Publications

Publications in health services research, clinical studies and evolutionary biology

Potentially inappropriate medication: prevalence, risk of hospitalisation and associated healthcare costs in the general older population of Switzerland

Renato Farcher, Sereina M. Graber, Stefan Boes, Carola A. Huber

Swiss Medical Weekly, Volume 156 No. 4, 2026

This study showed a high PIM prevalence and associated public health burden in terms of hospitalisations and healthcare costs in the general older population of Switzerland. These findings may indicate limited awareness in prescribing PIMs in primary care and the challenge associated with managing conflicting therapeutic recommendations in vulnerable patients. Given the ageing population and rising healthcare costs, the study highlights the urgent need for targeted strategies to reduce PIMs.

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Use of antidepressants before, during, and after pregnancy between 2015 and 2021 in Switzerland: a retrospective analysis of Swiss health care claims data

Alessia Danelli, Carole A. Marxer, Sereina M. Graber, Carola Huber, Simeon J. Zürcher, Alice Panchaud, Daniel Surbek, Christoph R. Meier, Julia Spoendlin

Journal of Affective Disorders, Volume 403, 2026

Depression and anxiety are common during pregnancy, but antidepressant use in Switzerland is not well documented. This analysis of Swiss insurance claims data (2015–2021) showed that 4% of women used antidepressants before pregnancy, but 60% discontinued treatment during pregnancy, with use declining from trimester one to three. Given the potential long-term consequences of untreated maternal depression, these findings highlight a need for careful management of mental health in pregnancy.

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$Post-fracture care and predictors of anti-osteoporotic treatment in Switzerland$

Post-fracture care and predictors of anti-osteoporotic treatment in Switzerland

Judith Everts-Graber, Gernot Schmid, Hans-Jörg Häuselmann, Carola Huber, Sven Streit, Willeke Ravensbergen, Stephan Reichenbach, Britta Maurer, Thomas Lehmann, Rafael Pinedo-Villanueva, Sereina M. Graber

Osteoporosis International, 2026

Osteoporosis-related fractures trigger a dangerous cycle: each fracture raises the risk of the next. This analysis of Swiss insurance claims found that 88% of hip fracture patients and 77% of vertebral fracture patients received no osteoporosis therapy within 6 months. The consequences extend well beyond bone: rehabilitation, nursing home care, and higher mortality follow.

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Mehr Computertomographien – Risiko für Schwangere?

Sabrina M. Stollberg, Sereina M. Graber

Helsana Standpunkt, Nr. 4, 2025

Die Computertomographie (CT) ist ein unverzichtbares Instrument der modernen Medizin. Aber es birgt Risiken, gerade für Frauen im reproduktiven Alter. Eine neue Auswertung von Helsana zeigt, dass bei dieser Gruppe die CT-Anwendungen zunehmen.

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Antibiotika-Verschreibungen: Packungsgrösse spielt eine entscheidende Rolle

Sabrina M. Stollberg, Sereina M. Graber

Helsana Standpunkt, Nr. 1, 2025

Im Jahr 2022 wurden in der Schweiz aufgrund zu grosser Antibiotika-Packungen potentiell rund 2,7 Millionen Tabletten mehr verschrieben als nötig – ein Problem, besonders angesichts von Lieferengpässen und der wachsenden Gefahr von Antibiotikaresistenzen.

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Exposure to potentially teratogenic medications before and during the first trimester of pregnancy compared to women of childbearing age: A retrospective analysis of Swiss claims data (2015–2021)

Carole A. Marxer, Sereina M. Graber, Daniel Surbek, Alice Panchaud, Christoph R. Meier, Julia Spoendlin

Acta Obstetricia et Gynecologica Scandinavica, 104 (2), 2025

This study assessed exposure to potentially teratogenic medications among pregnant women and women of childbearing age in Switzerland using claims data (2015–2021). Results showed that 1.4% of pregnant women were exposed to potential teratogens during the first trimester, with weak teratogens being the most commonly dispensed. Additionally, valproate use during pregnancy decreased following the introduction of a pregnancy prevention program in 2018, suggesting a potential positive impact.

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Antibiotika - Eine Bestandesaufnahme: Wer verschreibt wie viel?

Sereina M. Graber, Sabrina M. Stollberg

Helsana Standpunkt, Nr. 4, 2024

Der verantwortungsvolle Einsatz von Antibiotika ist entscheidend, da ihre übermäßige Verwendung die Entstehung resistenter Bakterien begünstigt. Die vorliegende Studie hat untersucht, wie viele Antibiotika in der ambulanten Versorgung von welchen medizinischen Fachgruppen in der Schweiz verschrieben werden. Die Ergebnisse liefern unerwartete Erkenntnisse.

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Discrepancy between antibiotic pack sizes and guideline recommendations: a real-world analysis based on claims data

Sabrina M. Stollberg, Sereina M. Graber, Andreas Kronenberg, Oliver Senn, Stefan Neuner-Jehle, Catherine Pluess-Suard, Carola A. Huber, Andreas Plate

Infection, 2024

This study assessed the potential mismatch between prescribed antibiotic pack sizes and guideline recommendations, using data from a large Swiss health insurance company. It found that 31.6% of prescriptions were potentially non-conform, with 2.7 million excess tablets overprescribed in 2022. The results highlight the need for alternatives, such as exact pill dispensing, to reduce antibiotic resistance and waste caused by inappropriate pack sizes..

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Are integrated care models associated with improved drug safety in Swiss primary care? an observational analysis using healthcare claims data

Renato Farcher, Sereina M. Graber, Stefan Boes, Carola A. Huber

PLOS ONE, 19 (9), 2024

This observational study investigates drug safety in integrated care models (ICM) in comparison to standard care insurance models (SCM) in Swiss primary care. The study found that ICM patients had significantly lower odds of receiving inappropriate prescriptions, such as proton pump inhibitors or opioids, compared to SCM patients. These findings suggest that patients may benefit most from ICMs with a high degree of coordination or gatekeeping, ultimately improving patients’ drug safety and reducing the risk of adverse events.

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Prescriber-level surveillance of outpatient antimicrobial consumption to enable targeted antimicrobial stewardship: a nationwide observational study, Switzerland, 2015 to 2022

Sereina M. Graber, Sabrina M. Stollberg, Catherine Plüss-Suard, Carola A. Huber, Andreas Kronenberg, Oliver Senn, Stefan Neuner-Jehle, Andreas Plate

Eurosurveillance, 29 (37), 2024

This study analyzed antibiotic consumption (AMC) in the outpatient setting in Switzerland, focusing on the contributions of different prescriber groups. Overall, antibiotic prescriptions declined by 12.4% from 2015 to 2022. With ca 66% in 2022, the largest prescriber group of primary care physicians contributed less than expected, whereas hospital-affiliated outpatient care emerged as an important prescriber group with ca 20%. This type of surveillance builds the basis for sharing information with specific groups of physicians, which can help to improve the responsible use of antibiotics and address the rise of resistance.

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Dispensed drugs during pregnancy in outpatient care between 2015 and 2021 in Switzerland: a retrospective analysis of Swiss healthcare claims data

Carole A. Marxer, Sereina M. Graber, Daniel Surbek, Alice Panchaud, Christoph R. Meier, Julia Spoendlin

Swiss Medical Weekly, 154 (8), 2024

This study assessed the use of prescribed drugs during pregnancy in Switzerland between 2015 and 2021 using data from the Helsana claims database. It found that almost 90% of pregnant women claimed at least one drug (excluding vitamins and vaccines), with one third claiming at least five distinct drugs during pregnancy. The study highlights that while most drugs used during pregnancy are well-researched and considered safe, the high drug burden in pregnant women emphasizes the need for robust evidence on the benefit-risk profile of medications taken during this vulnerable period.

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Real-world treatment patterns and medical costs of prostate cancer patients in Switzerland - A claims data analysis

Michael Stucki, Stephanie Dosch, Markus Gnädinger, Sereina M. Graber, Carola A. Huber, Golda Lenzin, Räto T. Strebel, Daniel R. Zwahlen, Aurelius Omlin, Simon Wieser

European Journal of Cancer, 204(114072), 2024

This study examined healthcare utilization, treatment patterns, and medical costs for prostate cancer (PC) patients in Switzerland from 2014 to 2018 using insurance claims data. It found that androgen deprivation therapy (ADT) was the most common treatment, with 9.5% of patients receiving combination therapy with docetaxel, the most frequently used chemotherapy. Total medical costs for PC in 2018 were CHF 347 million, with treatment for metastatic PC accounting for about two-thirds of the total expenditure.

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Helsana-Report:
Versorgung - Qualitätswettbewerb als zentraler Erfolgsfaktor

Andrea Bischof, Renato Farcher, Sereina M. Graber

Helsana Versorgungsreport, 2023

Der Helsana-Versorgungsreport analysiert das Schweizer Gesundheitssystem mit Fokus auf Versorgungsqualität, insbesondere in den Bereichen Prävention, chronische Krankheiten und Medikamentensicherheit. Der Bericht hebt hervor, dass mehr Transparenz und der gezielte Einsatz von Krankenversicherungsdaten dazu beitragen können, Fehlversorgung und Versorgungslücken zu erkennen, wodurch sowohl für Versicherte als auch für das gesamte Gesundheitssystem ein erheblicher Mehrwert geschaffen werden kann.

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Does the implementation of an incentive scheme increase adherence to diabetes guidelines? A retrospective cohort study of managed care enrollees

Renato Farcher, Sereina M. Graber, Nicole Thüring, Eva Blozik, Carola A. Huber

BMC Health Services Research, 23, 2023

This study evaluated the impact of a new incentive scheme introduced in 2018 on adherence to guidelines for diabetes care in Swiss managed care models. The analysis of 6,273 diabetic patients showed moderate but consistent improvements in guideline adherence across several performance measures, with the odds of receiving specific tests increasing by 18% to 58% after the incentive's implementation. The findings suggest that such incentive schemes, which promote transparency in performance, may enhance the quality of care for diabetes patients.

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«Dear Doctor»: Kommen Sicherheitswarnungen an?

Sabrina M. Stollberg, Sereina M. Graber

Helsana Standpunkt, Nr. 1 (Februar), 12-13, 2023

Die Swissmedic kann bei neuen Sicherheitsbedenken zu Medikamenten Hersteller dazu anweisen, sogenannte “Direct Healthcare Professional Communications” (DHPC) an Ärzte zu versenden, um wichtige Informationen weiterzugeben. Eine Auswertung von Helsana-Daten für zwei DHPCs zu Fluorchinolonen (Antibiotika) und Valproat (Epilepsiemedikament) zeigt einen signifikanten Rückgang der Verschreibungen nach Versand der Mitteilungen. Trotz des Rückgangs lässt sich jedoch kein direkter kausaler Zusammenhang ableiten. Die Kurzanalyse regt zur Diskussion über die Optimierung von Sicherheitswarnungen an.

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Parental provisioning drives brain size in birds

Michael Griesser, Szymon M. Drobniak, Sereina M. Graber, Carel P. van Schaik

PNAS Proceedings of the National Academy of Sciences, 120(2), 2023

Large brains, while seemingly advantageous due to cognitive adaptations, are energetically costly and may have limited the evolution of larger brain size in many species. In this comparative analysis of 1,176 bird species, various measures of parental provisioning were found to strongly predict relative brain size, indicating that parental care may be a strategy to overcome the energetic limitations of brain growth.

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The economics of brain size evolution in vertebrates

Sandra A. Heldstab, Karin Isler, Sereina M. Graber, Carel P. van Schaik

Current Biology, 32(12), 697-708, 2022

Across the animal kingdom, brain size varies remarkably. This review summarizes how an increasing number of studies show that to fully comprehend brain size evolution and the large variation in brain size across lineages, it is important to look at the economics of brains, including the different pathways through which the high energetic costs of brains can be offset.

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Evidence-based indicators for the measurement of quality of primary care using health insurance claims data in Switzerland: update of the SQUIPRICA working group

Eva Blozik, Renato Farcher, Sereina M. Graber, Carola A. Huber and Swiss Quality Indicator for Primary Care (SQIPRICA) Working Group

BMC Health Services Research, 22(628), 2022

This study presents an update to the Swiss Quality Indicators for Primary Care (SQIPRICA) working group’s framework. It reports on the addition of nine new quality indicators (QI) covering general efficiency, diagnostic measures, geriatric care, osteoarthritis, and drug safety. These indicators, based on health insurance claims, aim to provide a better evaluation of primary care quality in Switzerland.

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Does hospital volume affect outcomes after abdominal cancer surgery: an analysis of Swiss health insurance claims data

Kevin Wirth, Markus Näpflin, Sereina M. Graber, Eva Blozik

BMC Health Services Research, 22(262), 2022

The study explores the relationship between hospital volume and outcomes for abdominal cancer surgeries in Switzerland. Analyzing health insurance claims data, the research found no significant correlation between higher hospital volumes and improved outcomes. Even though a positive “routine effect” cannot be excluded, the results suggest that even hospitals with low volumes are able to achieve comparable treatment outcomes to larger hospitals.

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Immer weniger Hausbesuche trotz zunehmendem Bedarf

Carola A. Huber, Sereina M. Graber

Helsana Standpunkt, Nr. 1 (Februar), 14-15, 2022

Hausbesuche von HausärztInnen sind in der Schweiz ein wichtiger Bestandteil der Versorgung, besonders für ältere und gebrechliche PatientInnen, deren Bedarf aufgrund der demografischen Entwicklung steigt. Trotz dieses wachsenden Bedarfs ist die Anzahl der Hausbesuche zwischen 2014 und 2018 leicht rückläufig, was auf Faktoren wie Zeitmangel, unzureichende Vergütung und telemedizinische Alternativen zurückzuführen ist. Die Resultate aus einer aktuellen Studie deuten auf eine potenzielle Versorgungslücke hin, die möglicherweise durch zusätzliches Gesundheitspersonal oder bessere Vergütungsmodelle geschlossen werden könnte.

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Use of Prescribed Drugs to Treat Chronic Diseases during Pregnancy in Outpatient Care in Switzerland between 2014 and 2018: Descriptive Analysis of Swiss Health Care Claims Data

Eva Gerbier, Sereina M. Graber, Marlene Rauch, Carole Marxer, Christoph Meier, David Baud, U. Winterfeld, Eva Blozik, Daniel Surbek, Julia Spoendlin, Alice Panchaud

International Journal of Environmental Research and Public Health, 19(3), 2022

This study evaluated the use of drugs to treat chronic diseases during pregnancy in Switzerland using healthcare claims data from 2014 to 2018. Drugs were claimed in 22% of pregnancies, with levothyroxine (6.6%) and antihypertensives (5.3%) being the most frequently prescribed. Patterns of drug claims were in line with treatment recommendations, but relatively rare events of in utero exposure to teratogenic drugs may have had severe implications for those involved.

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Use of drugs to treat symptoms and acute conditions during pregnancy in outpatient care in Switzerland between 2014 and 2018: analysis of Swiss healthcare claims data

Eva Gerbier, Sereina M. Graber, Marlene Rauch, Carole A. Marxer, Christoph R. Meier, David Baud, UrsulaWinterfel, Eva Blozik, Daniel Surbek, Julia Spoendlind, Alice Panchaud

Swiss Medical Weekly, 151(4748), 2021

This study analyzed the use of prescribed drugs during pregnancy in outpatient care in Switzerland from 2014 to 2018, focusing on treatments for pain, infections, gastrointestinal issues, and nausea. Paracetamol was the most commonly claimed analgesic (30.3% of pregnancies), antibiotics were dispensed in 26.3% of cases. Proton-pump-inhibitors and anti-nausea drugs were both claimed in around 16% of all pregnancies. While drug use largely followed treatment guidelines, exposure to potentially harmful drugs was minimal, though the lack of diagnosis data made it difficult to assess if their use was clinically justified.

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Time trends in general practitioners' home visits for older patients: a retrospective cross-sectional study from Switzerland

Stefan Neuner-Jehle, Sereina M. Graber, Ellen Keizer, Carola A. Huber, Eva Blozik, Thomas Rosemann, Oliver Senn

Swiss Medical Weekly, 151(2728), 2021

This study investigated the time trend of GP home visits to older patients from 2014 to 2018 in Switzerland, and its associations with patient characteristics including healthcare utilisation and living situation. The results revealed increased health care utilisation, higher morbidity and mortality in patients receiving GP home visits, and an ongoing decline of GP home visits over the past years, which has a potentially negative impact on the quality of care for older and frail patients.

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Use of valproate in pregnancy and in women of childbearing age between 2014 and 2018 in Switzerland: a retrospective analysis of Swiss healthcare claims data

Julia Spoendlin, Eva Blozik, Sereina M. Graber, Marlene Rauch, Carole A. Marxer, Stephan Rüegg, Christoph Meier, Ursula Winterfeld, Alice Panchaud

Swiss Medical Weekly, 151(0102), 2021

This retrospective descriptive analysis examines the use of antiseizure drugs, particularly valproate, in women of childbearing age and during pregnancy in Switzerland. The prevalence of exposure to valproate during pregnancy was comparable to Denmark and lower than in other European countries. Despite decreasing exposure prevalence, the use of valproate in women of childbearing age in Switzerland seems higher than the actual clinical need.

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Comparing Two Imaging Methods for Follow-Up of Lung Cancer Treatment: A Randomized Pilot Study

Franco Gambazzi, Lukas D. Frey, Matthias Bruehlmeier, Wolf-Dieter Janthur, Sereina M. Graber, Juerg Heuberger, Oliver S. Springer, Roland Zweifel, Bettina Boerner, Gabrielo M. Tini, Sarosh Irani

The Annals of Thoracic Surgery, 107(2), 430-435, 2019

This pilot study compared the effectiveness of PET-CT and contrast-enhanced CT (CE-CT) for detecting lung cancer recurrence during post-curative treatment surveillance. The results showed no significant difference between the two imaging methods in identifying cancer recurrence. Both methods demonstrated similar sensitivity and specificity, suggesting that CE-CT remains a reliable and cost-effective option for follow-up in lung cancer patients.

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Geographical Origin, Delayed Implantation, and Induced Ovulation Explain Reproductive Seasonality in the Carnivora

Sandra A. Heldstab, Dennis W. H. Müller, Sereina M. Graber, Laurie Bingaman Lackey, Eberhard Rensch, Jean-Michel Hatt, Philipp Zerbe, Marcus Clauss

Journal of Biological Rhythms, 33(4), 2018

This study examined reproductive seasonality in 114 species of Carnivora, using data from captive populations. Latitude of origin, delayed implantation, and induced ovulation were found to influence the timing and length of the reproductive season. The findings suggest that species adapt their reproductive cycles to environmental conditions.

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Curiosity boosts orang-utan problem-solving ability

Laura A. Damerius, Sereina M. Graber, Erik P. Willems, Carel P. van Schaik

Animal Behaviour, 134, 57-70, 2017

This study investigated phenotypic plasticity of 61 Bornean and Sumatran orang-utans to gain insight into how rearing history shapes problem-solving approaches. The findings suggest that previous human care and social housing with other orangutans fostered curiosity, and that curiosity is the strongest predictor of problem-solving performance. However, curiosity is rare in wild orangutans, suggesting it may be an artefact of captivity. The origin of curiosity in our own lineage may have been an important contributor to the rapid rise in the complexity of our ancestors’ material culture.

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Significant improvement of olfactory performance in sleep apnea patients after three months of nasal CPAP therapy – Observational study and randomized trial

Bettina Boerner, Gabrielo M. Tini, Patrick Fachinger, Sereina M. Graber, Sarosh Irani

PLoS ONE, 2017

The study assessed olfactory performance in 35 patients with moderate to severe obstructive sleep apnea (OSA) before and after three months of therapy continuous positive airway pressure with nasal masks (nCPAP). Results showed a significant improvement in the sense of smell in patients adhering to the therapy. This suggests that CPAP therapy not only treats sleep apnea but also improves olfaction, enhancing patients' quality of life.

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The Ecology of Social Learning in Animals and its Link with Intelligence

Carel van Schaik, Sereina M. Graber, Caroline Schuppli, Judith Burkart

The Spanish Journal of Psychology, 19, 2017

This review highlights the importance of social learning in the development of skills among birds and mammals, supporting the cultural intelligence hypothesis, which links social learning abilities to the evolution of intelligence. The hypothesis suggests that species with stronger social learning abilities also develop greater individual learning capacity, making intelligence closely tied to cultural processes. The study proposes a social learning spectrum to classify different types of social learning, which, once validated, could help assess the cognitive demands of social learning in various species.

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Life history, cognition and the evolution of complex foraging niches

Caroline Schuppli, Sereina M. Graber, Karin Isler, Carel P. van Schaik

Journal of Human Evolution, 92, 91-100, 2016

This research explored the relationship between life history traits, cognitive abilities, and foraging niche complexity in mammals, particularly primates and carnivorans. The study found that slow development and extended parental care are key factors enabling species to thrive in complex niches. In primates only, complex foraging is linked to enhanced cognitive abilities, supporting theories on ecological factors and the brain size evolution.

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Elevated Matrix Metalloproteinase Levels in Bronchi Infected with Periodontopathogenic Bacteria

Luca Bernasconi, Liza L. Ramenzoni, Ahmed Al-Majid, Gabrielo M. Tini, Sereina M. Graber, Patrick R. Schmidlin, Sarosh Irani

PLoS ONE, 2015

This study explored whether bronchial infections with periodontopathogenic bacteria are linked to elevated inflammatory markers in the lungs. It found that Treponema denticola was associated with increased levels of certain Matrix Metalloproteinases (MMP9 and MMP12) in bronchial fluid, while smoking was independently linked to higher levels of aMMP8 and MMP9. However, other inflammatory markers like interleukins and tumor necrosis factor alpha were unaffected by the presence of these bacteria.

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Uptake of ferromagnetic carbon-encapsulated metal nanoparticles in endothelial cells: Influence of shear stress and endothelial activation

Melanie Jaboson, Birgit Roth Zgraggen, Sereina M. Graber, Christoph M. Schumacher, Wendelin J. Stark, Claudia Dumrese, Jose Maria Mateos, Caroline Aemisegger, Urs Ziegler, Martin Urner, Inge K. Herrmann, Beatrice Beck-Schimmer

Nanomedicine, 10(24), 3537-3546, 2015

This study investigated the uptake of magnetic nanoparticles in endothelial cells under varying conditions of shear stress and endothelial activation. It found that even moderate shear stress reduced nanoparticle uptake, and that inflamed endothelial cells showed higher particle absorption. These findings underscore the importance of considering physiological conditions in designing nanoparticle-based drug delivery systems.

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Late Post-Conditioning with Sevoflurane after Cardiac Surgery - Are Surrogate Markers Associated with Clinical Outcome?

John M. Bonvini, Beatrice Beck-Schimmer, Sonja J. Kuhn, Sereina M. Graber, Thomas A. Neff, Martin Schläpfer

PLoS ONE, 2015

The study evaluated the long-term outcomes of 94 patients who underwent late post-conditioning with sevoflurane after cardiac surgery. While no significant difference was observed in cardiac or non-cardiac events between the sevoflurane and propofol groups, patients treated with sevoflurane required fewer therapeutic interventions and hospital readmissions, if they experienced an event.

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Shared microbiome in gums and the lung in an outpatient population

Patrick R. Schmidlin, Patrick Fachinger, Gabrielo Tini, Sereina M. Graber, Burkhardt Seifert, Sylke Dombrowa, Sarosh Irani

The Journal of Infection, 70(3), 255-263, 2015

This study investigated the simultaneous occurrence of periopathogenic bacteria in the lungs and gums, and the impact of periodontitis. The results suggest that the agreement between periodontal and bronchial microbiome is more distinct for periopathogens than for less pathogenic species. And further, that periodontitis itself represents a risk factor for pulmonary colonization with certain periopathogens.

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Impact of intraoperative fluid administration on outcome in patients undergoing robotic-assisted laparoscopic prostatectomy – a retrospective analysis

Tobias Piegeler, Pamela Dreessen, Sereina M. Graber, Sarah R. Haile, Daniel M. Schmid, Beatrice Beck-Schimmer

BMC Anesthesiology, 14(61), 2014

This study retrospectively analyzed 182 patients undergoing robotic-assisted laparoscopic prostatectomy (RALP) to assess the effects of intraoperative fluid management on perioperative outcomes. Results suggest that a more restrictive fluid management strategy may reduce the risk of complications, and shorten the length of hospitalization.

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