S K Arn

Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zuerich, Zuerich 8092, Switzerland.

31 publications 1994 – 2026 ORCID

What does S K Arn research?

S K Arn studies the thymus, an important organ in the immune system responsible for developing T-cells, which help protect the body against infections. As people age, the thymus shrinks, which can hinder the ability to accept transplanted organs without rejection. For this reason, Arn investigates the impact of an LHRH agonist, a type of hormone-blocking drug, on reversing the shrinkage of the thymus in older miniature swine. The research aims to enhance transplant protocols and improve acceptance rates in older patients who receive organ transplants.

Key findings

  • The LHRH agonist successfully rejuvenated the aging thymus in miniature pigs, potentially allowing for better transplant tolerance.
  • This study indicates that manipulating hormone levels can enhance thymus function in older individuals.
  • Reversal of thymic involution could be key in extending transplant acceptance protocols to older patients.

Frequently asked questions

Does Dr. Arn study aging and the thymus?
Yes, Dr. Arn specifically studies how the aging process affects the thymus and its role in organ transplantation.
What treatments has Dr. Arn researched?
Dr. Arn has researched the use of an LHRH agonist to reverse thymic shrinkage in older patients.
Is Dr. Arn's work relevant to older transplant patients?
Yes, their research is highly relevant as it explores ways to improve organ transplant acceptance in older individuals.

Publications in plain English

Temperature Dependence of Poly(3-hydroxybutyrate--3-hydroxyhexanoate) Biodegradation in Agricultural Soils.

2026

Environmental science & technology

Laszakovits JR, Arn S, Kägi R, Liechti S, Wille F +2 more

Plain English
This study looked at how temperature affects the breakdown of a type of biodegradable plastic used in farming soils. Researchers found that as temperatures increased from 5 to 35 degrees Celsius, the breakdown of the plastic sped up, with the rate of biodegradation increasing by 2 to 5 times for every 10 degrees rise in temperature. Understanding this relationship helps predict how these materials will decompose in real farming situations, which is important for reducing plastic waste. Who this helps: This helps farmers and manufacturers of biodegradable plastics.

PubMed

An Analytical Workflow to Quantify Biodegradable Polyesters in Soils and Its Application to Incubation Experiments.

2025

Environmental science & technology

Cerri M, Wille F, Arn S, Bucheli TD, Widmer F +4 more

Plain English
This research focused on how to effectively measure and track biodegradable plastics in soil, specifically eight types of biodegradable polyesters and one non-biodegradable one. The study found a new method to analyze these plastics, showing that poly(butylene adipate-terephthalate) and polylactic acid could be monitored as they broke down in different agricultural soils. This is important because understanding how these biodegradable materials behave in the environment helps us find better alternatives to traditional plastics. Who this helps: This helps researchers and environmental scientists looking to reduce plastic waste and improve soil health.

PubMed

The electrostatic charge on exuded liquid drops.

2025

Soft matter

Arn S, Illing P, Harper JM, Burton JC

Plain English
This study examined how water droplets develop an electric charge as they fall through the air. Researchers found that each droplet carried an average negative charge of about -5 picocoulombs, and this charge did not change based on how the drops were released or the materials used in the experiment. The findings reveal that the process by which water gains an electric charge is more complicated than previously thought, which could have implications for various fields, from technology to environmental science. Who this helps: This helps scientists and engineers working on applications in material science and environmental research.

PubMed

The metabolic cost of breathing for exercise ventilations: effects of age and sex.

2024

Journal of applied physiology (Bethesda, Md. : 1985)

Kipp S, Arn SR, Leahy MG, Guenette JA, Sheel AW

Plain English
This study looked at how age and sex affect the energy cost of breathing during exercise. Researchers tested 40 healthy people, comparing young males and females (around 24 years old) with older males and females (around 63 years old). They found that younger females used 12.7% of their peak oxygen to breathe at peak exertion, while younger males used 10.7%. Older individuals, both males and females, had a higher breathing cost compared to their younger counterparts, with older males using 6.6% and older females using 6.9% at moderate intensities. Who this helps: This information benefits patients, particularly older adults and female athletes, by highlighting how their respiratory efficiency changes with age.

PubMed

Intra-bone bone marrow transplantation from hCD47 transgenic pigs to baboons prolongs chimerism to >60 days and promotes increased porcine lung transplant survival.

2020

Xenotransplantation

Watanabe H, Ariyoshi Y, Pomposelli T, Takeuchi K, Ekanayake-Alper DK +9 more

Plain English
This study looked at how using bone marrow from specially engineered pigs could improve the survival of lung transplants in baboons. The researchers found that using a type of pig that produces a human protein (hCD47) helped baboons keep foreign pig cells in their bodies for more than 60 days, leading to lung transplants lasting up to 14 days, compared to only 1-4 days without this intervention. This research is important because it could lead to better outcomes for patients needing organ transplants from pigs, addressing the shortage of human donors. Who this helps: This helps patients who need organ transplants and may benefit from xenotransplantation.

PubMed

Contextual variability and exemplar strength in phonotactic learning.

2018

Journal of experimental psychology. Learning, memory, and cognition

Denby T, Schecter J, Arn S, Dimov S, Goldrick M

Plain English
This study examined how people learn the rules for combining speech sounds, looking specifically at two factors: contextual variability (how many different situations a sound pattern appears in) and exemplar strength (how often a pattern is used). The researchers found that when sound patterns had more contextual variability, learners were better at recognizing the rules, even if those patterns were used less often. Overall, the study shows that exposure to varied examples helps people understand language patterns more effectively. Who this helps: This helps language learners and educators in understanding how exposure to diverse language examples can improve learning outcomes.

PubMed

GalT-KO pig lungs are highly susceptible to acute vascular rejection in baboons, which may be mitigated by transgenic expression of hCD47 on porcine blood vessels.

2018

Xenotransplantation

Watanabe H, Sahara H, Nomura S, Tanabe T, Ekanayake-Alper DK +14 more

Plain English
This study explored the use of genetically modified pig lungs in baboons to see if they could survive longer after being transplanted. The researchers found that pig lungs without specific genetic modifications were quickly rejected, surviving only about 25 to 48 hours, while those with a particular modification (expression of human protein hCD47) lasted longer—one lung even remained healthy for over 10 days. This is significant as it shows a way to improve the success of pig lung transplants, which could help advance the future of organ transplantation from animals to humans. Who this helps: This benefits patients in need of lung transplants.

PubMed

Evidence for a gene controlling the induction of transplantation tolerance.

2014

American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons

Lee PW, Hanekamp JS, Villani V, Vagefi PA, Cina RA +5 more

Plain English
Researchers studied the genetic factors affecting how miniature pigs accept kidney transplants. They found that, after a standard treatment, three out of five pigs rejected their transplants, which was unexpected because most pigs accepted their kidneys after similar treatment. The team believes that this rejection was linked to a specific gene in these pigs that made them unable to properly accept the transplant, and understanding this gene could help predict organ transplant success in humans. Who this helps: This research benefits patients undergoing organ transplants by potentially improving their chances of acceptance and minimizing rejection.

PubMed

Reversal of age-related thymic involution by an LHRH agonist in miniature swine.

2010

Transplant immunology

Hirakata A, Okumi M, Griesemer AD, Shimizu A, Nobori S +6 more

Plain English
The thymus shrinks with age, which is a barrier to inducing transplant tolerance using thymus-based protocols in older animals. This study tested whether an LHRH agonist—a hormone-blocking drug—could reverse thymic shrinkage in miniature pigs. The drug successfully rejuvenated the aging thymus, raising the possibility of extending tolerance induction protocols to older transplant recipients.

PubMed

Cytoplasmic inheritance of transplantation antigens in animals produced by nuclear transfer.

2009

Transplantation

Hanekamp JS, Okumi M, Tena A, Arn S, Yamada K +1 more

Plain English
This study looked at how mitochondrial DNA (mtDNA) from female pigs can affect the success of kidney transplants between animals that are genetically similar but have different maternal genetic backgrounds. Researchers found that when they transplanted kidneys from inbred pigs with a specific mtDNA into pigs with outbred mtDNA, the kidneys were rejected within 2 weeks. However, the opposite transplant was accepted for over 30 days, showing that mtDNA differences can significantly impact transplant acceptance. This information is important because it helps us understand how maternal genetic factors can influence organ transplant success. Who this helps: This helps researchers and doctors working on organ transplants.

PubMed

A VEGF-A splice variant defective for heparan sulfate and neuropilin-1 binding shows attenuated signaling through VEGFR-2.

2006

Cellular and molecular life sciences : CMLS

Cébe Suarez S, Pieren M, Cariolato L, Arn S, Hoffmann U +4 more

Plain English
This study looked at a specific variant of a protein called VEGF-A(165)b, which is important for the growth of blood vessels. Researchers found that this variant works much less effectively than the regular version, VEGF-A(165), activating a key receptor involved in blood vessel formation only weakly and briefly. This matters because understanding how different VEGF variants function can help in developing treatments for conditions related to blood vessel growth, such as cancer or cardiovascular diseases. Who this helps: Patients with conditions needing improved blood vessel growth regulation.

PubMed

Early weaning of piglets fails to exclude porcine lymphotropic herpesvirus.

2005

Xenotransplantation

Mueller NJ, Kuwaki K, Knosalla C, Dor FJ, Gollackner B +5 more

Plain English
Researchers studied whether early weaning of piglets could reduce the risk of transmitting a herpesvirus (PLHV-1) when using pigs for organ transplants in other species. They found that while early weaning was successful in eliminating another virus (PCMV), it did not prevent the presence of PLHV-1 in the pigs. This is important because PLHV-1 could lead to complications in transplant procedures, so new methods are needed to eliminate it from pigs used in xenotransplantation. Who this helps: This helps researchers and medical professionals involved in organ transplant procedures using pigs.

PubMed

Genotyping of porcine endogenous retroviruses from a family of miniature swine.

2004

Journal of virology

Quinn G, Wood J, Suling K, Arn S, Sachs DH +2 more

Plain English
This study looked at a special group of miniature pigs to understand why some produce a type of retrovirus (PERV) that can affect humans while others do not. Researchers found specific genetic markers in the blood of pigs that create the human-affecting virus, noting that these markers were unique to a family of pigs that could generate this virus. This discovery helps clarify the genetic traits linked to animal viruses that could potentially impact human health. Who this helps: This benefits researchers and medical scientists studying animal-to-human virus transmission.

PubMed

Identification of exogenous forms of human-tropic porcine endogenous retrovirus in miniature Swine.

2004

Journal of virology

Wood JC, Quinn G, Suling KM, Oldmixon BA, Van Tine BA +9 more

Plain English
This study looked at a type of virus found in miniature pigs that can potentially infect humans during animal-to-human transplants. Researchers found that some miniature pigs carry a form of this virus that is easily transmitted to human cells, while other pigs do not transmit the virus at all. Notably, they discovered that removing pigs that can spread this virus would likely make transplants from these animals safer for humans. Who this helps: This research helps patients who may receive transplants from miniature pigs, as well as doctors involved in these procedures.

PubMed

Production of alpha-1,3-galactosyltransferase null pigs by means of nuclear transfer with fibroblasts bearing loss of heterozygosity mutations.

2004

Proceedings of the National Academy of Sciences of the United States of America

Kolber-Simonds D, Lai L, Watt SR, Denaro M, Arn S +16 more

Plain English
Researchers studied how to create genetically modified pigs that lack a specific sugar on their cell surfaces, which can cause the body to reject pig organs. They found a high rate of success in producing these modified pigs using certain cells, resulting in healthy piglets that do not have this sugar. This is important because it could make pig organs more acceptable for transplantation into humans, reducing the chances of organ rejection. Who this helps: This helps patients in need of organ transplants.

PubMed

Tolerance to solid organ transplants through transfer of MHC class II genes.

2001

The Journal of clinical investigation

Sonntag KC, Emery DW, Yasumoto A, Haller G, Germana S +7 more

Plain English
This study looked at how transferring specific genes related to the immune system (MHC class II genes) into the bone marrow of animals can help their bodies accept kidney transplants without needing long-term anti-rejection medications. The researchers found that this gene therapy method allowed the transplanted kidneys to survive longer, with some lasting significantly longer when combined with a brief treatment of cyclosporine A. This is important because it could lead to better transplant outcomes and less reliance on immunosuppressive drugs, which can have serious side effects. Who this helps: This benefits kidney transplant patients and their doctors by improving transplant success and reducing medication side effects.

PubMed

Tolerance to musculoskeletal allografts with transient lymphocyte chimerism in miniature swine.

2001

Transplantation

Bourget JL, Mathes DW, Nielsen GP, Randolph MA, Tanabe YN +5 more

Plain English
This study looked at how miniature pigs can accept transplanted bone and muscle tissue from other pigs without needing long-term medication to suppress their immune system. Researchers found that while all the pigs showed a short-term immune response, only those treated with the drug cyclosporine maintained acceptance of the grafts for more than 100 days, compared to those without the drug who rejected their grafts within about 6-9 weeks. Understanding how to create lasting acceptance of transplanted tissues without ongoing medications is important because it can improve outcomes for patients needing similar procedures. Who this helps: This helps patients requiring musculoskeletal transplants by reducing the risks associated with long-term medication.

PubMed

An allelic non-histocompatibility antigen with wide tissue distribution as a marker for chimerism in pigs.

1999

Tissue antigens

Fuchimoto Y, Huang C, Shimizu A, Seebach J, Arn S +1 more

Plain English
This study looked at a specific protein on the surface of pig cells, called PAA, to see if it could help researchers understand how well transplanted organs accept in miniature pigs. They discovered that a certain antibody (1038H-10-9) can identify this antigen across various pig tissues, but it does not trigger immune responses that lead to organ rejection. This finding is important because it provides a new tool for studying how transplanted organs integrate and function in pigs, which can help improve transplantation techniques. Who this helps: This benefits researchers and veterinary doctors working on transplantation in pigs.

PubMed

Lack of variation in alphaGal expression on lymphocytes in miniature swine of different genotypes.

1999

Xenotransplantation

Chae SJ, Kramer AD, Zhao Y, Arn S, Cooper DK +1 more

Plain English
The study looked at how different genetic types of small pigs express a sugar molecule called alphaGal, which is important for organ transplantation to humans. The researchers found that there wasn't much difference in alphaGal levels across different pig genotypes, even though variation was seen over time in the same pig. This is significant because identifying pigs with lower alphaGal levels could help improve the safety of using pig organs for human transplants. Who this helps: This research benefits patients needing organ transplants and doctors involved in xenotransplantation.

PubMed

Overview of the Second International Workshop to define swine cluster of differentiation (CD) antigens.

1998

Veterinary immunology and immunopathology

Saalmüller A, Pauly T, Lunney JK, Boyd P, Aasted B +20 more

Plain English
This research focused on improving how scientists classify certain proteins, known as swine cluster of differentiation (CD) antigens, found in pigs. During a workshop, researchers standardized the naming of 16 existing antibody groups and introduced 5 new swine CD antigens, which will help in better understanding the immune system of pigs. This is important because it lays the groundwork for better vaccine development and disease management in pigs, which could ultimately improve livestock health and production. Who this helps: Farmers and veterinarians working with pigs.

PubMed

Immunoprecipitation studies of monoclonal antibodies submitted to the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Aasted B, Gori K, Dominguez J, Ezquerra A, Bullido R +19 more

PubMed

Summary of the first round analyses of the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Saalmüller A, Pauly T, Aasted B, Jensen KT, Sachs DH +15 more

Plain English
This study looked at 176 monoclonal antibodies to understand how they interact with different types of pig blood cells. Researchers found 22 distinct groups of these antibodies that react in similar ways, which helps in identifying specific cell types. This is important because it lays the groundwork for detailed future studies that can lead to better understanding and treatment of diseases in pigs. Who this helps: This benefits researchers and veterinarians working with pigs and animal health.

PubMed

Summary of workshop findings for antibodies reacting with porcine T-cells and activation antigens: results from the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Pescovitz MD, Book BK, Aasted B, Dominguez J, Ezquerra A +15 more

Plain English
Researchers evaluated 195 antibodies related to pig immune cells and discovered that 57 of them were particularly relevant to T-cell markers. They organized 23 of these antibodies into specific groups based on their functions, identifying new interactions and characteristics, such as new markers for a type of T-cell (CD3) and changes in other markers depending on the cell's activation state. This research is important because it enhances our understanding of pig immunity, which can improve animal health and inform vaccine development. Who this helps: This helps veterinarians and researchers working with pig health and immunology.

PubMed

Analyses of monoclonal antibodies reacting with porcine CD3: results from the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Pescovitz MD, Book BK, Aasted B, Dominguez J, Ezquerra A +14 more

Plain English
The study looked at 57 monoclonal antibodies (mAb) that target specific proteins on pig T-cells to better understand how they function. Researchers identified six mAb that give similar results in tests and target important protein structures on the T-cells, known as CD3. They found that these antibodies can stimulate T-cells in various ways, which can help improve immune responses in pigs, a significant finding for veterinary medicine. Who this helps: This helps veterinarians and researchers working with pigs, particularly in improving their immune health.

PubMed

Analyses of monoclonal antibodies reacting with porcine CD5: results from the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Pescovitz MD, Book BK, Aasted B, Dominguez J, Bullido R +12 more

Plain English
This study looked at monoclonal antibodies, which are lab-made proteins that can target specific parts of cells in pigs. Researchers found that out of the 57 tested antibodies, two new ones were able to identify proteins similar to a standard antibody. This finding increases the number of known antibodies that react to the same pig cell marker to eight, which may help in understanding pig immune responses better. Who this helps: This helps researchers and veterinarians working with pigs.

PubMed

Analyses of monoclonal antibodies reacting with porcine wCD6: results from the Second International Swine CD Workshop.

1998

Veterinary immunology and immunopathology

Pescovitz MD, Book BK, Aasted B, Dominguez J, Bullido R +12 more

Plain English
Researchers studied 57 monoclonal antibodies that interact with a specific protein called wCD6 in pigs. They found that a new antibody, MIL8, works alongside an existing one (a38b2) and both can bind to a key protein from activated T-cells, showing similar reactions on different types of cells. This is important for improving our understanding of pig immune responses, which can help in veterinary medicine and animal health. Who this helps: This benefits veterinarians and researchers working with pigs.

PubMed

Report on the analyses of mAb reactive with porcine CD8 for the second international swine CD workshop.

1998

Veterinary immunology and immunopathology

Zuckermann FA, Pescovitz MD, Aasted B, Dominguez J, Trebichavsky I +12 more

Plain English
This research studied specific antibodies (mAbs) that react with a type of immune cell called CD8+ lymphocytes in pigs. Out of 57 antibodies tested, five new ones were found to uniquely recognize these cells, with one, called PG164A, identifying a new feature of CD8+ lymphocytes that wasn't known before. These findings are significant because they can help scientists better understand how these immune cells work in both healthy and sick pigs. Who this helps: This helps researchers and veterinarians working with swine health.

PubMed

Selective increase in CD4-positive graft-infiltrating mononuclear cells among the infiltrates in class I disparate kidney grafts undergoing rejection.

1997

Transplantation

Giangrande I, Yamada K, Arn S, Lorf T, Sachs DH +1 more

Plain English
This study examined how immune cells behave in kidney transplants that were either accepted or rejected by the body. Researchers found that in kidney transplants that were rejected, there were more CD4-positive immune cells—specifically, the number of these cells increased in the rejected kidneys compared to those that were accepted. This matters because it suggests that these CD4-positive cells play a critical role in causing the rejection of kidney transplants, which could help improve transplant strategies in the future. Who this helps: This helps patients receiving kidney transplants.

PubMed

Expression of an allogeneic MHC DRB transgene, through retroviral transduction of bone marrow, induces specific reduction of alloreactivity.

1997

Transplantation

Emery DW, Sablinski T, Shimada H, Germana S, Gianello P +9 more

Plain English
This study looked at whether adding a specific gene from donor cells (MHC class II DRB) to a patient’s own bone marrow cells can help the body accept transplanted kidneys without rejecting them. In an experiment with five mini pigs, one pig that received the gene showed successful kidney function without rejection for 2.5 years, while a control pig with a different gene rejected its transplant in just 120 days. This research matters because it offers a potential new method for preventing organ rejection, which is a major challenge after transplants. Who this helps: This helps patients needing organ transplants.

PubMed

Effect of ciprofloxacin on the pharmacokinetics of multiple-dose phenytoin serum concentrations.

1994

Therapeutic drug monitoring

Job ML, Arn SK, Strom JG, Jacobs NF, D'Souza MJ

Plain English
In this study, researchers wanted to see if taking ciprofloxacin, an antibiotic, affects the blood levels of phenytoin, a medication used for epilepsy. They found that, for most participants, taking ciprofloxacin didn't change phenytoin levels. However, one participant did experience notable drops in the medication's levels, which can lead to uncontrolled seizures. This is important because it means that doctors need to monitor patients closely when these two drugs are prescribed together to avoid possible complications. Who this helps: This helps patients taking both ciprofloxacin and phenytoin, especially those with epilepsy.

PubMed

Summary of first round cluster analysis: complete antibody panel.

1994

Veterinary immunology and immunopathology

Carr MM, Lunney JK, Arn S, Aasted B, Binns RM +5 more

Plain English
This study looked at how 141 different monoclonal antibodies interact with 60 types of cells. Researchers grouped these antibodies into 23 clusters based on their similarities. This analysis is important because it helps scientists understand which antibodies work best for targeting specific cell types, potentially improving treatments for various diseases. Who this helps: This aids researchers and doctors in developing better therapies for their patients.

PubMed

Publication data sourced from PubMed . Plain-English summaries generated by AI. Not medical advice.