About

Sarah Ho is the CVM Director of Student Engagement at the College of Veterinary Medicine at NC State University. Her role involves fostering student success and engagement within the college community. The page highlights her contact information and her position as a key figure in student development and involvement, but does not provide specific details about her research focus, academic background, or key contributions in the field of veterinary medicine.

Research topics

• Biology
• Genetics
• Cell biology
• Medicine
• Sociology
• Immunology
• Internal medicine
• Molecular biology
• Cancer research
• Bioinformatics
• Endocrinology
• Virology
• Pathology
• Microbiology

Selected publications

• Application of a framework to mitigate the risk of surgical site infection after exploratory celiotomy in horses: A retrospective study

  Veterinary Surgery · 2026-03-03

  articleOpen access

  OBJECTIVE: To describe the methodology used to identify the contributors to a perceived sudden increase in exploratory celiotomy surgical site infections (SSI) and complications at the North Carolina State University Veterinary Teaching Hospital (NCSU VTH) between 2019 and 2020 and evaluate the effect of the designed intervention up to 4 years after its implementation. STUDY DESIGN: Case-control retrospective study over a five-year period. ANIMALS: A total of 448 horses that underwent exploratory celiotomy for the treatment of acute abdominal pain were included. METHODS: Medical records of horses that underwent exploratory celiotomy between 2019-2024 were reviewed from software systems used at the NCSU VTH. A surgical audit was conducted to assess adherence to best practices and identify factors contributing to increased SSI incidence. This led to the development of an evidence-based intervention to address procedural deficiencies and incorporate preventative perioperative strategies. The approach, resultant protocols, and reduction of SSI incidence are described. Data were analyzed using Fisher's exact test and univariate logistic regression. Statistical significance was set to p < .05. RESULTS: A significant increase in %SSI was observed from 7.7% in 2019 to 29% in 2020 (p = .0067). Following new protocol implementation, %SSI decreased to 2.3%. CONCLUSION: A surgical audit enabled the development of an evidence-based intervention that significantly reduced SSI incidence after exploratory celiotomy surgery. CLINICAL SIGNIFICANCE: Surgical audits serve as critical quality-of-care measure, allowing hospitals to identify procedural deficiencies. There is currently no literature that describes structured processes to manage this kind of problem in veterinary medicine. Surgical audit implementation may help other hospitals faced with similar challenges.

  PublisherDOI

• Novel Application of Flow Cytometry Side Population Identifies Intestinal Stem Cells in Wild-type Pigs

  Physiology · 2025-05-01

  articleSenior author

  Severe intestinal ischemia is a critical emergency diagnosis in both human and veterinary medicine, with mortality rates up to 80%. Its underlying pathophysiology is multifactorial but fundamentally linked to the preservation or loss of the intestine’s epithelial lining – a crucial barrier separating the gut contents from the sterile body. This barrier is maintained by proliferative intestinal stem cells (ISCs) that continuously replace the epithelial lining, renewing it entirely approximately every six days. Given ISCs’ essential role in maintaining intestinal barrier integrity, their function following injury merits deeper investigation. However, animal studies of ISCs have been limited to murine models, which have demonstrated poor translatability to human application. Thus, there is a pressing need for improved animal models to advance our understanding of the reparative processes driven by ISCs. Pigs closely approximate human gastrointestinal anatomy and physiology, offering a promising alternative as a large animal model. However, studies of porcine ISCs (pISCs) have been limited by an absence of known external markers for identification. Current methods rely on internal cellular markers, necessitating fixation and precluding in vitro analyses, or the use of an expensive and singularly available transgenic pig model. Altogether, these limitations have hindered progress in leveraging pISCs as a translational study tool. The objective of this study was to implement an alternative method for identifying pISCs using a flow cytometry (FCM)-based approach known as "side population" (SP) analysis. SP uses a cell-permeable dye that is actively effluxed by the membrane-bound transporters in cycling cells such as ISCs and has been effectively used in identifying both mouse and human ISCs. In contrast, non-cycling cells ( e.g., epithelial cells) retain the dye, creating a distinct FCM fluorescent signature. Thus, we hypothesized that SP analysis could be used to identify live pISCs in a wild-type pig model. To this end, we first optimized both chemical and mechanical dissociation protocols to produce a single-cell suspension that, upon FCM analysis, contained a significantly greater SP fluorescent signature compared to traditional dissociation techniques. We then validated the SP specificity by using a Ca 2+ channel blocker control (Verapamil) to inhibit transporter-mediated dye efflux, effectively preventing the SP. These findings are consistent with SP analysis identifying cycling cells, including ISCs. Ongoing analyses aim to exclude CD45+ leukocytes and CD166+ Paneth and goblet cells to further purify this SP. Additionally, 3D cell culture will be used to confirm ISC identity and their proliferative capacity. Furthermore, concurrent evaluations of novel surface markers such as CD24 and CD44 are pending, which may provide additional alternatives for histological pISC identification. Future directions will include fluorescence-activated cell sorting (FACS) for confirmatory downstream qPCR analysis of ISC markers such as LGR5, HopX, and Olfm4. These data represent the first implementation of SP analysis for identifying ISCs in a porcine model. Establishing a method for live pISC isolation is foundational for broader investigations into their regenerative potential. Thus, this work has the potential to broaden our understanding of ISCs, ultimately leveraging their reparative capabilities to advance therapeutic strategies in human and veterinary medicine alike. NIH T35OD011070 Interdisciplinary Biomedical Research Training Program; The Discovery Fund This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

  PublisherDOI

• Reduction of apoptosis and preservation of stem-cell proliferation in intestinal transplantation allografts with normothermic machine perfusion

  Intestinal failure. · 2025-01-01

  articleOpen accessSenior author

  Background: Intestinal transplantation (IT) is the only lifesaving therapy for intestinal failure but is plagued by high rejection rates. Static cold storage (CS), the standard of allograft preservation, is known to induce damage. Normothermic machine perfusion (NMP) improves transplantation outcomes in other organs and may benefit IT. Preliminarily, NMP reduces apoptotic cells (CC3+), increases proliferative cells (Ki67+), and increases transplant recipient survival. We hypothesized that NMP upregulates anti-apoptotic, intestinal stem-cell proliferation, and wound healing pathways.

  PublisherOA PDFDOI

• Allograft Inflammation is Reduced with Normothermic Machine Perfusion in Intestinal Transplantation

  Intestinal failure. · 2025-01-01

  articleOpen accessSenior author

  Background: The only curative therapy for intestinal failure is transplantation. Intestinal transplantation (IT) following allograft static cold storage (CS) results in frequent rejection. Outcomes of other organ transplantation have improved with normothermic machine perfusion (NMP), partially through immune modulation. However, NMP in IT is nascent. Preliminarily, NMP stabilizes CD3+ lymphocytes while decreasing natural killer cells. We hypothesized that NMP reduces intestinal inflammatory signaling pathways and maintains the microbiome.

  PublisherOA PDFDOI

• Normothermic Machine Perfusion Mitigates Allograft Inflammation in Intestinal Transplantation

  American Journal of Transplantation · 2025-08-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Risk factors for strangulating lipoma obstruction and lipomata in horses

  Equine Veterinary Journal · 2025-10-04

  articleOpen access

  BACKGROUND: Strangulating lipoma obstruction (SLO) is the most common cause of equine small intestinal strangulation and is fatal without surgery. Currently, epidemiological information is primarily limited to signalment-related risk factors and requires further investigation. OBJECTIVES: To identify horse-level risk factors for SLO and/or abdominal lipoma(s) (LP) formation in horses with acute colic that underwent surgery or post-mortem examination at participating equine clinics. STUDY DESIGN: Prospective, international, multicentre, epidemiological study. METHODS: An epidemiological study was conducted over 27 months (January 2022-April 2024) in 8 clinics (UK n = 4, USA n = 4) to identify variables associated with altered likelihood of SLO and/or LP. Horses presenting with acute colic signs that underwent surgery or post-mortem examination were eligible. Those (i) that had SLO as the primary cause of colic, or (ii) those that had mesenteric and/or omental lipoma(ta) (LP) were compared to horses without lipomata. Signalment, adiposity, endocrine status, and lipomata deposition data were analysed using univariable and multivariable logistic regression models. RESULTS: Data from 392 horses was obtained (108 SLO; 190 LP). Increasing age (odds ratio [OR] 1.23) for every year increase in age 95% CI (95% CI: 1.17-1.30, p < 0.001), male sex (OR 1.78, 95% CI: 1.08-2.95, p = 0.02) and clinical indicators of Equine Metabolic Syndrome (EMS) (OR 4.77, 95% CI: 2.93-7.77, p < 0.001) were significantly associated with increased likelihood of SLO. Increasing age, clinical indicators of EMS, indicators of previous/current laminitis (hoof growth ring score), jejunal mesenteric fat score and omental fat scores were significantly associated with increased likelihood of LP. MAIN LIMITATIONS: Population restricted to horses with acute colic signs admitted to collaborating clinics. CONCLUSIONS: Measures to prevent adiposity and EMS development appear important to reduce the likelihood of LP and SLO. Further investigation of differential adipose tissue deposition between male and female horses is warranted.

  PublisherOA PDFDOI

• Observations from the First Series of Human Intestine Graft Normothermic Machine Preservation

  American Journal of Transplantation · 2025-08-01

  article
  PublisherDOI

• Fine tuning between regeneration and anti-apoptosis as a key advantage of using normothermic machine perfusion in intestinal transplantation

  Physiology · 2025-05-01

  articleSenior author

  Maintaining intestinal barrier integrity is critical to ensuring intestinal transplant (IT) patients’ health. Our research has focused on optimizing allograft viability during the storage period by mimicking a normal physiological environment through normothermic machine perfusion (NMP). In initial studies comparing NMP to traditional cold storage methods, NMP storage reduced apoptotic cells (CC3 + ), increased proliferative cells (Ki67 + ), and significantly improved recipient animal survival. We therefore hypothesized that NMP improves graft preservation via mechanisms of enhanced epithelial proliferation and reduced apoptosis. Porcine intestine underwent NMP storage for 6h followed by transplantation into a recipient. Biopsies were obtained at donor procurement (T0), following 6h NMP (T6), after 1h of in vivo post-transplant reperfusion (T1RP), and at 48h post-transplant (T48). Mechanisms of epithelial cell apoptosis and regenerative potential were evaluated utilizing transcriptomic and proteomic analyses of crypt derived cells and were confirmed using whole tissue immunofluorescence (IF). Gene biomarker expression of proliferation Ki67 was significantly upregulated in jejunal and ileal crypts at T6 and T1RP with increased KI67 + cell counts confirmed by IF. In the ileum, VEGFA upregulation likely enhanced oxygen supply for tissue repair. The intestinal stem cell (ISC) marker ATOH1, critical for secretory lineage differentiation, was downregulated in both the jejunum and ileum, suggesting a shift toward epithelial proliferation over differentiation during early post-transplant phases. Active and reserve ISC markers LGR5 and HOPX, respectively , remained stable in the jejunum and were downregulated in the ileum. Together, this data suggests a role of transit amplifying cell activation in epithelial barrier maintenance. We also found evidence of reduced apoptotic signals at T6 and T1RP, including a significant decrease in ileum CASP3 gene expression and a reduced number of CC3 + cells confirmed by IF in jejunum and ileum. Proteomic analyses revealed increased levels of anti-apoptotic proteins such as HYOU1, Regucalcin, and Galectin that regulate stress responses and cell death pathways, promoting cell survival and tissue repair and further corroborating the minimal tissue injury and favorable graft environment of NMP-mediated transplant. This molecular profile of NMP in IT revealed maintenance of epithelial barrier integrity via intracellular mechanisms targeting proliferation and apoptotic pathways. An enhanced renewal characterized by increased proliferation and reduced apoptosis underscores NMP's potential to optimize graft preservation and improve long-term transplantation outcomes. US DOD PR181265, NIH K01OD010199 SERCA, NIH 5T32OD011130-15, R01Al182590-01 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

  PublisherDOI

• Preservation of Epithelial Barrier Integrity and Microbial Populations with Mechanical Perfusion in Intestinal Transplantation

  Physiology · 2025-05-01

  articleSenior author

  Transplantation, the only definitive therapy for intestinal failure, is plagued by severe complications associated with intestinal barrier breakdown including the translocation of bacteria. Currently, clinical intestinal transplantation (IT) employs static cold storage (CS), however, normothermic machine perfusion (NMP) has significantly improved the outcome of solid organ transplantation beyond the intestine. Our preliminary work demonstrates that NMP significantly reduces intestinal epithelial damage compared to CS. The objective of this study was to evaluate the impact of NMP on epithelial barrier function and gut microbiota. We hypothesize that NMP preserves intestinal barrier function and maintains microbial populations resulting in a healthier allograft. We optimized a method to quantify real-time lactulose:mannitol (L/M) fluctuations to assess paracellular intestinal permeability. A mixture of mannitol (50 mg/kg) and lactulose (500 mg/kg) was administered into the proximal jejunal lumen (n=3) during continuous ex vivo perfusion. Plasma perfusate samples were collected hourly spanning NMP-storage time (18 hours). Additionally, shotgun proteomics and whole genome shotgun (WGS) sequencing were employed to evaluate tight junction protein expression and intestinal microbiome populations in the jejunum and ileum following NMP, respectively. L/M ratios successfully measured intestinal permeability and absorptive function up to 12 hours of NMP storage, when evidence intestinal barrier compromise was suspected based upon blood lactate values and epithelial damage observed in histology. Myosin IXB, a protein involved in tight junction integrity, was significantly elevated following NMP, indicating improved barrier function. Furthermore, the microbiome of the jejunum and ileum during NMP storage and post-transplant remained stable, suggesting that NMP effectively preserves the donor intestine’s microbial diversity without significant overgrowth of pathogens. Overall, current methods of NMP storage preserve intestinal barrier function and microbial populations, improving overall health of the donor intestine. These findings highlight the potential of NMP to in improve transplant outcomes by enhancing graft viability and maintaining intestinal homeostasis thus offering distinct advantages over CS. Funding: U.S. Department of Defense PR181265; NIH K01OD010199 SERCA, NIH 5T32OD011130-15, 1R01Al182590-01 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

  PublisherDOI

• Normothermic Machine Perfusion Mitigates Allograft Inflammation in Intestinal Transplantation

  Physiology · 2025-05-01

  articleSenior author

  The only life-saving therapy for intestinal failure patients who no longer tolerate parenteral nutrition is transplantation. Intestinal transplantation (IT) following the traditionally employed allograft static cold storage (CS) method results in frequent rejection. Improved outcomes of other solid organ transplantation have been achieved using normothermic machine perfusion (NMP)-based storage, in part through allograft immune modulation. The exploration of NMP in IT is nascent. Preliminary assays demonstrate that NMP stabilizes CD3 + intraepithelial lymphocytes in the jejunum and ileum while decreasing lamina propria natural killer cell populations at the end of storage. The objective of this study was to further evaluate the impact of NMP on intestinal inflammation using targeted genomic and shotgun proteomic assessments. We hypothesized that NMP would reduce allograft inflammatory signaling and improve IT outcomes. Porcine small intestine was procured (T0), stored for 6H at either 4°C (CS_T6) or perfused at 34°C (NMP_T6), and transplanted. Samples were collected at T0, T6, 1-hour post-transplant and reperfusion (T1RP), and euthanasia (T48). Mucosal scrapings of the jejunum and ileum were collected for proteomic and transcriptomic evaluations. Proteins from NMP and CS-stored intestine were extracted, separated, and ionized prior to identification with mass spectrometry (n=4-5). RNA from NMP-stored intestine was extracted, hybridized to a custom codeset, and analyzed using nanoString nCounter (n=3). Significance was set at p&lt;0.05. Proteomic assessments comparing CS and NMP identified elevated calprotectin in CS-ileum, a clinical marker of intestinal inflammation and rejection, though our conclusions were limited by low survival in CS transplant recipients. Because of the low survival of CS recipients, transcriptomic analyses were used to profile allograft changes over the duration of NMP-storage. Proinflammatory TNFA, CD69, IFNG, IL21, IL17, IL12, TBET, and TGFB increased following reperfusion, however, all except TNFA decreased by T48, with many returning to T0 levels. Cytokines associated with reduced inflammatory injury following intestinal transplantation, such as IL6, IL5, and IL21, significantly increased in jejunum over time. Additionally, the transcription of anti-inflammatory IL13 and GATA3 and markers of successful intestinal transplantation such as CCR10, IL22, CTLA4, and FOXP3 were significantly upregulated in T1RP and T48 jejunum. NMP increased key anti-inflammatory and epithelial recovery transcripts while reducing protein markers of inflammation compared to CS. While many of the cytokines elevated during NMP have been historically associated with inflammation, current literature has demonstrated dual roles that are anti-inflammatory ( IL6, 2, 5 ). Furthermore, transient inflammation in transplantation is inevitable given the unavoidable manipulation and ischemia that occurs during bowel procurement. Overall, NMP supported resolution of procurement-associated inflammation and a favorable immune environment which may improve small intestinal transplantation outcomes. NIH 5T32OD011130-15; U.S. Department of Defense PR181265; NIH K01OD010199 SERCA, This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

  PublisherDOI

Recent grants

• Intestinal stem cell responses to ischemic injury in a large animal model

  NIH · $608k · 2015–2021

Frequent coauthors

• Anthony T. Blikslager

  North Carolina State University

  34 shared

• John M. Freund

  North Carolina State University

  22 shared

• Amy Stieler Stewart

  North Carolina State University

  20 shared

• Cecilia R. Schaaf

  North Carolina State University

  17 shared

• Katherine S. Garman

  Duke University

  11 shared

• Scott T. Magness

  North Carolina State University

  11 shared

• Amanda L. Ziegler

  North Carolina State University

  10 shared

• Brittany Veerasammy

  North Carolina State University

  9 shared

Awards & honors

• Comparative Medicine and Translational Research Training Pro…