asthma etiology, Asthma complications, Occupational Exposure adverse effects
- Abstract
Purpose: Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life., Methods: We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs., Results: In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested., Conclusions: Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children., (Copyright © 2022 Elsevier Inc. All rights reserved.)
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- 2023
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27. Bone envelope for implant placement after alveolar ridge preservation: a systematic review and meta-analysis.
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Fischer KR, Solderer A, Arlt K, Heumann C, Liu CC, and Schmidlin PR
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- Animals, Cattle, Humans, Alveolar Process surgery, Dental Implants, Bone Resorption, Alveolar Ridge Augmentation, Health Status
- Abstract
Purpose: To assess the dimensional establishment of a bony envelope after alveolar ridge preservation (ARP) with deproteinized bovine bone mineral (DBBM) in order to estimate the surgical feasibility of standard diameter implants placement without any additional augmentation methods., Methods: PubMed, Embase and CENTRAL databases were searched for suitable titles and abstracts using PICO elements. Inclusion criteria were as follows: randomized controlled trials (RCTs) comprising at least ten systemically healthy patients; test groups comprised placement of (collagenated) DBBM w/o membrane and control groups of no grafting, respectively. Selected abstracts were checked regarding their suitability, followed by full-text screening and subsequent statistical data analysis. Probabilities and number needed to treat (NNT) for implant placement without any further need of bone graft were calculated., Results: The initial database search identified 2583 studies. Finally, nine studies with a total of 177 implants placed after ARP with DBBM and 130 implants after SH were included for the quantitative and qualitative evaluation. A mean difference of 1.13 mm in ridge width in favour of ARP with DBBM could be calculated throughout all included studies (95% CI 0.28-1.98, t2 = 1-1063, I2 = 68.0%, p < 0.01). Probabilities for implant placement with 2 mm surrounding bone requiring theoretically no further bone augmentation ranged from 6 to 19% depending on implant diameter (3.25: 19%, RD = 0.19, C = 0.06-0.32, p < 0.01/4.0: 14%, RD = 0.14, C = 0.05-0.23, p < 0.01/5.0: 6%, RD = 0.06, C = 0.00-0.12, p = 0.06)., Conclusion: ARP employing DBBM reduces ridge shrinkage on average by 1.13 mm and improves the possibility to place standard diameter implants with up to 2 mm circumferential bone housing; however, no ARP would have been necessary or additional augmentative bone interventions are still required in 4 out of 5 cases., (© 2022. The Author(s).)
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- 2022
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28. Clinical, microbiological, and immunological effects of 3- or 7-day systemic antibiotics adjunctive to subgingival instrumentation in patients with aggressive (Stage III/IV Grade C) periodontitis: A randomized placebo-controlled clinical trial.
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Cosgarea R, Jepsen S, Heumann C, Batori-Andronescu I, Rosu A, Bora R, Arweiler NB, Eick S, and Sculean A
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- Amoxicillin therapeutic use, Dental Scaling, Humans, Metronidazole therapeutic use, Aggressive Periodontitis drug therapy, Anti-Bacterial Agents
- Abstract
Aim: To evaluate the clinical non-inferiority of a 3-day protocol of systemic antibiotics adjunctive to subgingival instrumentation (SI) compared with a 7-day-protocol in patients with Stage III/IV Grade C periodontitis., Materials and Methods: Fifty systemically healthy patients (32.7 ± 4.3 years) with aggressive periodontitis (AgP; Stage III/IV Grade C periodontitis) were treated by SI and adjunctive amoxicillin and metronidazole and were randomly assigned to Group A: (n = 25) 500 mg antibiotics (AB) 3 times a day for 3 days, followed by placebo 3 times a day for 4 days, or Group B: (n = 25) 500 mg AB 3 times a day for 7 days. Clinical, microbial, and immunological parameters were assessed at baseline, 3 months, and 6 months, and patient-related outcomes were assessed after 2 weeks. The primary outcome variable was the number of residual sites with pocket depth (PD) ≥6 mm at 6 months., Results: For the primary outcome variable (the number of residual sites with PD ≥6 mm at 6 months), the null hypothesis was rejected and non-inferiority of the 3-day AB protocol compared with the 7-day AB protocol was demonstrated (the upper limits of the 95% confidence interval for intention to treat analysis: [-2.572; 1.050] and per protocol analysis: [-2.523; 1.318] were lower than the assumed margin of Δ = 3.1). Comparable clinical improvements were obtained for all parameters with both antibiotic protocols (p > .05). All investigated periodontopathogens and pro-inflammatory host-derived markers were statistically significantly reduced without differences between the treatments (p > .05)., Conclusions: These findings indicate that in patients with AgP (Stage III/IV Grade C periodontitis), a 3-day systemic administration of amoxicillin and metronidazole adjunctive to SI may lead to non-inferior clinical outcomes after 6-months with fewer adverse events compared with a 7-day-protocol., (© 2022 The Authors. Journal of Clinical Periodontology published by John Wiley & Sons Ltd.)
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- 2022
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29. Modelling of a triage scoring tool for SARS-COV-2 PCR testing in health-care workers: data from the first German COVID-19 Testing Unit in Munich.
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Hohl HT, Froeschl G, Hoelscher M, and Heumann C
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- Abdominal Pain, Adult, COVID-19 Testing, Female, Humans, Polymerase Chain Reaction, Retrospective Studies, Triage, COVID-19 diagnosis, SARS-CoV-2 genetics
- Abstract
Background: Numerous scoring tools have been developed for assessing the probability of SARS-COV-2 test positivity, though few being suitable or adapted for outpatient triage of health care workers., Methods: We retrospectively analysed 3069 patient records of health care workers admitted to the COVID-19 Testing Unit of the Ludwig-Maximilians-Universität of Munich between January 27 and September 30, 2020, for real-time polymerase chain reaction analysis of naso- or oropharyngeal swabs. Variables for a multivariable logistic regression model were collected from self-completed case report forms and selected through stepwise backward selection. Internal validation was conducted by bootstrapping. We then created a weighted point-scoring system from logistic regression coefficients., Results: 4076 (97.12%) negative and 121 (2.88%) positive test results were analysed. The majority were young (mean age: 38.0), female (69.8%) and asymptomatic (67.8%). Characteristics that correlated with PCR-positivity included close-contact professions (physicians, nurses, physiotherapists), flu-like symptoms (e.g., fever, rhinorrhoea, headache), abdominal symptoms (nausea/emesis, abdominal pain, diarrhoea), less days since symptom onset, and contact to a SARS-COV-2 positive index-case. Variables selected for the final model included symptoms (fever, cough, abdominal pain, anosmia/ageusia) and exposures (to SARS-COV-positive individuals and, specifically, to positive patients). Internal validation by bootstrapping yielded a corrected Area Under the Receiver Operating Characteristics Curve of 76.43%. We present sensitivity and specificity at different prediction cut-off points. In a subgroup with further workup, asthma seems to have a protective effect with regard to testing result positivity and measured temperature was found to be less predictive than anamnestic fever., Conclusions: We consider low threshold testing for health care workers a valuable strategy for infection control and are able to provide an easily applicable triage score for the assessment of the probability of infection in health care workers in case of resource scarcity., (© 2022. The Author(s).)
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- 2022
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30. Clustering compositional data using Dirichlet mixture model.
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Pal S and Heumann C
- Subjects
- Cluster Analysis, Computer Simulation, Normal Distribution, Algorithms
- Abstract
A model-based clustering method for compositional data is explored in this article. Most methods for compositional data analysis require some kind of transformation. The proposed method builds a mixture model using Dirichlet distribution which works with the unit sum constraint. The mixture model uses a hard EM algorithm with some modification to overcome the problem of fast convergence with empty clusters. This work includes a rigorous simulation study to evaluate the performance of the proposed method over varied dimensions, number of clusters, and overlap. The performance of the model is also compared with other popular clustering algorithms often used for compositional data analysis (e.g. KMeans, Gaussian mixture model (GMM) Gaussian Mixture Model with Hard EM (Hard GMM), partition around medoids (PAM), Clustering Large Applications based on Randomized Search (CLARANS), Density-Based Spatial Clustering of Applications with Noise (DBSCAN) etc.) for simulated data as well as two real data problems coming from the business and marketing domain and physical science domain, respectively. The study has shown promising results exploiting different distributional patterns of compositional data., Competing Interests: The authors have declared that no competing interests exist.
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- 2022
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31. Long-term effects of titanium-base abutments on peri-implant health: A 5-year randomised controlled trial.
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Rathe F, Junker R, Heumann C, Blumenröhr J, Auschill T, Arweiler N, and Schlee M
- Subjects
- Dental Abutments, Humans, Prospective Studies, Single-Blind Method, Dental Implants, Titanium
- Abstract
Purpose: Titanium bases are used frequently in daily practice for bonding to CAD/CAM abutments or crowns. Due to intimate contact between the adhesive gap of the titanium-base abutment and the peri-implant bone, the physical and chemical characteristics of the bonding material, or the gap itself, may affect peri-implant inflammatory reactions. The present study therefore aimed to examine the long-term effects of individualised abutments bonded to titanium bases on peri-implant health., Materials and Methods: A total of 24 patients, each with one test and one control abutment, participated in the present prospective, single-blind, randomised controlled clinical trial. The test abutments were CAD/CAM titanium abutments bonded to titanium bases. As the control abutments were individualised, one-piece CAD/CAM titanium abutments were used. Clinical and radiographic parameters were assessed at abutment insertion and then on a yearly basis over the following 5 years., Results: No significant differences in marginal bone level were observed between the titanium-base and one-piece abutments at any of the follow-up time points; however, when intragroup marginal bone levels were compared to the baseline values, significant differences were found at several follow-up time points. Intergroup differences were only found to be significant for pocket depth at the 4- (P = 0.006) and 5-year follow-ups (P = 0.024), favouring titanium-base abutments., Conclusions: Within the limitations of the present study, it appears that the peri-implant tissues of this specific patient cohort responded to titanium-base abutments in a rather similar manner to one-piece abutments over a 5-year period; however, no definitive conclusions can be drawn due to the low power of the present study.
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- 2022
32. COVID-19 Testing Unit Munich: Impact of Public Health and Safety Measures on Patient Characteristics and Test Results, January to September 2020.
- Author
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Hohl HT, Heumann C, Rothe C, Hoelscher M, Janke C, and Froeschl G
- Subjects
- Adult, COVID-19 Testing, Female, Humans, Male, Middle Aged, Public Health, Retrospective Studies, SARS-CoV-2, COVID-19 diagnosis, COVID-19 epidemiology, Pandemics
- Abstract
To assess the course of the COVID-19 pandemic and the impact of non-pharmaceutical interventions, the number of reported positive test results is frequently used as an estimate of the true number of population-wide infections. We conducted a retrospective observational analysis of patient data of the Corona Testing Unit (CTU) in Munich, Bavaria, Germany between January 27th, and September 30th, 2020. We analyzed the course of daily patient numbers over time by fitting a negative binomial model with multiple breakpoints. Additionally, we investigated possible influencing factors on patient numbers and characteristics by literature review of policy papers and key informant interviews with individuals involved in the set-up of the CTU. The 3,963 patients included were mostly young (median age: 34, interquartile range: 27-48), female (66.2%), and working in the healthcare sector (77%). For these, 5,314 real-time RT-PCR tests were conducted with 157 (2.94%) positive results. The overall curve of daily tests and positive results fits the re-ported state-wide incidence in large parts but shows multiple breakpoints with considerable trend changes. These can be most fittingly attributed to testing capacities and -strategies and individual risk behavior, rather than public health measures. With the large impact on patient numbers and pre-test probabilities of various strategic and operational factors, we consider the derived re-ported incidence as a poor measurement to base policy decisions on. Testing units should be prepared to encounter these fluctuations with a quickly adaptable structure., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hohl, Heumann, Rothe, Hoelscher, Janke and Froeschl.)
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- 2022
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33. Gingival phenotype distribution in young Caucasian women and men - An investigative study.
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Fischer KR, Büchel J, Kauffmann F, Heumann C, Friedmann A, and Schmidlin PR
- Subjects
- Adult, Female, Humans, Male, Phenotype, Tooth Crown, White People, Young Adult, Gingiva, Incisor
- Abstract
Objectives: To evaluate the relationship between gingival phenotype and tooth location based on selected index teeth ("Ramfjord") and assess possible differences between women and men., Material and Methods: Thirty-six women and 20 men voluntarily participated in this investigation with an average age of 23 years (min: 19; max: 37). Gingival phenotypes (GP) were assessed by transparency of a periodontal probe through the buccal gingival margin., Results: A comparable and similar GP on all index teeth was only found in seven out of the 56 subjects, that is, thin or thick only: Five participants (three male/two female) showed a uniform and constantly thick and two females a constantly thin GP. While the majority of molars (94.6%; p = 0.006) showed a thick GP, premolars (61.6%; p = 0.09) as well as incisors (70.5%; p = 0.046) were predominantly categorized as thin. In addition, significantly thicker GP was in general observed for maxillary teeth (p = 0.001) but without differences between genders (p = 0.722)., Conclusion: No constant GP can be expected within one dentition. The use of the "Ramfjord teeth" may serve as a quick overview and reliable method to screen GP distribution., (© 2021 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)
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- 2022
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34. Clinical Evaluation of a New Electronic Periodontal Probe: A Randomized Controlled Clinical Trial.
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Laugisch O, Auschill TM, Heumann C, Sculean A, and Arweiler NB
- Abstract
Precise measurements of periodontal parameters (such as pocket depths: PPD, gingival margins: GM) are important for diagnosis of periodontal disease and its treatment. Most examiners use manual millimeter-scaled probes, dependent on adequate pressure and correct readouts. Electronic probes aim to objectify and facilitate the diagnostic process. This randomized controlled trial compared measurements of a standard manual (MP) with those of an electronic pressure-sensitive periodontal probe (EP) and its influence on patients' acceptance and practicability. In 20 patients (2436 measuring points) PPD and GM were measured either with MP or EP by professionals with different levels of experience: dentist (10 patients), 7th and 10th semester dental students (5 patients each). Time needed was measured in minutes and patients' subjective pain was evaluated by visual analogue scale. Differences were analyzed using the generalized estimating equations approach (GEE) and paired Wilcoxon tests. Mean PPD varied with ΔPPD 0.38 mm between both probes, which was significant ( p < 0.001), but GM did not (ΔREC 0.07 mm, p = 0.197). There was a statistically significant correlation of both probes (Spearman's rho correlation coefficient GM: 0.674, PPD: 0.685). Differences can be considered robust (no deviation in either direction). The comparison of time needed and pain sensitivity did not result in statistically significant differences ( p > 0.05).
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- 2021
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35. Tricalcium phosphate (-containing) biomaterials in the treatment of periodontal infra-bony defects: A systematic review and meta-analysis.
- Author
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Liu CC, Solderer A, Heumann C, Attin T, and Schmidlin PR
- Subjects
- Biocompatible Materials therapeutic use, Calcium Phosphates, Follow-Up Studies, Guided Tissue Regeneration, Periodontal, Humans, Periodontal Attachment Loss, Treatment Outcome, Alveolar Bone Loss diagnostic imaging, Alveolar Bone Loss surgery, Bone Substitutes therapeutic use
- Abstract
Objectives: This study aimed to investigate the additional clinical benefit of tricalcium phosphate (TCP) (-containing) biomaterials compared to open flap debridement (OFD) in periodontal infra-bony defects., Data: A literature search was conducted in Pubmed, Embase and Cochrane library for entries published up to 14th July 2021. All randomized controlled trials (RCTs) that compared a TCP (-containing) material with OFD and studies that assessed a beta-TCP group alone, with vertical defect sites with PPD of ≥ 6 mm and/or presence of infra-bony defects of ≥ 3 mm and a minimum follow-up of 6 months were included. Risk of bias was assessed with the Oxford scale. The random-effects (RE) model was synthesized as differences between weighted average (MD) for probing pocket depth (PPD) and clinical attachment level (CAL) between TCP and OFD groups. An RE analysis was also performed for the beta-TCP group alone., Study Selection: Data from 16 RCTs were included in the analysis. Six studies that represented 151 patients and sites were selected for meta-analysis. The overall MD with 95% CI at 6 months was calculated to be -0.47 [-0.83, -0.12; P = 0.0087] and -1.06 [-1.67, -0.46; P = 0.0006] for PPD and CAL, respectively. Whereas MD at 12 months for PPD and CAL was -0.89 [-1.54, -0.23; P = 0.0078] and -1.25 [-1.85, -0.66; P<0.0001], respectively. All results were in favor of TCP (-containing) group over OFD., Conclusions: The results of the study suggest that the use of a TCP (-containing) material may have the potential for additional clinical improvement in PPD and CAL compared with OFD in infra-bony defects, given the limitations of the included evidence., Clinical Significance: The use of TCP as a bone graft substitute is becoming increasingly common. Therefore, it would be advantageous if an adjunctive benefit in the regeneration of infra-bony defects could be demonstrated to facilitate material selection., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
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- 2021
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36. Antibacterial Action, Substantivity and Anti-plaque Effect of Different Toothpaste Slurries - A Randomised Controlled Trial.
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Arweiler NB, Müller-Breitenkamp F, Heumann C, Laugisch O, and Auschill TM
- Subjects
- Anti-Bacterial Agents therapeutic use, Cross-Over Studies, Dental Plaque Index, Female, Humans, Male, Dental Plaque prevention & control, Toothpastes therapeutic use
- Abstract
Purpose: This single-center, clinically controlled, double-blinded, randomised, crossover study aimed to evaluate and compare the antibacterial effect, substantivity and patients' acceptance of three toothpaste slurries after a single application on established biofilms observed for 24 h., Materials and Methods: Twenty-four participants started a test cycle after refraining from oral hygiene for 48 h, with a baseline plaque sample measuring biofilm vitality (in %; VF0) using vital fluorescence (VF). They were instructed to rinse for 1 min with either an amine fluoride, stannous chloride (ASC), an herbal (SBC) or a sodium fluoride (SFL) toothpaste prepared as slurries. Every two hours up to 12 and after 24 h, plaque samples were harvested (VF2-VF24%). Plaque-covered areas (PA in %) were evaluated after 24 h using digital photographs. Patients' acceptance was determined by visual analogue scale (VAS) questionnaire., Results: All participants (16 women, 8 men; 27.5 ± 7.9 years) completed all cycles. Two hours after application (VF2), all toothpastes showed a statistically significant reduction in bacterial vitality (p < 0.05), maintained up to 12 h. ASC revealed statistically significantly lower vitality values compared to SBC at VF2, VF4, VF8, VF12 and VF24, and at VF4, VF12 and VF24 compared to SFL (p < 0.05), while SBC and SFL did not differ statistically significantly at any time point. The preferred toothpastes were SFL (18/24 participants) and ASC (15/24 participants)., Conclusions: All toothpastes showed statistically significant anti-plaque effects on established plaque biofilm and a substantivity up to 24 h compared to their baseline, while ASC still presented a statistically significant effect after 12 and 24 h compared to SBC and SFL.
- Published
- 2021
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37. Discrete Survival Model Analysis of Plasmodium falciparum Response to Artemisinin-Based Combination Therapies among Children in Regions of Varying Malaria Transmission in Cameroon.
- Author
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Nji AM, Ali IM, Niba PTN, Marie-Solange E, Heumann C, Froeschl G, and Mbacham WF
- Abstract
The need to monitor changes in parasite clearance following treatment with artemisinin-based combination therapies (ACTs) is important in the containment of drug resistance. This study aimed to model Plasmodium falciparum response to ACTs among children in two different transmission settings (Mutengene and Garoua) in Cameroon. Using the step function, a discrete-time survival model was fitted with all the covariates included that might play a role in parasite clearance. The probability of clearing parasites within 24 h following treatment was 21.6% and 70.3% for younger children aged 6 to 59 months and 29.3% and 59.8% for older children aged 60 to 120 months in Mutengene and Garoua, respectively. After two days of treatment, the conditional probability of clearing parasites given that they were not cleared on day 1 was 76.7% and 96.6% for children aged 6-59 months and 83.1% and 93.5% for children aged 60-120 months in Mutengene and Garoua, respectively. The model demonstrated that the ecological setting, age group and pretreatment serum levels of creatinine and alanine aminotransferase were the main factors that significantly influenced parasite clearance in vivo after administration of ACTs ( p < 0.05). The findings highlight the need for further investigations on host differential response to ACTs in current practice.
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- 2021
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38. Factors associated with length of stay and treatment outcome of Ebola patients treated at an Ebola treatment center in Sierra Leone during the peak period of the West African Ebola outbreak 2013-2016.
- Author
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Kangbai JB, Heumann C, Hoelscher M, Sahr F, and Froeschl G
- Abstract
Background: The World Health Organization (WHO) declared the West Africa Ebola epidemic as a Public Health Emergency of International Concern in August 2014. During the outbreak period, there were calls for the affected countries to construct Ebola treatment centres and reliable diagnostic laboratories closer to areas of transmission in order to improve the quality care of Ebola Virus Disease (EVD) patients. Delay in seeking treatment has been reported to have led to poor treatment outcome of EVD patients. Sierra Leone recorded more than 8000 probable and confirmed cases and more than 4000 EVD -related deaths nation-wide., Methods: In this retrospective study, we investigated the effects of treatment delay, length of symptomatic period, EVD patients' sex, age, occupation, region of residence, and clinical characteristics on the treatment outcome of 205 laboratory-confirmed EVD patients who were admitted at the Kenema Government Hospital Ebola Treatment Center (KGHETC) from 13/09/2014-26/11/2014; i.e. during the peak of 2013-2016 EVD outbreak in Sierra Leone. Specifically also, we determined the factors that were associated with the length of stay for EVD treatment for patients who were discharged alive., Results: Majority (66.3%, n = 205/309) of the 309 suspected EVD patients with medical records at the KGHETC triage during the period under review were tested positive for EVD using reverse-transcriptase-polymerase chain reaction (RT-PCR) and had a definitive treatment outcome. Few (33.7%, n = 104/309) suspected EVD patients were not included in our analysis and were classified thus: 29.1% (n = 90/309) suspect EVD cases with negative RT-PCR results, 4.5% (n = 14/309) suspect cases with non-available RT-PCR result. Of the 205 patients, 99 (48.3%) had a fatal outcome. For EVD patients that survived, we recorded a significant association (- 0.06, 95% Confidence Interval (CI) = - 0.14 - - 0.02, p = 0.004) between the Length of Stay (LOS) and for each kilometer travelled to seek treatment at the KGHETC. However, the association between EVD patients that were low skilled workers (- 5.91, 95% CI = - 24.60 - 12.79, p = 0.73), EVD patients who were children and pupils in junior school (- 0.86, 95% CI = - 12.86 - 11.14, p = 0.73), health seeking delay for EVD patients who resided in Kenema District where the KGHETC was located (- 0.49, 95% CI = - 0.12 - 1.09, p = 0.24), sex (- 1.77, 95% CI = - 8.75 - 5.21, p = 0.50), age (0.21, 95% CI = - 0.36 - 0.77, p = 0.57), referral status (1.21, 95% CI = - 17.67 - 20.09, p = 0.89) and the LOS in surviving patients were not statistically significant., Conclusion: The high LOS for either treatment outcome for EVD patients that resided in the district in which the EVD treatment facility was located compared to those patients from other districts implies that health authorities should consider intensive health education with high priority given to seeking early EVD treatment, and the construction of strategic ETCs as important components in their response strategy., (© 2021. The Author(s).)
- Published
- 2021
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39. Multiple imputation with compatibility for high-dimensional data.
- Author
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Zahid FM, Faisal S, and Heumann C
- Subjects
- Computer Simulation, Models, Statistical, Probability, Sample Size, Software, Data Interpretation, Statistical
- Abstract
Multiple Imputation (MI) is always challenging in high dimensional settings. The imputation model with some selected number of predictors can be incompatible with the analysis model leading to inconsistent and biased estimates. Although compatibility in such cases may not be achieved, but one can obtain consistent and unbiased estimates using a semi-compatible imputation model. We propose to relax the lasso penalty for selecting a large set of variables (at most n). The substantive model that also uses some formal variable selection procedure in high-dimensional structures is then expected to be nested in this imputation model. The resulting imputation model will be semi-compatible with high probability. The likelihood estimates can be unstable and can face the convergence issues as the number of variables becomes nearly as large as the sample size. To address these issues, we further propose to use a ridge penalty for obtaining the posterior distribution of the parameters based on the observed data. The proposed technique is compared with the standard MI software and MI techniques available for high-dimensional data in simulation studies and a real life dataset. Our results exhibit the superiority of the proposed approach to the existing MI approaches while addressing the compatibility issue., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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40. Influence of Probiotics on the Salivary Microflora Oral Streptococci and Their Integration into Oral Biofilm.
- Author
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Arweiler NB, Auschill TM, Heumann C, Hellwig E, and Al-Ahmad A
- Abstract
Probiotics' ability to integrate into dental biofilms is not yet clarified. The aim of this trial was to detect probiotic bacteria from probiotic products in dental biofilm and saliva during and after intake. In this parallel, randomized clinical trial, 39 subjects wore customized appliances to build up intra-oral biofilms (72-h periods). The trial was divided into screening (S) to determine baseline biofilm flora, intervention (I), and wash out (WO). During I (28 days), subjects consumed a product containing (a) Enterococcus faecalis (b) Lactobacillus , or (c) casei , or (c) Lactobacillus rhamnosus GG. Probiotic bacteria and Streptococci spp. were detected in the biofilms and saliva of the 35 subjects that were included in the analysis. During I and WO, the ratio of probiotics in the biofilm was very low compared to total bacterial load, while saliva had slightly but not significantly higher values. No significant changes of probiotic bacteria ( p > 0.05) were found at any visit during I or WO. The proportion of streptococci was significantly reduced ( p < 0.05) during I and even lower in WO, compared to S. Probiotic bacteria could neither integrate nor persist in dental biofilm and saliva but did influence the growth of streptococci in biofilm and saliva.
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- 2020
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41. Severity score for predicting in-facility Ebola treatment outcome.
- Author
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Kangbai JB, Heumann C, Hoelscher M, Sahr F, and Froeschl G
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Disease Outbreaks, Epidemics, Female, Health Facilities, Hemorrhagic Fever, Ebola diagnosis, Hemorrhagic Fever, Ebola mortality, Humans, Infant, Infant, Newborn, Male, Middle Aged, Prognosis, Retrospective Studies, Severity of Illness Index, Sierra Leone epidemiology, Socioeconomic Factors, Treatment Outcome, Young Adult, Hemorrhagic Fever, Ebola therapy, Hospital Mortality, Hospitalization statistics & numerical data
- Abstract
Purpose: Sierra Leone recorded the highest incidence rate for the 2013-2016 West African Ebola outbreak. In this investigation, we used the medical records of Ebola patients with different sociodemographic and clinical features to determine the factors that are associated with Ebola treatment outcome during the 2013-2016 West African Ebola outbreak in Sierra Leone and constructed a predictive in-facility mortality score., Methods: We used the anonymized medical records of 1077 laboratory-confirmed pediatric and adult patients with EVD who received treatment at the 34 Military Hospital and the Police Training School Ebola Treatment Centers in Sierra Leone between the period of June 2014 and April 2015. We later determined the in-facility case fatality rates for Ebola, the odds of dying during Ebola treatment, and later constructed a predictive in-facility mortality score for these patients based on their clinical and sociodemographic characteristics., Results: We constructed a model that partitioned the study population into three mortality risk groups of equal patient numbers, based on risk scoring: low (score ≤ -5), medium (score -4 to 1), and high-risk group (score ≥ 2). The CFR of patients with EVD belonging to the low- (≤-5), medium (-4 to 1), and high- (≥2) risk groups were 0.56%, 9.75%, and 67.41%, respectively., Conclusions: We succeeded in designing an in-facility mortality risk score that reflects EVD clinical severity and can assist in the clinical prioritization of patients with EVD., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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42. Investigating Parallel Analysis in the Context of Missing Data: A Simulation Study Comparing Six Missing Data Methods.
- Author
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Goretzko D, Heumann C, and Bühner M
- Abstract
Exploratory factor analysis is a statistical method commonly used in psychological research to investigate latent variables and to develop questionnaires. Although such self-report questionnaires are prone to missing values, there is not much literature on this topic with regard to exploratory factor analysis-and especially the process of factor retention. Determining the correct number of factors is crucial for the analysis, yet little is known about how to deal with missingness in this process. Therefore, in a simulation study, six missing data methods (an expectation-maximization algorithm, predictive mean matching, Bayesian regression, random forest imputation, complete case analysis, and pairwise complete observations) were compared with respect to the accuracy of the parallel analysis chosen as retention criterion. Data were simulated for correlated and uncorrelated factor structures with two, four, or six factors; 12, 24, or 48 variables; 250, 500, or 1,000 observations and three different missing data mechanisms. Two different procedures combining multiply imputed data sets were tested. The results showed that no missing data method was always superior, yet random forest imputation performed best for the majority of conditions-in particular when parallel analysis was applied to the averaged correlation matrix rather than to each imputed data set separately. Complete case analysis and pairwise complete observations were often inferior to multiple imputation., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2019.)
- Published
- 2020
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43. Sociodemographic and clinical determinants of in-facility case fatality rate for 938 adult Ebola patients treated at Sierra Leone Ebola treatment center.
- Author
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Kangbai JB, Heumann C, Hoelscher M, Sahr F, and Froeschl G
- Subjects
- Adolescent, Adult, Aged, Area Under Curve, Disease Outbreaks, Female, Health Facilities, Hemorrhagic Fever, Ebola epidemiology, Hemorrhagic Fever, Ebola pathology, Hospitalization, Humans, Incidence, Logistic Models, Male, Middle Aged, ROC Curve, Severity of Illness Index, Sierra Leone epidemiology, Survival Analysis, Young Adult, Hemorrhagic Fever, Ebola mortality
- Abstract
Background: The 2013-2016 West Africa Ebola Virus Disease (EVD) outbreak recorded the highest incidence and mortality since the discovery of the virus in Zaire in 1976; with more than 28,000 probable and confirmed EVD cases and 11,000 deaths. Studies relating to previous outbreaks usually involved small sample sizes. In this study we are set to identify those sociodemographic and clinical features that predict in-facility mortality among EVD patients using a large sample size., Methods: We analysed the anonymized medical records of 938 laboratory-confirmed EVD patients 15 years old and above who received treatment at The 34 Military Hospital and The Police Training School EVD Treatment Centers in Sierra Leone in the period June 2014 to April 2015. We used both univariable and multivariable logistic regression to determine the predictors for in-facility mortality of these patients based on their sociodemographic and clinical characteristics., Results: The median age of the EVD cases was 33 years (interquartile range = 25 to 40 years). The majority of the EVD cases were male (59.0%) and had secondary level education (79.3%). We reported a low overall in-facility case fatality rate of 26.4%. The associations between case fatality rates and EVD patients who reported fever, abdominal pain, cough, diarrhoea, vomiting, fatigue, haemorrhage, dysphagia, conjunctival injection, dyspnea, and skin rash at the time of admission were all statistically significant (p < 0.05). Our preferred model with the age group 65 years and above alongside the following clinical symptoms; diarrhoea, vomiting, fatigue, dysphagia, conjunctival injection, dyspnea and cough produced a receiver operating characteristic (ROC) curve with an AUC (area under the curve) value of 0.93., Conclusions: We constructed a simple model that can be optimally used alongside other rapid EVD diagnostic tools to identify EVD in-facility treatment mortality predictors based on the sociodemographic characteristics and clinical symptoms of adult EVD patients. We also reported low EVD cases among patients with secondary and tertiary education. These subpopulations of our patients who are generally informed about the signs and symptoms of EVD, alongside our treatment regimen may have been responsible for our comparatively lower case fatality rate.
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- 2020
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44. Effect of toothpaste containing amine fluoride and stannous chloride on the reduction of dental plaque and gingival inflammation. A randomized controlled 12-week home-use study.
- Author
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Lorenz K, Hoffmann T, Heumann C, and Noack B
- Subjects
- Adult, Amines, Dental Plaque Index, Fluorides, Humans, Inflammation, Tin Compounds, Dental Plaque, Gingivitis, Toothpastes
- Abstract
Objectives: This single-centre, controlled, randomized, double-blinded clinical study in parallel groups was performed to assess the efficacy of an experimental toothpaste on plaque and gingivitis., Methods: In adult subjects with gingivitis, amine fluoride/stannous chloride toothpaste (test) and monofluorophosphate toothpaste (control) were applied twice daily by regular toothbrushing at home. Evaluations of plaque index (PI), gingival index (GI), modified sulcus bleeding index (mSBI) and safety took place at baseline and after 3 and 12 weeks of study product use. After study completion, all subjects received a dental prophylaxis. A descriptive statistical analysis included means and standard deviations. Unpaired t tests compared index reductions between groups at a significance level of 0.05., Results: Intention-to-treat analysis included 240 out of 241 subjects. Baseline mean PI was reduced by 0.87 ± 0.35 in the test group and by 0.65 ± 0.41 in the control group. Within-group differences and between-group differences in index reduction were statistically significant (P < 0.001). Mean GI and mSBI were reduced significantly over time (P < 0.001) with no clinically meaningful differences between groups., Conclusions: Both toothpastes reduced plaque and gingivitis statistically significant and clinically meaningful over 12 weeks. Compared to the control toothpaste, application of the amine fluoride/stannous chloride toothpaste led to a clinically meaningful and more pronounced plaque reduction., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2019
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45. Multiple imputation with sequential penalized regression.
- Author
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Zahid FM and Heumann C
- Subjects
- Computer Simulation, Linear Models, Algorithms, Data Interpretation, Statistical, Software
- Abstract
Missing data is a common issue that can cause problems in estimation and inference in biomedical, epidemiological and social research. Multiple imputation is an increasingly popular approach for handling missing data. In case of a large number of covariates with missing data, existing multiple imputation software packages may not work properly and often produce errors. We propose a multiple imputation algorithm called mispr based on sequential penalized regression models. Each variable with missing values is assumed to have a different distributional form and is imputed with its own imputation model using the ridge penalty. In the case of a large number of predictors with respect to the sample size, the use of a quadratic penalty guarantees unique estimates for the parameters and leads to better predictions than the usual Maximum Likelihood Estimation (MLE), with a good compromise between bias and variance. As a result, the proposed algorithm performs well and provides imputed values that are better even for a large number of covariates with small samples. The results are compared with the existing software packages mice, VIM and Amelia in simulation studies. The missing at random mechanism was the main assumption in the simulation study. The imputation performance of the proposed algorithm is evaluated with mean squared imputation error and mean absolute imputation error. The mean squared error ( β ^ ), parameter estimates with their standard errors and confidence intervals are also computed to compare the performance in the regression context. The proposed algorithm is observed to be a good competitor to the existing algorithms, with smaller mean squared imputation error, mean absolute imputation error and mean squared error. The algorithm's performance becomes considerably better than that of the existing algorithms with increasing number of covariates, especially when the number of predictors is close to or even greater than the sample size. Two real-life datasets are also used to examine the performance of the proposed algorithm using simulations.
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- 2019
- Full Text
- View/download PDF
46. Efficacy of 8% arginine on dentin hypersensitivity: A multicenter clinical trial in 273 patients over 24 weeks.
- Author
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Hirsiger C, Schmidlin PR, Michaelis M, Hirsch C, Attin T, Heumann C, Doméjean S, and Gernhardt CR
- Subjects
- Calcium Carbonate therapeutic use, Humans, Phosphates, Toothpastes, Treatment Outcome, Arginine therapeutic use, Dentin Desensitizing Agents therapeutic use, Dentin Sensitivity drug therapy
- Abstract
Objectives: To assess the efficacy of 8% arginine containing prophylaxis products over 24 weeks in subjects with dentin hypersensitivity (DH)., Methods: 297 patients with established DH (Schiff score 2, 3) in three European study centers were randomly assigned to either 8% arginine and calcium carbonate in-office prophylaxis paste and the respective toothpaste (test group) or fluoride-free prophylaxis paste and sodium monoflourophosphate toothpaste as a negative control group. Air blast (Schiff Score) and tactile (Visual Analog Scale) sensitivity scores were assessed at baseline (BL_0), after single application of the prophylaxis paste (BL_1) and after 4, 8, and 24 weeks of continuous at-home use of the toothpaste., Results: 273 subjects completed the study. Test and control group presented statistically significant percentage reductions (t-test, p < 0.05) in Schiff Score at BL_1 and at 24 weeks relative to BL_0 (difference in %; test group: -23.6, -44.9, control group: -8.8, -32.7). The pooled Schiff Score for the two evaluated teeth yielded a significantly greater alleviation of DH in the test group than in the control group at all evaluation appointments (Ancova, p < 0.05; difference in %: 15.3, 7.4, 10.6, 17.2)., Conclusions: A significant relief of DH was demonstrated after application of the 8% arginine prophylaxis products over 24 weeks compared to a negative control., Clinical Significance: Whilst DH is influencing patients' eating, drinking and tooth brushing habits as well as social life interactions it is important that clinicians are able to offer evidence based immediate and long-lasting treatment methods in order to manage their patients' discomfort., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
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- 2019
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47. Bacterial supernatants elevate glucose-dependent insulin secretion in rat pancreatic INS-1 line and islet β-cells via PI3K/AKT signaling.
- Author
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Ramenzoni LL, Zuellig RA, Hussain A, Lehmann R, Heumann C, Attin T, and Schmidlin PR
- Subjects
- Animals, Bacteria growth & development, Cell Culture Techniques, Insulin Secretion drug effects, Insulinoma drug therapy, Insulinoma metabolism, Islets of Langerhans drug effects, Islets of Langerhans pathology, Male, Phosphatidylinositol 3-Kinases genetics, Proto-Oncogene Proteins c-akt genetics, Rats, Rats, Wistar, Signal Transduction, Sweetening Agents pharmacology, Bacteria metabolism, Glucose pharmacology, Insulin metabolism, Insulinoma pathology, Islets of Langerhans metabolism, Phosphatidylinositol 3-Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Diabetes and periodontitis are considered associated chronic diseases, and hyperinsulinemia in prediabetes has been shown to be present in normoglycemic animals with periodontitis. As periodontal bacterial species are significant sources of endotoxemia and may directly stimulate insulin secretion, we hypothesized that increased bacterial virulence may exert an adverse effect on rat pancreatic β-cell function via PI3K/AKT signaling. INS-1 cells and isolated pancreatic islets were cultured separately with the following supernatants: Streptococcus anginosus, Streptococcus mutans, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis (P.g), and Treponema denticola (T.d). Supernatants were purified from single bacterial cultures and prepared at different dilutions (100 pg/ml, 50 ng/ml, 200 ng/ml, and 500 ng/ml) to challenge INS-1 and islets. Gene expression (IL-1β, TNFα, IL-6, TLR2, TLR4, Ins1, and Ins2) and insulin secretion were measured. The results showed upregulation of gene expression up to 5.5-fold, not only as a result of the different dilutions used, but also due to bacterial virulence (p < 0.05). P.g and T.d supernatants demonstrated an increase in insulin secretion to fivefold at hypo- and hyperglycemia, yet stimulation from hypo- to hyperglycemia stays in the same ratio. Activation of TLR4/PI3K/AKT signaling by supernatants in INS-1 cells resulted in increased IL-1β, TNFα, IL-6 gene expression levels, and AKT phosphorylation, which were abolished by TLR4 and PI3K/AKT signaling inhibitor. We demonstrated that bacterial supernatants derived from gram-negative species increasingly stimulate insulin secretion in β-cells and TLR4 may promote inflammation by activating the PI3K/AKT signaling pathway to induce pro-inflammatory molecules. Bacterial species, depending on their virulence, appear to play a role in the relationship between periodontitis and prediabetes by promoting insulin resistance and β-cell compensatory response.
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- 2019
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48. Epidemiological characteristics, clinical manifestations, and treatment outcome of 139 paediatric Ebola patients treated at a Sierra Leone Ebola treatment center.
- Author
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Kangbai JB, Heumann C, Hoelscher M, Sahr F, and Froeschl G
- Subjects
- Adult, Antiviral Agents administration & dosage, Child, Child, Preschool, Disease Outbreaks, Ebolavirus physiology, Female, Hemorrhagic Fever, Ebola diagnosis, Hemorrhagic Fever, Ebola epidemiology, Hemorrhagic Fever, Ebola virology, Hospitalization, Humans, Logistic Models, Male, Pediatrics statistics & numerical data, Retrospective Studies, Sierra Leone epidemiology, Treatment Outcome, Hemorrhagic Fever, Ebola drug therapy
- Abstract
Background: The West Africa Ebola Virus Disease (EVD) outbreak in 2014-2016 was declared by the World Health Organization (WHO) a public health emergency of international concern. Most of the previous studies done in Sierra Leone relating to the clinical and epidemiological features of EVD during the 2014-2016 West African outbreak focused on adult EVD patients. There have been conflicting reports about the effects of EVD on children during previous outbreaks., Methods: This is an observational retrospective analysis of medical data of all laboratory confirmed paediatric EVD patients below 15 years of age who were admitted at the 34 Military Hospital Ebola Treatment Center (ETC) in Wilberforce, Sierra Leone between June 2014 to April 2015. We analyzed the sociodemographic and clinical characteristics of paediatric EVD cases contained in case report forms that were collected by Ebola surveillance officers and clinicians at the 34 Military Hospital ETC. Both univariate and multivariate logistic regression models were used to determine the sociodemographic and clinical characteristics of paediatric EVD patients that were associated with EVD facility-based mortality., Results: The majority of the paediatric EVD cases in this study were female (56.1%), pupils (51.1%), and 43.2% belonged to the age group between 10 years and below 15 years. The median age of the paediatric EVD cases was 9 years (interquartile range = 4 to 11 years). Adjusting for other covariates in the model, male paediatric EVD patient (AOR = 13.4, 95% CI = [2.07-156-18], p < 0.05), EVD patient with abdominal pain (AOR = 11.0, 95% CI = [1.30-161.81], p < 0.05), vomiting (AOR = 35.7, 95% CI = [3.43-833.73], p < 0.05), signs of conjunctivitis (AOR = 17.4, 95% CI = [1.53-342.21], p < 0.05) and difficulty in breathing (AOR = 23.3, 95% CI = [1.92-713.01], p < 0.05) at the time of admission had increased odds of dying during EVD treatment., Conclusions: We recommend the adoption of case definitions currently in vigour to cater for specific characteristics of paediatric patients. Subgroups that can be identified by applying the model developed in this study may require special attention and intensified care.
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- 2019
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49. Getting pre-exposure prophylaxis to high-risk transgender women: lessons from Detroit, USA.
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Hood JE, Eljallad T, Abad J, Connolly M, Heumann C, Fritz J, Roach M, Lukomski D, and Golden MR
- Subjects
- Adult, Cross-Sectional Studies, Female, Health Services Accessibility, Health Services Needs and Demand, Humans, Michigan, Program Evaluation, Anti-HIV Agents administration & dosage, HIV Infections prevention & control, Pre-Exposure Prophylaxis, Sexually Transmitted Diseases, Viral prevention & control, Transgender Persons
- Abstract
Background Pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention strategy, but it is unclear how best to deliver PrEP to key populations. Drawing upon a cross-sectional survey of transgender women (TW) in Detroit, USA, and experience of a PrEP clinic that serves this population, this manuscript describes the following: (1) the risk profile of Detroit TW; (2) the proportion of TW with at least one PrEP indication; and (3) perceptions of and experiences with PrEP among TW in Detroit., Methods: Between August 2017 and March 2018, 126 TW completed an online PrEP survey. Survey responses were summarised using descriptive statistics and multivariable relative risk regression., Results: Among participants who reported a negative or unknown HIV status (76% of all participants), 56% reported risk behaviour(s) consistent with PrEP indication guidelines, 17% reported currently taking PrEP and another 4% reported discontinued PrEP use. Among participants who met an indication for PrEP but were not currently taking PrEP, 64% indicated that they were not interested in taking PrEP. Approximately 60% of participants who were not currently taking PrEP reported that they would be more likely to take PrEP if it were provided at a clinic that also provided hormone replacement therapy., Conclusions: Although a substantial proportion of TW in our survey were on PrEP, interest in PrEP among high-risk TW who were not taking it was low. Specialised clinical infrastructure that is responsive to the specific needs of TW may be needed to expand PrEP to this oftentimes marginalised and high-risk population.
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- 2018
- Full Text
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50. Risk for cancer among people living with AIDS, 1997-2012: the São Paulo AIDS-cancer linkage study.
- Author
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Tanaka LF, Latorre MRDO, Gutierrez EB, Curado MP, Froeschl G, Heumann C, and Herbinger KH
- Subjects
- Adult, Brazil epidemiology, Case-Control Studies, Female, Follow-Up Studies, Humans, Incidence, Male, Middle Aged, Neoplasms diagnosis, Prognosis, Registries, Risk Factors, Time Factors, Acquired Immunodeficiency Syndrome complications, Neoplasms epidemiology, Neoplasms etiology
- Abstract
Previous studies have reported an increased risk for certain types of cancer in the HIV-infected population. The aim of this study was to assess the risk for cancer in people with AIDS (PWA) in comparison with the general population in São Paulo (Brazil), between 1997 and 2012. A population-based registry linkage study was carried out to assess the risk for cancer, using a standardized incidence ratio (SIR) approach. A total of 480 102 person-years, of which 337 941 (70.4%) person-years were men, were included in the analysis. Around 2074 cancer cases were diagnosed among PWA, of which 51.0% were non-AIDS-defining cancers (NADC). The risk for AIDS-defining cancers and NADC in the male population with AIDS was significantly higher than that in the general population (SIR=27.74 and 1.87, respectively), as it was in the female population with AIDS compared with the general population (SIR=8.71 and 1.44, respectively). Most virus-related NADC occurred at elevated rates among PWA: anal cancer (SIR=33.02 in men and 11.21 in women), liver (SIR=4.35 in men and 4.84 in women), vulva and vagina (SIR=6.78 in women) and Hodgkin lymphoma (SIR=5.84 in men and 2.71 in women). Lung (SIR=2.24 in men and 2.60 in women) and central nervous system (SIR=1.92 in men and 3.48 in women) cancers also occurred at increased rates. Cancer burden among PWA in São Paulo was similar to that described in high-income countries such as the USA and Italy following the introduction of the highly active antiretroviral therapy. As coinfection with oncogenic viruses disproportionally affects this population, virus-related cancers accounted for a great share of excessive cases.
- Published
- 2018
- Full Text
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