Clinical Focus

  • Residency

Honors & Awards

  • Best Basic/Translational Abstract, Holman Research Day, Stanford University Department of Surgery (2023)
  • Dr. Hilary Sanfey Outstanding Resident Award, Association of Women Surgeons (AWS) Foundation (2022)
  • The Resident Research Award, Stanford Department of Surgery (2021)
  • Best Basic/Translational Abstract, Holman Research Day, Stanford University Department of Surgery (2020)
  • The Resident Research Award, Stanford Department of Surgery (2020)
  • NIH Loan Repayment Program (LRP) - Renewal, National Institutes of Health (2019-2020)
  • NIH NCI F32, National Institutes of Health (2019 - present)
  • Best Basic/Translational Oral Presentation, Holman Research Day, Stanford University Department of Surgery (2019)
  • Excellence in Research Award, Surgical Oncology, American College of Surgeons (ACS) Clinical Congress (2019)
  • The Resident Research Award, Stanford Department of Surgery (2019)
  • Best Basic/Translational Oral Presentation, Holman Research Day, Stanford University Department of Surgery (2018)
  • Excellence in Research Award, Surgical Oncology, American College of Surgeons (ACS) Clinical Congress (2018)
  • Advanced Residency Training at Stanford (ARTS) Program, Stanford University School of Medicine (2017 - present)
  • NIH Loan Repayment Program (LRP), National Institutes of Health (2017 - 2019)
  • Resident Research Award, American College of Surgeons (ACS) (2017 - 2019)
  • Fall Courses Travel Award, Association of Academic Surgery (AAS) (2017)
  • The Donald R. Cooper, M.D. Award for Excellence in Surgery, Drexel University College of Medicine (2015)
  • Women’s Health Scholar, Drexel University College of Medicine (2015)
  • Fulbright Research Scholarship, U.S. Department of State (2010)
  • FLAS Graduate Fellowship, U.S. Department of Education (2009)
  • Firestone Medal for Excellence in Undergraduate Research, Stanford University (2008)
  • Honors, Human Biology, Stanford University (2008)

Current Clinical Interests

  • Surgery
  • Surgical Oncology
  • Wound Healing

Lab Affiliations

Graduate and Fellowship Programs

All Publications

  • Multiplexed evaluation of mouse wound tissue using oligonucleotide barcoding with single-cell RNA sequencing. STAR protocols Januszyk, M., Griffin, M., Mascharak, S., Talbott, H. E., Chen, K., Henn, D., Spielman, A. F., Parker, J. B., Liang, N. E., Cotterell, A., Guardino, N., Foster, D. S., Wagh, D., Coller, J., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2022; 4 (1): 101946


    Despite its rapidly increased availability for the study of complex tissue, single-cell RNA sequencing remains prohibitively expensive for large studies. Here, we present a protocol using oligonucleotide barcoding for the tagging and pooling of multiple samples from healing wounds, which are among the most challenging tissue types for this application. We describe steps to generate skin wounds in mice, followed by tissue harvest and oligonucleotide barcoding. This protocol is also applicable to other species including rats, pigs, and humans. For complete details on the use and execution of this protocol, please refer to Stoeckius etal. (2018),1 Galiano etal. (2004),2 and Mascharak etal. (2022).3.

    View details for DOI 10.1016/j.xpro.2022.101946

    View details for PubMedID 36525348

  • Macrophage inflammatory and regenerative response periodicity is programmed by cell cycle and chromatin state. Molecular cell Daniel, B., Belk, J. A., Meier, S. L., Chen, A. Y., Sandor, K., Czimmerer, Z., Varga, Z., Bene, K., Buquicchio, F. A., Qi, Y., Kitano, H., Wheeler, J. R., Foster, D. S., Januszyk, M., Longaker, M. T., Chang, H. Y., Satpathy, A. T. 2022


    Cell cycle (CC) facilitates cell division via robust, cyclical gene expression. Protective immunity requires the expansion of pathogen-responsive cell types, but whether CC confers unique gene expression programs that direct the subsequent immunological response remains unclear. Here, we demonstrate that single macrophages (MFs) adopt different plasticity states in CC, which leads to heterogeneous cytokine-induced polarization, priming, and repolarization programs. Specifically, MF plasticity to interferon gamma (IFNG) is substantially reduced during S-G2/M, whereas interleukin 4 (IL-4) induces S-G2/M-biased gene expression, mediated by CC-biased enhancers. Additionally, IL-4 polarization shifts the CC-phase distribution of MFs toward the G2/M phase, providing a subpopulation-specific mechanism for IL-4-induced, dampened IFNG responsiveness. Finally, we demonstrate CC-dependent MF responses in murine and human disease settings invivo, including Th2-driven airway inflammation and pulmonary fibrosis, where MFs express an S-G2/M-biased tissue remodeling gene program. Therefore, MF inflammatory and regenerative responses are gated by CC in a cyclical, phase-dependent manner.

    View details for DOI 10.1016/j.molcel.2022.11.017

    View details for PubMedID 36521490

  • Machine Learning-Based Desmoplastic Signatures Predict Patient Outcomes in Pancreatic Ductal Adenocarcinoma Guo, J. L., Mascharak, S., Foster, D. S., Guardino, N. J., Griffin, M., Miller, E., Raghavan, S., Longacre, T. A., Norton, J. A., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S53-S54
  • Where There Is Fat There Is Fibrosis: Elucidating the Mechanisms of Creeping Fat-Driven Stricture Formation Bauer-Rowe, K. E., Kim, A., Griffin, M., Foster, D., Guardino, N., Guo, J. L., Talbott, H. E., Norton, J. A., Hyun, J. S., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S59-S60
  • Multiomic analysis reveals conservation of cancer-associated fibroblast phenotypes across species and tissue of origin. Cancer cell Foster, D. S., Januszyk, M., Delitto, D., Yost, K. E., Griffin, M., Guo, J., Guardino, N., Delitto, A. E., Chinta, M., Burcham, A. R., Nguyen, A. T., Bauer-Rowe, K. E., Titan, A. L., Salhotra, A., Jones, R. E., da Silva, O., Lindsay, H. G., Berry, C. E., Chen, K., Henn, D., Mascharak, S., Talbott, H. E., Kim, A., Nosrati, F., Sivaraj, D., Ransom, R. C., Matthews, M., Khan, A., Wagh, D., Coller, J., Gurtner, G. C., Wan, D. C., Wapnir, I. L., Chang, H. Y., Norton, J. A., Longaker, M. T. 2022


    Cancer-associated fibroblasts (CAFs) are integral to the solid tumor microenvironment. CAFs were once thought to be a relatively uniform population of matrix-producing cells, but single-cell RNA sequencing has revealed diverse CAF phenotypes. Here, we further probed CAF heterogeneity with a comprehensive multiomics approach. Using paired, same-cell chromatin accessibility and transcriptome analysis, we provided an integrated analysis of CAF subpopulations over a complex spatial transcriptomic and proteomic landscape to identify three superclusters: steady state-like (SSL), mechanoresponsive (MR), and immunomodulatory (IM) CAFs. These superclusters are recapitulated across multiple tissue types and species. Selective disruption of underlying mechanical force or immune checkpoint inhibition therapy results in shifts in CAF subpopulation distributions and affected tumor growth. As such, the balance among CAF superclusters may have considerable translational implications. Collectively, this research expands our understanding of CAF biology, identifying regulatory pathways in CAF differentiation and elucidating therapeutic targets in a species- and tumor-agnostic manner.

    View details for DOI 10.1016/j.ccell.2022.09.015

    View details for PubMedID 36270275

  • Partial Tendon Injury at the Tendon-to-Bone Enthesis Activates Skeletal Stem Cells. Stem cells translational medicine Titan, A. L., Davitt, M., Foster, D., Salhotra, A., Menon, S., Chen, K., Fahy, E., Lopez, M., Jones, R. E., Baiu, I., Burcham, A., Januszyk, M., Gurtner, G., Fox, P., Chan, C., Quarto, N., Longaker, M. 2022


    The tendon enthesis plays a critical role in facilitating movement and reducing stress within joints. Partial enthesis injuries heal in a mechanically inferior manner and never achieve healthy tissue function. The cells responsible for tendon-to-bone healing remain incompletely characterized and their origin is unknown. Here, we evaluated the putative role of mouse skeletal stem cells (mSSCs) in the enthesis after partial-injury. We found that mSSCs were present at elevated levels within the enthesis following injury and that these cells downregulated TGFβ signaling pathway elements at both the RNA and protein levels. Exogenous application of TGFβ post-injury led to a reduced mSSC response and impaired healing, whereas treatment with a TGFβ inhibitor (SB43154) resulted in a more robust mSSC response. Collectively, these data suggest that mSSCs may augment tendon-to-bone healing by dampening the effects of TGFβ signaling within the mSSC niche.

    View details for DOI 10.1093/stcltm/szac027

    View details for PubMedID 35640155

  • Multi-omic analysis reveals divergent molecular events in scarring and regenerative wound healing. Cell stem cell Mascharak, S., Talbott, H. E., Januszyk, M., Griffin, M., Chen, K., Davitt, M. F., Demeter, J., Henn, D., Bonham, C. A., Foster, D. S., Mooney, N., Cheng, R., Jackson, P. K., Wan, D. C., Gurtner, G. C., Longaker, M. T. 1800


    Regeneration is the holy grail of tissue repair, but skin injury typically yields fibrotic, non-functional scars. Developing pro-regenerative therapies requires rigorous understanding of the molecular progression from injury to fibrosis or regeneration. Here, we report the divergent molecular events driving skin wound cells toward scarring or regenerative fates. We profile scarring versus YAP-inhibition-induced wound regeneration at the transcriptional (single-cell RNA sequencing), protein (timsTOF proteomics), and tissue (extracellular matrix ultrastructural analysis) levels. Using cell-surface barcoding, we integrate these data to reveal fibrotic and regenerative "molecular trajectories" of healing. We show that disrupting YAP mechanotransduction yields regenerative repair by fibroblasts with activated Trps1 and Wnt signaling. Finally, via invivo gene knockdown and overexpression in wounds, we identify Trps1 as a key regulatory gene that is necessary and partially sufficient for wound regeneration. Our findings serve as a multi-omic map of wound regeneration and could have therapeutic implications for pathologic fibroses.

    View details for DOI 10.1016/j.stem.2021.12.011

    View details for PubMedID 35077667

  • Surgery for Hereditary Diffuse Gastric Cancer: Long-Term Outcomes. Cancers Forrester, J. D., Foster, D., Ford, J. M., Longacre, T. A., Ladabaum, U., Fry, S., Norton, J. A. 2022; 14 (3)


    Gastric cancer is inherited as an autosomal dominant condition in hereditary diffuse gastric cancer (HDGC). The gene associated with HDGC is an E-cadherin gene CDH1. At the time of initiation of this study, it was estimated that 70% of patients who inherited the CDH1 gene mutation would develop gastric cancer. We hypothesized that the rate of signet ring cell cancer in asymptomatic patients with CDH1 mutations may be higher than anticipated and that the surgery could be conducted with acceptable short-term and long-term complications suggesting that the quality of life with the surgery is acceptable.We prospectively studied the role of total gastrectomy in symptomatic and asymptomatic patients with CDH1 mutations. A total of 43 patients with mutations of the CDH1 gene were studied prospectively, including 8 with symptoms and 35 without symptoms. Total gastrectomy was recommended to each. Quality of life was assessed in patients who underwent prophylactic gastrectomy. Proportions are compared with Fisher's exact test.In total, 13 (30%) asymptomatic patients declined surgery. Total gastrectomy was performed in 8 symptomatic patients and 22 asymptomatic patients of whom only 3 asymptomatic patients (14%) had endoscopically proven signet ring cell cancer preoperatively, while 21 of 22 (95%) had it on final pathology (p = 0.05). Each asymptomatic patient was T1, N0, while seven out of eight symptomatic patients had T3-T4 tumors and six had positive lymph nodes. None had operative complications or operative death. The median follow-up was 7 years. Five (63%) symptomatic patients died, while only one (95%) prophylactic patient died of a non-gastric cancer- or surgery-related issue (p = 0.05). A total of 15 prophylactic patients had long-term follow-up. Each had significant weight loss (mean 23%) but all had a normal body mass index. In total, 40% had bile reflux gastritis controlled with sucralfate. Each returned to work and, if given the choice, said that they would undergo the surgery again.Total gastrectomy is indicated for patients who have an inherented CDH1 mutation. Endoscopic screening is not reliable for diagnosing signet ring cell stomach cancer. If patients wait for symptoms, they will have a more advanced disease and significantly reduced survival. Operative complications of prophylactic gastrectomy are minimal, and long-term quality of life is acceptable.

    View details for DOI 10.3390/cancers14030728

    View details for PubMedID 35158993

  • Where There Is Fat There Is Fibrosis: Elucidating the Mechanisms of Creeping Fat-Driven Stricture Formation Bauer-Rowe, K. E., Griffin, M., Foster, D., desJardins-Park, H. E., Mascharak, S., Norton, J. A., Hyun, J. S., Longaker, M. T. ELSEVIER SCIENCE INC. 2021: S65
  • Cancer-Associated Fibroblasts Share Highly Conserved Phenotypes and Functions Across Tumor Types and Species Foster, D. S., Januszyk, M., Yost, K. E., Chinta, M., Titan, A. L., Wapnir, I. L., Gurtner, G. C., Chang, H. Y., Norton, J. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2021: S243-S244
  • Integrated spatial multiomics reveals fibroblast fate during tissue repair. Proceedings of the National Academy of Sciences of the United States of America Foster, D. S., Januszyk, M., Yost, K. E., Chinta, M. S., Gulati, G. S., Nguyen, A. T., Burcham, A. R., Salhotra, A., Ransom, R. C., Henn, D., Chen, K., Mascharak, S., Tolentino, K., Titan, A. L., Jones, R. E., da Silva, O., Leavitt, W. T., Marshall, C. D., des Jardins-Park, H. E., Hu, M. S., Wan, D. C., Wernig, G., Wagh, D., Coller, J., Norton, J. A., Gurtner, G. C., Newman, A. M., Chang, H. Y., Longaker, M. T. 2021; 118 (41)


    In the skin, tissue injury results in fibrosis in the form of scars composed of dense extracellular matrix deposited by fibroblasts. The therapeutic goal of regenerative wound healing has remained elusive, in part because principles of fibroblast programming and adaptive response to injury remain incompletely understood. Here, we present a multimodal -omics platform for the comprehensive study of cell populations in complex tissue, which has allowed us to characterize the cells involved in wound healing across both time and space. We employ a stented wound model that recapitulates human tissue repair kinetics and multiple Rainbow transgenic lines to precisely track fibroblast fate during the physiologic response to skin injury. Through integrated analysis of single cell chromatin landscapes and gene expression states, coupled with spatial transcriptomic profiling, we are able to impute fibroblast epigenomes with temporospatial resolution. This has allowed us to reveal potential mechanisms controlling fibroblast fate during migration, proliferation, and differentiation following skin injury, and thereby reexamine the canonical phases of wound healing. These findings have broad implications for the study of tissue repair in complex organ systems.

    View details for DOI 10.1073/pnas.2110025118

    View details for PubMedID 34620713

  • JUN promotes hypertrophic skin scarring via CD36 in preclinical in vitro and in vivo models. Science translational medicine Griffin, M. F., Borrelli, M. R., Garcia, J. T., Januszyk, M., King, M., Lerbs, T., Cui, L., Moore, A. L., Shen, A. H., Mascharak, S., Diaz Deleon, N. M., Adem, S., Taylor, W. L., desJardins-Park, H. E., Gastou, M., Patel, R. A., Duoto, B. A., Sokol, J., Wei, Y., Foster, D., Chen, K., Wan, D. C., Gurtner, G. C., Lorenz, H. P., Chang, H. Y., Wernig, G., Longaker, M. T. 2021; 13 (609): eabb3312


    [Figure: see text].

    View details for DOI 10.1126/scitranslmed.abb3312

    View details for PubMedID 34516825

  • Skin angiography assisted mastectomy in secondary breast angiosarcoma: Complete clinical response after neoadjuvant immunotherapy. The breast journal Ju, T., Foster, D., Titan, A., Najjar, S., Bean, G. R., Ganjoo, K., Wapnir, I. 2021


    Radiation-induced breast angiosarcoma, or secondary angiosarcoma (SAS), is a rare entity with a high risk of metastatic recurrence. Herein, we describe the use of intraoperative fluorescence-based skin angiography to guide surgical resection following a novel immunotherapy-based regimen for SAS resulting in a complete pathological response.

    View details for DOI 10.1111/tbj.14270

    View details for PubMedID 34173294

  • Preventing Engrailed-1 activation in fibroblasts yields wound regeneration without scarring. Science (New York, N.Y.) Mascharak, S., desJardins-Park, H. E., Davitt, M. F., Griffin, M., Borrelli, M. R., Moore, A. L., Chen, K., Duoto, B., Chinta, M., Foster, D. S., Shen, A. H., Januszyk, M., Kwon, S. H., Wernig, G., Wan, D. C., Lorenz, H. P., Gurtner, G. C., Longaker, M. T. 2021; 372 (6540)


    Skin scarring, the end result of adult wound healing, is detrimental to tissue form and function. Engrailed-1 lineage-positive fibroblasts (EPFs) are known to function in scarring, but Engrailed-1 lineage-negative fibroblasts (ENFs) remain poorly characterized. Using cell transplantation and transgenic mouse models, we identified a dermal ENF subpopulation that gives rise to postnatally derived EPFs by activating Engrailed-1 expression during adult wound healing. By studying ENF responses to substrate mechanics, we found that mechanical tension drives Engrailed-1 activation via canonical mechanotransduction signaling. Finally, we showed that blocking mechanotransduction signaling with either verteporfin, an inhibitor of Yes-associated protein (YAP), or fibroblast-specific transgenic YAP knockout prevents Engrailed-1 activation and promotes wound regeneration by ENFs, with recovery of skin appendages, ultrastructure, and mechanical strength. This finding suggests that there are two possible outcomes to postnatal wound healing: a fibrotic response (EPF-mediated) and a regenerative response (ENF-mediated).

    View details for DOI 10.1126/science.aba2374

    View details for PubMedID 33888614

  • Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries LANCET Knight, S. R., Shaw, C. A., Pius, R., Drake, T. M., Norman, L., Ademuyiwa, A. O., Adisa, A. O., Aguilera-Arevalo, M., Al-Saqqa, S. W., Al-Slaibi, I. S., Bhangu, A., Biccard, B. M., Brocklehurst, P., Costas-Chavarri, A., Chu, K. M., Dare, A. J., Elhadi, M., Fairfield, C. J., Fitzgerald, J., Ghosh, D. N., Glasbey, J., Henegouwen, M., Ingabire, J., Kingham, T., Lapitan, M. M., Lawani, I., Lieske, B., Lilford, R. J., Martin, J., Mclean, K. A., Moore, R. L., Morton, D., Nepogodiev, D., Ntirenganya, F., Pata, F., Pinkney, T. D., Qureshi, A. U., Ramos-De la Medina, A., Riad, A. M., Salem, H., Simoes, J., Spence, R. T., Smart, N. J., Tabiri, S., Thomas, H. S., Weiser, T. G., West, M. A., Whitaker, J., Harrison, E. M., GlobalSurg Collaborative, Global Surg Writing Grp 2021; 397 (10272): 387–97


    80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality.This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with, NCT03471494.Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70-8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39-8·80) and upper-middle-income countries (2·06, 1·11-3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26-11·59) and upper-middle-income countries (3·89, 2·08-7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications.Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications.National Institute for Health Research Global Health Research Unit.

    View details for DOI 10.1016/S0140-6736(21)00001-5

    View details for Web of Science ID 000614227700026

    View details for PubMedID 33485461

    View details for PubMedCentralID PMC7846817

  • Wounds Inhibit Tumor Growth In Vivo ANNALS OF SURGERY Hu, M. S., Maan, Z. N., Leavitt, T., Hong, W., Rennert, R. C., Marshall, C. D., Borrelli, M. R., Zhu, T. N., Esquivel, M., Zimmermann, A., McArdle, A., Chung, M. T., Foster, D. S., Jones, R., Gurtner, G. C., Giaccia, A. J., Lorenz, H., Weissman, I. L., Longaker, M. T. 2021; 273 (1): 173–80
  • Xenogeneic skin transplantation promotes angiogenesis and tissue regeneration through activated Trem2+ macrophages. Science advances Henn, D., Chen, K., Fehlmann, T., Trotsyuk, A. A., Sivaraj, D., Maan, Z. N., Bonham, C. A., Barrera, J. A., Mays, C. J., Greco, A. H., Moortgat Illouz, S. E., Lin, J. Q., Steele, S. R., Foster, D. S., Padmanabhan, J., Momeni, A., Nguyen, D., Wan, D. C., Kneser, U., Januszyk, M., Keller, A., Longaker, M. T., Gurtner, G. C. 2021; 7 (49): eabi4528


    [Figure: see text].

    View details for DOI 10.1126/sciadv.abi4528

    View details for PubMedID 34851663

  • Epidermal-Derived Hedgehog Signaling Drives Mesenchymal Proliferation during Digit Tip Regeneration. Journal of clinical medicine Maan, Z. N., Rinkevich, Y., Barrera, J., Chen, K., Henn, D., Foster, D., Bonham, C. A., Padmanabhan, J., Sivaraj, D., Duscher, D., Hu, M., Yan, K., Januszyk, M., Longaker, M. T., Weissman, I. L., Gurtner, G. C. 2021; 10 (18)


    Hand injuries often result in significant functional impairments and are rarely completely restored. The spontaneous regeneration of injured appendages, which occurs in salamanders and newts, for example, has been reported in human fingertips after distal amputation, but this type of regeneration is rare in mammals and is incompletely understood. Here, we study fingertip regeneration by amputating murine digit tips, either distally to initiate regeneration, or proximally, causing fibrosis. Using an unbiased microarray analysis, we found that digit tip regeneration is significantly associated with hair follicle differentiation, Wnt, and sonic hedgehog (SHH) signaling pathways. Viral over-expression and genetic knockouts showed the functional significance of these pathways during regeneration. Using transgenic reporter mice, we demonstrated that, while both canonical Wnt and HH signaling were limited to epidermal tissues, downstream hedgehog signaling (through Gli) occurred in mesenchymal tissues. These findings reveal a mechanism for epidermal/mesenchyme interactions, governed by canonical hedgehog signaling, during digit regeneration. Further research into these pathways could lead to improved therapeutic outcomes after hand injuries in humans.

    View details for DOI 10.3390/jcm10184261

    View details for PubMedID 34575372

  • Proceed with Caution: Mouse Deep Digit Flexor Tendon Injury Model. Plastic and reconstructive surgery. Global open Titan, A. L., Fahy, E. n., Chen, K. n., Foster, D. S., Bennett-Kennett, R. n., Dauskardt, R. H., Gurtner, G. C., Chang, J. n., Fox, P. M., Longaker, M. T. 2021; 9 (1): e3359


    The purpose of this study was to determine the feasibility of using mouse models for translational study of flexor tendon repair and reconstruction.Quantitative data detailing the gross anatomy, biomechanical characteristics, and microscopic structure of the deep digit flexor tendon (DDF) of the mouse hindpaw were obtained. Histological characterization of the DDF and the anatomy of the digit in the mouse hindpaw are detailed. Biomechanical testing determined the load-to-failure, stress, elastic modulus, and the site of tendon failure.In gross anatomy, the origins and insertions of the mouse deep digit flexor tendon are similar to those of the human digit, surrounded by a synovial sheath that is only 1- to 2-cells thick. A neurovascular network runs on each side of the digit outside the synovial sheath, but does not clearly penetrate it. The thickness of the DDF is 0.14 ± 0.03 mm and the width is 0.3 ± 0.03 mm. The thickness of the DDF is less than that of 9-0 nylon needle. The mean failure force of the deep flexor tendon was 2.79 ± 0.53N.The gross anatomy of the mouse hindpaw digit is similar to that of the human digit except for key differences seen in the synovial sheath and vascular supply. The dimensions of the mouse DDF make it challenging to create a clinically translatable repair model using currently available surgical techniques. Despite the similarities between the human and mouse anatomy, and the powerful basic science tools available in murine models, mice are an unreliable model for assessing flexor tendon injury and repair.

    View details for DOI 10.1097/GOX.0000000000003359

    View details for PubMedID 33552814

    View details for PubMedCentralID PMC7859083

  • Prrx1 Fibroblasts Represent a Pro-fibrotic Lineage in the Mouse Ventral Dermis. Cell reports Leavitt, T., Hu, M. S., Borrelli, M. R., Januszyk, M., Garcia, J. T., Ransom, R. C., Mascharak, S., desJardins-Park, H. E., Litzenburger, U. M., Walmsley, G. G., Marshall, C. D., Moore, A. L., Duoto, B., Adem, S., Foster, D. S., Salhotra, A., Shen, A. H., Griffin, M., Shen, E. Z., Barnes, L. A., Zielins, E. R., Maan, Z. N., Wei, Y., Chan, C. K., Wan, D. C., Lorenz, H. P., Chang, H. Y., Gurtner, G. C., Longaker, M. T. 2020; 33 (6): 108356


    Fibroblast heterogeneity has been shown within the unwounded mouse dorsal dermis, with fibroblast subpopulations being identified according to anatomical location and embryonic lineage. Using lineage tracing, we demonstrate that paired related homeobox 1 (Prrx1)-expressing fibroblasts are responsible for acute and chronic fibroses in the ventral dermis. Single-cell transcriptomics further corroborated the inherent fibrotic characteristics of Prrx1 fibroblasts during wound repair. In summary, we identify and characterize a fibroblast subpopulation in the mouse ventral dermis with intrinsic scar-forming potential.

    View details for DOI 10.1016/j.celrep.2020.108356

    View details for PubMedID 33176144

  • Ectoderm-Derived Wnt and Hedgehog Signaling Drive Digit Tip Regeneration Barrera, J., Maan, Z. N., Foster, D., Henn, D., Chen, K., Bonham, C., Januszyk, M., Longaker, M. T., Weissman, I., Gurtner, G. C. ELSEVIER SCIENCE INC. 2020: S186
  • Detection, Scoring, and Classification of Solid Organ Fibroses with Machine Learning Analysis Mascharak, S., desJardins-Park, H. E., Davitt, M., Foster, D. S., Chinta, M., Wan, D. C., Wernig, G., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: S222
  • A Surgical Model for Investigating the Role of Creeping Fat in Intestinal Fibrosis Bauer-Rowe, K. E., Foster, D., Titan, A., Chinta, M., desJardins-Park, H., Griffin, M., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: S50–S51
  • Wounds Heal by Tissue-Resident Fibroblast Progenitors that Proliferate Polyclonally and Mechanoresponsively Foster, D. S., Chinta, M., Salhotra, A., Nguyen, A. T., Burcham, A., Mascharak, S., Januszyk, M., Gurtner, G. C., Wernig, G., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: S236–S237
  • Peripheral Motor Neuron Activity Influences over Local Sarcoma Progression Davitt, M., Foster, D., Mascharak, S., desJardins-Park, H., Norton, J., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: S230–S231
  • Characterization of Diabetic and Non-Diabetic Foot Ulcers Using Single-Cell RNA-Sequencing. Micromachines Januszyk, M., Chen, K., Henn, D., Foster, D. S., Borrelli, M. R., Bonham, C. A., Sivaraj, D., Wagh, D., Longaker, M. T., Wan, D. C., Gurtner, G. C. 2020; 11 (9)


    Background: Recent advances in high-throughput single-cell sequencing technologies have led to their increasingly widespread adoption for clinical applications. However, challenges associated with tissue viability, cell yield, and delayed time-to-capture have created unique obstacles for data processing. Chronic wounds, in particular, represent some of the most difficult target specimens, due to the significant amount of fibrinous debris, extracellular matrix components, and non-viable cells inherent in tissue routinely obtained from debridement. Methods: Here, we examined the feasibility of single cell RNA sequencing (scRNA-seq) analysis to evaluate human chronic wound samples acquired in the clinic, subjected to prolonged cold ischemia time, and processed without FACS sorting. Wound tissue from human diabetic and non-diabetic plantar foot ulcers were evaluated using an optimized 10X Genomics scRNA-seq platform and analyzed using a modified data pipeline designed for low-yield specimens. Cell subtypes were identified informatically and their distributions and transcriptional programs were compared between diabetic and non-diabetic tissue. Results: 139,000 diabetic and non-diabetic wound cells were delivered for 10X capture after either 90 or 180 min of cold ischemia time. cDNA library concentrations were 858.7 and 364.7 pg/L, respectively, prior to sequencing. Among all barcoded fragments, we found that 83.5% successfully aligned to the human transcriptome and 68% met the minimum cell viability threshold. The average mitochondrial mRNA fraction was 8.5% for diabetic cells and 6.6% for non-diabetic cells, correlating with differences in cold ischemia time. A total of 384 individual cells were of sufficient quality for subsequent analyses; from this cell pool, we identified transcriptionally-distinct cell clusters whose gene expression profiles corresponded to fibroblasts, keratinocytes, neutrophils, monocytes, and endothelial cells. Fibroblast subpopulations with differing fibrotic potentials were identified, and their distributions were found to be altered in diabetic vs. non-diabetic cells. Conclusions: scRNA-seq of clinical wound samples can be achieved using minor modifications to standard processing protocols and data analysis methods. This simple approach can capture widespread transcriptional differences between diabetic and non-diabetic tissue obtained from matched wound locations.

    View details for DOI 10.3390/mi11090815

    View details for PubMedID 32872278

  • Doxycycline Reduces Scar Thickness and Improves Collagen Architecture ANNALS OF SURGERY Moore, A. L., desJardins-Park, H. E., Duoto, B. A., Mascharak, S., Murphy, M. P., Irizarry, D. M., Foster, D. S., Jones, R. E., Barnes, L. A., Marshall, C. D., Ransom, R. C., Wernig, G., Longaker, M. T. 2020; 272 (1): 183–93
  • Fibroblast Heterogeneity in and Its Implications for Plastic and Reconstructive Surgery: A Basic Science Review PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN desJardins-Park, H. E., Chinta, M. S., Foster, D. S., Borrelli, M. R., Shen, A. H., Wan, D. C., Longaker, M. T. 2020; 8 (6)
  • Fibroblast Heterogeneity in and Its Implications for Plastic and Reconstructive Surgery: A Basic Science Review. Plastic and reconstructive surgery. Global open desJardins-Park, H. E., Chinta, M. S., Foster, D. S., Borrelli, M. R., Shen, A. H., Wan, D. C., Longaker, M. T. 2020; 8 (6): e2927


    Fibroblasts' integral role in tissue development, maintenance, and disease represents a fast-growing field of basic science research. Although fibroblasts were long thought to be a homogeneous cell population, recent research has illuminated the unforeseen complexity of these cells, giving rise to the rapidly expanding research field of "fibroblast heterogeneity." Fibroblasts play a critical role in states of tissue fibrosis such as skin scarring, which affects hundreds of millions of patients annually and causes severe aesthetic, developmental, and functional morbidity. Beyond scarring, major organ fibrosis is an enormous public health concern responsible for nearly half of all deaths in the United States. Because fibrosis is a conserved response to tissue damage in all organs, the study of fibroblasts throughout the body may help us to understand their role in the conditions most relevant to plastic and reconstructive surgery-for instance, skin scarring (eg, from burns, traumatic lacerations, or surgical incisions), "pathological" scarring (hypertrophic scars, keloids), and capsular contracture. Here, we present a basic science review of fibroblast heterogeneity in wound healing, cancer, organ fibrosis, and human dermal architecture. The field of fibroblast heterogeneity is young, and many of the insights discussed have yet to be translated clinically. However, plastic surgeons stand in a unique position to bridge these discoveries into clinical realities. We hope this information can spur readers to consider both what questions in plastic surgery can be studied from the lens of fibroblast heterogeneity, and how these preclinical insights can be translated to improving care of our patients.

    View details for DOI 10.1097/GOX.0000000000002927

    View details for PubMedID 32766071

    View details for PubMedCentralID PMC7339369

  • Pancreatic Cancer Associated Fibroblasts (CAF): Under-Explored Target for Pancreatic Cancer Treatment. Cancers Norton, J. n., Foster, D. n., Chinta, M. n., Titan, A. n., Longaker, M. n. 2020; 12 (5)


    Pancreatic cancer is the 4th leading cause of cancer deaths in the United States. The pancreatic cancer phenotype is primarily a consequence of oncogenes disturbing the resident pancreas parenchymal cell repair program. Many solid tumor types including pancreatic cancer have severe tumor fibrosis called desmoplasia. Desmoplastic stroma is coopted by the tumor as a support structure and CAFs aid in tumor growth, invasion, and metastases. This stroma is caused by cancer associated fibroblasts (CAFs), which lay down extensive connective tissue in and around the tumor cells. CAFs represent a heterogeneous population of cells that produce various paracrine molecules such as transforming growth factor-beta (TGF-beta) and platelet derived growth factors (PDGFs) that aid tumor growth, local invasion, and development of metastases. The hard, fibrotic shell of desmoplasia serves as a barrier to the infiltration of both chemo- and immunotherapy drugs and host immune cells to the tumor. Although there have been recent improvements in chemotherapy and surgical techniques for management of pancreatic cancer, the majority of patients will die from this disease. Therefore, new treatment strategies are clearly needed. CAFs represent an under-explored potential therapeutic target. This paper discusses what we know about the role of CAFs in pancreatic cancer cell growth, invasion, and metastases. Additionally, we present different strategies that are being and could be explored as anti-CAF treatments for pancreatic cancer.

    View details for DOI 10.3390/cancers12051347

    View details for PubMedID 32466266

  • Elucidating the fundamental fibrotic processes driving abdominal adhesion formation. Nature communications Foster, D. S., Marshall, C. D., Gulati, G. S., Chinta, M. S., Nguyen, A. n., Salhotra, A. n., Jones, R. E., Burcham, A. n., Lerbs, T. n., Cui, L. n., King, M. E., Titan, A. L., Ransom, R. C., Manjunath, A. n., Hu, M. S., Blackshear, C. P., Mascharak, S. n., Moore, A. L., Norton, J. A., Kin, C. J., Shelton, A. A., Januszyk, M. n., Gurtner, G. C., Wernig, G. n., Longaker, M. T. 2020; 11 (1): 4061


    Adhesions are fibrotic scars that form between abdominal organs following surgery or infection, and may cause bowel obstruction, chronic pain, or infertility. Our understanding of adhesion biology is limited, which explains the paucity of anti-adhesion treatments. Here we present a systematic analysis of mouse and human adhesion tissues. First, we show that adhesions derive primarily from the visceral peritoneum, consistent with our clinical experience that adhesions form primarily following laparotomy rather than laparoscopy. Second, adhesions are formed by poly-clonal proliferating tissue-resident fibroblasts. Third, using single cell RNA-sequencing, we identify heterogeneity among adhesion fibroblasts, which is more pronounced at early timepoints. Fourth, JUN promotes adhesion formation and results in upregulation of PDGFRA expression. With JUN suppression, adhesion formation is diminished. Our findings support JUN as a therapeutic target to prevent adhesions. An anti-JUN therapy that could be applied intra-operatively to prevent adhesion formation could dramatically improve the lives of surgical patients.

    View details for DOI 10.1038/s41467-020-17883-1

    View details for PubMedID 32792541

  • Evaluation of Outcomes Following Surgery for Locally Advanced Pancreatic Neuroendocrine Tumors. JAMA network open Titan, A. L., Norton, J. A., Fisher, A. T., Foster, D. S., Harris, E. J., Worhunsky, D. J., Worth, P. J., Dua, M. M., Visser, B. C., Poultsides, G. A., Longaker, M. T., Jensen, R. T. 2020; 3 (11): e2024318


    Although outcome of surgical resection of liver metastases from pancreatic neuroendocrine tumors (PNETs) has been extensively studied, little is known about surgery for locally advanced PNETs; it was listed recently by the European neuroendocrine tumor society as a major unmet need.To evaluate the outcome of patients who underwent surgery for locally aggressive PNETs.This retrospective single-center case series reviewed consecutive patients who underwent resection of T3/T4 PNETs at a single academic institution. Data collection occurred from 2003 to 2018. Data analysis was performed in August 2019.Disease-free survival (primary outcome) and overall mortality (secondary outcome) were assessed with Kaplan-Meier analysis. Recurrence risk (secondary outcome, defined as identification of tumor recurrence on imaging) was assessed with Cox proportional hazard models adjusting for covariates.In this case series, 99 patients with locally advanced nondistant metastatic PNET (56 men [57%]) with a mean (SEM) age of 57.0 (1.4) years and a mean (SEM) follow-up of 5.3 (0.1) years underwent surgically aggressive resections. Of those, 4 patients (4%) underwent preoperative neoadjuvant treatment (including peptide receptor radionuclide therapy and chemotherapy); 18 patients (18%) underwent pancreaticoduodenectomy, 68 patients (69%) had distal or subtotal pancreatic resection, 10 patients (10%) had total resection, and 3 patients (3%) had other pancreatic procedures. Additional organ resection was required in 86 patients (87%): spleen (71 patients [71%]), major blood vessel (17 patients [17%]), bowel (2 patients [2%]), stomach (4 patients [4%]), and kidney (2 patients [2%]). Five-year disease-free survival was 61% (61 patients) and 5-year overall survival was 91% (91 patients). Of those living, 75 patients (76%) had an Eastern Cooperative Oncology Group score of less than or equal to 1 at last followup. Lymph node involvement (HR, 7.66; 95% CI, 2.78-21.12; P < .001), additional organ resected (HR, 6.15; 95% CI, 1.61-23.55; P = .008), and male sex (HR, 3.77; 95% CI, 1.68-8.97; P = .003) were associated with increased risk of recurrence. Functional tumors had a lower risk of recurrence (HR, 0.23; CI, 0.06-0.89; P = .03). Required resection of blood vessels was not associated with a significant increase recurrence risk.In this case series, positive lymph node involvement and resection of organs with tumor involvement were associated with an increased recurrence risk. These subgroups may require adjuvant systemic treatment. These findings suggest that patients with locally advanced PNETs who undergo surgical resection have excellent disease-free and overall survival.

    View details for DOI 10.1001/jamanetworkopen.2020.24318

    View details for PubMedID 33146734

  • Breast Surgery Anesthesiologist's Manual of Surgical Procedures Wapnir, I. L., Foster, D. S., Momeni, A., Schmiesing, C. Dr. Richard A. Jaffe. 2020; 6
  • Management of Pancreatic Islet Cell Tumors Excluding Gastrinoma Current Surgical Therapy Foster, D. S., Norton, J. A. John Cameron. 2020; 13
  • Endogenous Breast Cancer Shows Clonal Proliferation of Cancer Associated Fibroblasts at Primary Tumor and Metastatic Sites Foster, D. S., Chinta, M., Nguyen, A. T., Salhotra, A., Ransom, R., Jones, R., Titan, A. L., Mascharak, S., Norton, J. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S262
  • Role of the Skeletal Stem Cell in Achilles Tendon to Bone Interface Healing Titan, A. L., Jones, R., Salhotra, A., Robertson, K. S., Foster, D., Menon, S., Murphy, M., Lucero, G. V., Chan, C. K., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S228–S229
  • Effect of Mechanical Loading on Clonality of Injured Flexor Tendons after Repair Titan, A. L., Foster, D., Jones, R., Salhotra, A., Nguyen, A. T., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S221
  • Fibroblast Proliferation in Wound Healing Is Clonal and Focal Adhesion Kinase-Dependent Chinta, M., Foster, D., Nguyen, A. T., Salhotra, A., Ransom, R. C., Jones, R., Titan, A. L., Marshall, C., Mascharak, S., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S223
  • Regenerative Skin Healing Through Targeted Modulation of Engrailed1-Negative Fibroblasts Mascharak, S., desJardins-Park, H. E., Moore, A. L., Borrelli, M. R., Chinta, M., Foster, D., Lorenz, H., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S228
  • Cancer-Associated Fibroblasts Persist but Show Decreased Fibroblast Activation Protein Expression after Neoadjuvant Chemotherapy in Human Pancreatic Ductal Adenocarcinoma Foster, D. S., Nguyen, A. T., Chinta, M., Titan, A. L., Salhotra, A., Jones, R., Mascharak, S., Norton, J., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S257–S258
  • Tumors Co-Opt Fibroblast Wound Healing Capacity Foster, D. S., Mascharak, S., Nguyen, A. T., Chinta, M., Salhotra, A., Titan, A. L., Jones, R., da Silva, O., Norton, J. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: S231–S232
  • Wounds Inhibit Tumor Growth In Vivo. Annals of surgery Hu, M. S., Maan, Z. N., Leavitt, T., Hong, W. X., Rennert, R. C., Marshall, C. D., Borrelli, M. R., Zhu, T. N., Esquivel, M., Zimmermann, A., McArdle, A., Chung, M. T., Foster, D. S., Jones, R. E., Gurtner, G. C., Giaccia, A. J., Lorenz, H. P., Weissman, I. L., Longaker, M. T. 2019


    OBJECTIVE: The aim of this study was to determine the interaction of full thickness excisional wounds and tumors in vivo.SUMMARY OF BACKGROUND DATA: Tumors have been described as wounds that do not heal due to similarities in stromal composition. On the basis of observations of slowed tumor growth after ulceration, we hypothesized that full thickness excisional wounds would inhibit tumor progression in vivo.METHODS: To determine the interaction of tumors and wounds, we developed a tumor xenograft/allograft (human head and neck squamous cell carcinoma SAS/mouse breast carcinoma 4T1) wound mouse model. We examined tumor growth with varying temporospatial placement of tumors and wounds or ischemic flap. In addition, we developed a tumor/wound parabiosis model to understand the ability of tumors and wounds to recruit circulating progenitor cells.RESULTS: Tumor growth inhibition by full thickness excisional wounds was dose-dependent, maintained by sequential wounding, and relative to distance. This effect was recapitulated by placement of an ischemic flap directly adjacent to a xenograft tumor. Using a parabiosis model, we demonstrated that a healing wound was able to recruit significantly more circulating progenitor cells than a growing tumor. Tumor inhibition by wound was unaffected by presence of an immune response in an immunocompetent model using a mammary carcinoma. Utilizing functional proteomics, we identified 100 proteins differentially expressed in tumors and wounds.CONCLUSION: Full thickness excisional wounds have the ability to inhibit tumor growth in vivo. Further research may provide an exact mechanism for this remarkable finding and new advances in wound healing and tumor biology.

    View details for PubMedID 30829705

  • Wound healing and fibrosis: current stem cell therapies. Transfusion Jones, R. E., Foster, D. S., Hu, M. S., Longaker, M. T. 2019; 59 (S1): 884-892


    Scarring is a result of the wound healing response and causes tissue dysfunction after injury. This process is readily evident in the skin, but also occurs internally across organ systems in the form of fibrosis. Stem cells are crucial to the innate tissue healing response and, as such, present a possible modality to therapeutically promote regenerative healing while minimizing scaring. In this review, the cellular basis of scaring and fibrosis is examined. Current stem cell therapies under exploration for skin wound healing and internal organ fibrosis are discussed. While most therapeutic approaches rely on the direct application of progenitor-type cells to injured tissue to promote healing, novel strategies to manipulate the scarring response are also presented. As our understanding of developmental and stem cell biology continues to increase, therapies to encourage regeneration of healthy functional tissue after damage secondary to injury or disease will continue to expand.

    View details for DOI 10.1111/trf.14836

    View details for PubMedID 30737822

  • Management of Ileal Neuroendocrine Tumors with Liver Metastases. Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract Fisher, A. T., Titan, A. L., Foster, D. S., Worth, P. J., Poultsides, G. A., Visser, B. C., Dua, M. M., Norton, J. A. 2019


    Assessment of treating metastatic ileal neuroendocrine tumors (NETs) with complete resection of primary tumor, nodal and liver metastases, plus administration of long-acting somatostatin analogues (SSAs).A prospective database was queried for patients with ileal or pancreatic NETs with pathology-confirmed liver metastases and tumor somatostatin receptors. Patients did not have MEN-1 and had no previous treatment. The impacts of SSA treatment on the primary outcome of survival and secondary outcome of progression-free survival were assessed with Kaplan-Meier analysis. Log rank test was used to compare overall and progression-free survival among groups.Seventeen ileal NET patients and 36 pancreatic NET patients who underwent surgical resection between 2001 and 2018, who had pathology-confirmed liver metastases and confirmed tumor somatostatin receptors, did not have MEN-1, and had no previous treatment were identified. Median follow-up for patients with ileal NETs was 80 months (range 0-197 months) and 32 months (range 1-182 months) for pancreatic NETs. Five-year survival was 93% and 72% for ileal and pancreatic NET, respectively. Progression-free 5-year survival was 70% and 36% for ileal and pancreatic NET, respectively. Overall 5-year survival for pNETs was greater in those patients treated with SSA (79%) compared to those who underwent surgery alone (34%, p < 0.01). The average ECOG score was low for surviving patients with ileal (0.15) and pancreatic NET (0.73) indicating a good quality of life.Resection of primary lymph node and liver metastatic ileal or pancreatic NETs followed with continued SSAs is associated with an excellent progression-free and overall survival and minimal side effects.

    View details for DOI 10.1007/s11605-019-04309-7

    View details for PubMedID 31346887

  • Skeletal Stem Cell-Schwann Cell Circuitry in Mandibular Repair. Cell reports Jones, R. E., Salhotra, A. n., Robertson, K. S., Ransom, R. C., Foster, D. S., Shah, H. N., Quarto, N. n., Wan, D. C., Longaker, M. T. 2019; 28 (11): 2757–66.e5


    Regenerative paradigms exhibit nerve dependency, including regeneration of the mouse digit tip and salamander limb. Denervation impairs regeneration and produces morphological aberrancy in these contexts, but the direct effect of innervation on the stem and progenitor cells enacting these processes is unknown. We devised a model to examine nerve dependency of the mouse skeletal stem cell (mSSC), the progenitor responsible for skeletal development and repair. We show that after inferior alveolar denervation, mandibular bone repair is compromised because of functional defects in mSSCs. We present mSSC reliance on paracrine factors secreted by Schwann cells as the underlying mechanism, with partial rescue of the denervated phenotype by Schwann cell transplantation and by Schwann-derived growth factors. This work sheds light on the nerve dependency of mSSCs and has implications for clinical treatment of mandibular defects.

    View details for DOI 10.1016/j.celrep.2019.08.021

    View details for PubMedID 31509739

  • Flexor Tendon: Development, Healing, Adhesion Formation, and Contributing Growth Factors. Plastic and reconstructive surgery Titan, A. L., Foster, D. S., Chang, J. n., Longaker, M. T. 2019; 144 (4): 639e–647e


    Management of flexor tendon injuries of the hand remains a major clinical problem. Even with intricate repair, adhesion formation remains a common complication. Significant progress has been made to better understand the mechanisms of healing and adhesion formation. However, there has been slow progress in the clinical prevention and reversal of flexor tendon adhesions. The goal of this article is to discuss recent literature relating to tendon development, tendon healing, and adhesion formation to identify areas in need of further research. Additional research is needed to understand and compare the molecular, cellular, and genetic mechanisms involved in flexor tendon morphogenesis, postoperative healing, and mechanical loading. Such knowledge is critical to determine how to improve repair outcomes and identify new therapeutic strategies to promote tissue regeneration and prevent adhesion formation.

    View details for DOI 10.1097/PRS.0000000000006048

    View details for PubMedID 31568303

  • A Clearing Technique to Enhance Endogenous Fluorophores in Skin and Soft Tissue. Scientific reports Foster, D. S., Nguyen, A. T., Chinta, M. n., Salhotra, A. n., Jones, R. E., Mascharak, S. n., Titan, A. L., Ransom, R. C., da Silva, O. L., Foley, E. n., Briger, E. n., Longaker, M. T. 2019; 9 (1): 15791


    Fluorescent proteins are used extensively in transgenic animal models to label and study specific cell and tissue types. Expression of these proteins can be imaged and analyzed using fluorescent and confocal microscopy. Conventional confocal microscopes cannot penetrate through tissue more than 4-6 μm thick. Tissue clearing procedures overcome this challenge by rendering thick specimens into translucent tissue. However, most tissue clearing techniques do not satisfactorily preserve expression of endogenous fluorophores. Using simple adjustments to the BABB (Benzoic Acid Benzyl Benzoate) clearing methodology, preservation of fluorophore expression can be maintained. Modified BABB tissue clearing is a reliable technique to clear skin and soft tissue specimens for the study of dermal biology, wound healing and fibrotic pathologies.

    View details for DOI 10.1038/s41598-019-50359-x

    View details for PubMedID 31673001

  • Doxycycline Reduces Scar Thickness and Improves Collagen Architecture. Annals of surgery Moore, A. L., desJardins-Park, H. E., Duoto, B. A., Mascharak, S., Murphy, M. P., Irizarry, D. M., Foster, D. S., Jones, R. E., Barnes, L. A., Marshall, C. D., Ransom, R. C., Wernig, G., Longaker, M. T. 2018


    OBJECTIVE: To investigate the effects of local doxycycline administration on skin scarring.BACKGROUND: Skin scarring represents a major source of morbidity for surgical patients. Doxycycline, a tetracycline antibiotic with off-target effects on the extracellular matrix, has demonstrated antifibrotic effects in multiple organs. However, doxycycline's potential effects on skin scarring have not been explored in vivo.METHODS: Female C57BL/6J mice underwent dorsal wounding following an established splinted excisional skin wounding model. Doxycycline was administered by local injection into the wound base following injury. Wounds were harvested upon complete wound closure (postoperative day 15) for histological examination and biomechanical testing of scar tissue.RESULTS: A one-time dose of 3.90 mM doxycycline (2 mg/mL) within 12 hours of injury was found to significantly reduce scar thickness by 24.8% (P < 0.0001) without compromising tensile strength. The same effect could not be achieved by oral dosing. In doxycycline-treated scar matrices, collagen I content was significantly reduced (P = 0.0317) and fibers were favorably arranged with significantly increased fiber randomness (P = 0.0115). Common culprits of altered wound healing mechanics, including angiogenesis and inflammation, were not impacted by doxycycline treatment. However, engrailed1 profibrotic fibroblasts, responsible for scar extracellular matrix deposition, were significantly reduced with doxycycline treatment (P = 0.0005).CONCLUSIONS: Due to the substantial improvement in skin scarring and well-established clinical safety profile, locally administered doxycycline represents a promising vulnerary agent. As such, we favor rapid translation to human patients as an antiscarring therapy.

    View details for PubMedID 30585822

  • Author Correction: Genetic dissection of clonal lineage relationships with hydroxytamoxifen liposomes. Nature communications Ransom, R. C., Foster, D. S., Salhotra, A., Jones, R. E., Marshall, C. D., Leavitt, T., Murphy, M. P., Moore, A. L., Blackshear, C. P., Brett, E. A., Wan, D. C., Longaker, M. T. 2018; 9 (1): 4411


    In the original version of this Article, the authors inadvertently omitted Elizabeth A. Brett, who contributed to the generation of the histology figures, from the author list.This has now been corrected in both the PDF and HTML versions of the Article.

    View details for PubMedID 30341306

  • Management of Chronic Wounds-2018. JAMA Jones, R. E., Foster, D. S., Longaker, M. T. 2018; 320 (14): 1481-1482

    View details for DOI 10.1001/jama.2018.12426

    View details for PubMedID 30326512

  • Acta2, Tnc, and Col24a1 Expression Are Associated with Abdominal Adhesion Formation Marshall, C. D., Foster, D. S., Ransom, R. C., Manjunath, A., Gulati, G., Hu, M. S., Moore, A. L., Barnes, L. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2018: E128
  • Nerve-Dependent Mandibular Regeneration by Skeletal Stem Cells in Fracture Repair Jones, R., Ransom, R. C., Salhotra, A., Foster, D. S., Wan, D. C., Longaker, M. T. ELSEVIER SCIENCE INC. 2018: S197
  • Reduced Scar Thickness Achieved by Topical Doxycycline Is Mediated by Specific Skin Fibroblast Populations and Not Immune Cell Infiltrate Moore, A. L., Murphy, M. P., Irizarry, D. M., Des Jardins-Park, H. E., Duoto, B. A., Mascharak, S., Foster, D. S., Jones, R., Wernig, G., Longaker, M. T. ELSEVIER SCIENCE INC. 2018: S210–S211
  • Clonal Analysis of Local Fibroblasts in Wound Healing and Tumor Stroma Foster, D. S., Ransom, R. C., Nguyen, A. T., Salhotra, A., Jones, R. E., Hu, M. S., Norton, J. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2018: S236
  • The evolving relationship of wound healing and tumor stroma. JCI insight Foster, D. S., Jones, R. E., Ransom, R. C., Longaker, M. T., Norton, J. A. 2018; 3 (18)


    The stroma in solid tumors contains a variety of cellular phenotypes and signaling pathways associated with wound healing, leading to the concept that a tumor behaves as a wound that does not heal. Similarities between tumors and healing wounds include fibroblast recruitment and activation, extracellular matrix (ECM) component deposition, infiltration of immune cells, neovascularization, and cellular lineage plasticity. However, unlike a wound that heals, the edges of a tumor are constantly expanding. Cell migration occurs both inward and outward as the tumor proliferates and invades adjacent tissues, often disregarding organ boundaries. The focus of our review is cancer associated fibroblast (CAF) cellular heterogeneity and plasticity and the acellular matrix components that accompany these cells. We explore how similarities and differences between healing wounds and tumor stroma continue to evolve as research progresses, shedding light on possible therapeutic targets that can result in innovative stromal-based treatments for cancer.

    View details for DOI 10.1172/jci.insight.99911

    View details for PubMedID 30232274

  • Gastrinomas: Medical or Surgical Treatment. Endocrinology and metabolism clinics of North America Norton, J. A., Foster, D. S., Ito, T., Jensen, R. T. 2018; 47 (3): 577–601


    This article reviews the role of surgical and medical management in patients with Zollinger-Ellison syndrome (ZES) due to a gastrin-secreting neuroendocrine tumor (gastrinoma). It concentrates on the status at present but also briefly reviews the changes over time in treatment approaches. Generally, surgical and medical therapy are complementary today; however, in some cases, such as patients with ZES and multiple endocrine neoplasia type 1, the treatment approach remains controversial.

    View details for PubMedID 30098717

  • Management of Liver Neuroendocrine Tumors in 2018. JAMA oncology Foster, D. S., Jensen, R., Norton, J. A. 2018

    View details for PubMedID 30178021

  • Fibroblasts and wound healing: an update. Regenerative medicine des Jardins-Park, H. E., Foster, D. S., Longaker, M. T. 2018

    View details for PubMedID 30062921

  • Genetic dissection of clonal lineage relationships with hydroxytamoxifen liposomes. Nature communications Ransom, R. C., Foster, D. S., Salhotra, A., Jones, R. E., Marshall, C. D., Leavitt, T., Murphy, M. P., Moore, A. L., Blackshear, C. P., Wan, D. C., Longaker, M. T. 2018; 9 (1): 2971


    Targeted genetic dissection of tissues to identify precise cell populations has vast biological and therapeutic applications. Here we develop an approach, through thepackaging and delivery of 4-hydroxytamoxifen liposomes (LiTMX), that enables localized induction of CreERT2 recombinase in mice. Our method permits precise, in vivo, tissue-specific clonal analysis with both spatial and temporal control. This technology is effective using mice with both specific and ubiquitous Cre drivers in a variety of tissue types, under conditions of homeostasis and post-injury repair, and is highly efficient for lineage tracing and genetic analysis. This methodology is directly and immediately applicable to the developmental biology, stem cell biology and regenerative medicine, and cancer biology fields.

    View details for PubMedID 30061668

  • Incidence and Prognosis of Primary Gastrinomas in the Hepatobiliary Tract JAMA SURGERY Norton, J. A., Foster, D. S., Blumgart, L. H., Poultsides, G. A., Visser, B. C., Fraker, D. L., Alexander, H., Jensen, R. T. 2018; 153 (3): e175083

    View details for PubMedID 29365025

  • Axillary reverse mapping with indocyanine green or isosulfan blue demonstrate similar crossover rates to radiotracer identified sentinel nodes JOURNAL OF SURGICAL ONCOLOGY Foster, D., Choy, N., Porter, C., Ahmed, S., Wapnir, I. 2018; 117 (3): 336–40


    Sentinel lymph node (SLN) resection is imperative for breast cancer staging. Axillary reverse mapping (ARM) can preserve arm draining nodes and lymphatics during surgery. ARM is generally performed with isosulfan blue (ISB), restricting its use for concurrent SLN biopsy. Indocyanine green (ICG) could serve as an alternative to ISB for ARM procedures.SLN mapping and biopsy was performed via periareolar injection of 99 technetium-sulfur colloid (99m TcSc, TSC). ISB and ICG were injected in the upper arm. Blue-stained lymphatics or nodes were visualized in the axilla; ICG was identified using the SPY Elite® system.Twenty-three patients underwent SLN biopsy with or without axillary node dissection and ARM procedures. Twenty of these patients had at least one hot node; 12 patients had SLNs that were only hot, 6 hot/blue/fluorescent, and 2 hot/fluorescent. Overall, crossover of ARM agents with SLNs occurred in 8 cases. Inspection of the axillary cavity after SLN biopsy revealed fluorescent lymphatics and nodes remaining in 14 and 7 patients, respectively. Blue lymphatics and blue nodes were detected in fewer cases.Nearly one-third of patients showed crossover between breast and arm draining nodes, which provides insight as to why some patients develop lymphedema symptoms after SLN biopsy. ICG and ISB identify similar numbers of SLNs. As such ICG could substitute for ISB in ARM procedures.

    View details for PubMedID 29228459

  • Endoscopic Excision of Benign Facial Masses in Children: A Review of Outcomes. Journal of laparoendoscopic & advanced surgical techniques. Part A Foster, D. n., Sinclair, T. J., Taylor, J. S., Dutta, S. n., Lorenz, H. P., Bruzoni, M. n. 2018


    Benign masses of the eyebrow and forehead are common in pediatric patients and can result in facial asymmetry, discomfort, or super-infection. Excision is classically conducted via an incision directly over the mass, which can produce sub-optimal cosmesis. Recently, an endoscopic approach using pediatric brow-lift equipment has been adopted. We reviewed our center's experience with endoscopic removal of benign facial lesions and compared these cases with an equivalent series of open cases.A retrospective chart review was conducted to identify pediatric cases of endoscopic and open removal of benign eyebrow or forehead lesions at our institution from 2009 to 2016. Clinical and cosmetic outcomes were reviewed.A total of 40 endoscopic and 25 open cases of excision of benign facial lesions in children were identified. For the patients who underwent endoscopic excision, the majority (85%) presented with a cyst located at the eyebrow. Histologic examination revealed 36 dermoid cysts (90%), 2 epidermal cysts, and 2 pilomatrixomas. Of the 36 cases with post-operative follow-up, 32 patients (89%) had an uncomplicated recovery with good cosmesis. Two patients had an eyebrow droop that resolved without intervention. One patient had localized numbness overlying the site, but no motor deficits. One patient presented with a recurrent dermoid cyst that required open resection. For the patients who underwent open excision, the majority (52%) had dermoid cysts located at the eyebrow. Of the 22 cases with follow-up, 20 of the patients had an uncomplicated recovery (90%). Comparing the rate of complications, there was no statistically significant difference between the two groups (P = 1.0).Endoscopic excision of benign forehead and eyebrow lesions in pediatric patients is feasible and yields excellent cosmetic results. When compared with open excision, complication rates are similar between both approaches and a facial scar can be avoided with an endoscopic approach.

    View details for PubMedID 29446701

  • Wound Healing and Fibrosis: Current Stem Cell Therapies Transfusion Jones, R., Foster, D. S., Hu, M., Longaker, M. T. 2018

    View details for DOI 10.1111/trf.14836

  • Surgical Site Infections after Inguinal Hernia Repairs Performed in Low and Middle Human Development Index Countries: A Systematic Review. Surgical infections Cai, L. Z., Foster, D. n., Kethman, W. C., Weiser, T. G., Forrester, J. D. 2017


    Inguinal hernias are a common disorder in low- and middle-human development index countries (LMHDICs). Poor access to surgical care and lack of patient awareness often lead to delayed presentations of incarcerated or strangulated hernias and their associated morbidities. There is a scarcity of data on the baseline incidence of surgical site infections (SSIs) after hernia repair procedures in LMHDICs.We performed a systematic review of the literature describing the incidence and management of SSIs after inguinal hernia repair in LMHDICs. We conducted qualitative and quantitative analyses of manuscripts describing patients undergoing hernia repair to establish a baseline SSI rate for this procedure in these settings.Three hundred twenty-three abstracts were identified after applying search criteria, and 31 were suitable for the quantitative analysis. The overall pooled SSI rate was 4.1 infections/100 open hernia repairs (95% confidence interval [CI] 3.0-5.3 infections/100 open repairs), which is consistent with infection rates from high-human development index countries. A separate subgroup analysis of laparoscopic hernia repairs found a weighted pooled SSI rate of 0.4 infections/100 laparoscopic repairs (95% CI 0-2.4 infections/100 laparoscopic repairs).As surgical access continues to expand in LMHDIC settings, it is imperative to monitor surgical outcomes and ensure that care is provided safely. Establishing a baseline SSI rate for inguinal hernia repairs offers a useful benchmark for future studies and surgical programs in these countries.

    View details for PubMedID 29048997

  • Surgical Site Infections after Appendectomy Performed in Low and Middle Human Development-Index Countries: A Systematic Review. Surgical infections Foster, D. n., Kethman, W. n., Cai, L. Z., Weiser, T. G., Forrester, J. D. 2017


    Acute appendicitis is a common surgical emergency worldwide. Early intervention is associated with better outcomes. In low and middle Human Development-Index Countries (LMHDICs), late presentation and poor access to healthcare facilities can contribute to greater illness severity and higher complication rates, such as post-operative surgical site infections (SSIs). The current rate of SSIs post-appendectomy in low- and middle-index settings has yet to be described.We performed a systemic review of the literature describing the incidence and management of SSIs after appendectomy in LMHDICs. We conducted qualitative and quantitative analysis of the data in manuscripts describing patients undergoing appendectomy to establish a baseline SSI rate for this procedure in these settings.Four hundred twenty-three abstracts were initially identified. Of these, 35 studies met the criteria for qualitative and quantitative analysis. The overall weighted, pooled SSI rated were 17.9 infections/100 open appendectomies (95% confidence interval [CI] 10.4-25.3 infections/100 open appendectomies) and 8.8 infections/100 laparoscopic appendectomies (95% CI 4.5-13.2 infections/100 laparoscopic appendectomies). The SSI rates were higher in complicated appendicitis and when pre-operative antibiotic use was not specified.Observed SSI rates after appendectomy in LMHDICs are dramatically higher than rates in high Human Development-Index Countries. This is particularly true in cases of open appendectomy, which remains the most common surgical approach in LMHDICs. These findings highlight the need for SSI prevention in LMHDICs, including prompt access to medical and surgical care, routine pre-operative antibiotic use, and implementation of bundled care packages and checklists.

    View details for PubMedID 29058569

  • Regression of experimental NIS-expressing breast cancer brain metastases in response to radioiodide/gemcitabine dual therapy ONCOTARGET Renier, C., Do, J., Reyna-Neyra, A., Foster, D., De, A., Vogel, H., Jeffrey, S. S., Tse, V., Carrasco, N., Wapnir, I. 2016; 7 (34): 54811-54824


    Treating breast cancer brain metastases (BCBMs) is challenging. Na+/I- symporter (NIS) expression in BCBMs would permit their selective targeting with radioiodide (131I-). We show impressive enhancement of tumor response by combining131I- with gemcitabine (GEM), a cytotoxic radiosensitizer. Nude mice mammary fat-pad (MFP) tumors and BCBMs were generated with braintropic MDA-MB-231Br cells transduced with bicistronically-linked NIS and firefly luciferase cDNAs. Response was monitored in vivo via bioluminescent imaging and NIS tumor expression.131I-/GEM therapy inhibited MFP tumor growth more effectively than either agent alone. BCBMs were treated with: high or low-dose GEM (58 or 14.5 mg/Kg×4); 131I- (1mCi or 2×0.5 mCi 7 days apart); and 131I-/GEM therapy. By post-injection day (PID) 25, 82-86% of controls and 78-83% of 131I--treated BCBM grew, whereas 17% low-dose and 36% high-dose GEM regressed. The latter tumors were smaller than the controls with comparable NIS expression (~20% of cells). High and low-dose 131I-/ GEM combinations caused 89% and 57% tumor regression, respectively. High-dose GEM/131I- delayed tumor growth: tumors increased 5-fold in size by PID45 (controls by PID18). Although fewer than 25% of cells expressed NIS, GEM/131I- caused dramatic tumor regression in NIS-transduced BCBMs. This effect was synergistic, and supports the hypothesis that GEM radiosensitizes cells to 131I-.

    View details for DOI 10.18632/oncotarget.10238

    View details for Web of Science ID 000385435000059

  • Palliative Surgery for Advanced Cancer: Identifying Evidence-Based Criteria for Patient Selection: Case Report and Review of Literature JOURNAL OF PALLIATIVE MEDICINE Foster, D., Shaikh, M. F., Gleeson, E., Babcock, B. D., Ringold, D., Bowne, W. B. 2016; 19 (1): 22-29


    Criteria for selecting patients with advanced cancer for palliative surgery (PS) remains poorly defined. Decision making for PS requires realistic treatment goals with well-defined criteria. Here we discuss a 71-year-old Jehovah's Witness with advanced stage renal cell carcinoma (RCC) who presented with profound anemia due to intractable bleeding from gastric metastasis. After repeated attempts with endoscopic and angiographic management, she underwent surgical palliation. Through this case, we developed 10-item evidence-based criteria for selecting patients for PS.The study objective was to provide a review of pertinent literature for PS and identify evidence-based criteria for patient selection. These criteria were relevant for selecting this patient with metastatic RCC and may prove beneficial for selecting advanced cancer patients for PS.A MEDLINE search revealed 175 publications relevant to PS. Among these, 17 articles defining patient selection criteria (PSC) were reviewed. A frequency-based analysis of each criterion was performed. Another search returned 30 cases of RCC gastric metastases from 25 published reports. Outcome analysis was determined by the Kaplan-Meier actuarial method.Ten criteria were identified: symptom control, prognosis, preoperative performance status, quality of life (QoL), tumor burden amenable to palliation, procedure-related morbidity and mortality, feasibility of nonsurgical therapies, anticipated hospitalization, requirement for additional palliation, and cost. This patient met all inclusion criteria and underwent a successful gastrectomy. Median survival for patients with RCC gastric metastasis was 20 months.This report illustrates an example of implementation of evidence-based criteria for selecting advanced cancer patients for PS. Validation of these criteria is warranted.

    View details for DOI 10.1089/jpm.2015.0146

    View details for Web of Science ID 000367057700007

    View details for PubMedID 26565437

  • Pancreatic mucinous cystic neoplasm in a transgender patient WORLD JOURNAL OF SURGICAL ONCOLOGY Foster, D., Shaikh, M. F., Gleeson, E., Babcock, B. D., Lin, J., Ownbey, R. T., Hysell, M. E., Ringold, D., Bowne, W. B. 2015; 13


    Cystic pancreatic lesions are increasingly more frequent detected clinical entities. Mucinous cystic neoplasm (MCN) is a hormone-related pancreatic tumor (HRTP) with a strong predominance in young and middle-aged females.Here, we present the case of a 31-year-old surgically transgendered female-to-male patient with a history of alcoholic pancreatitis, on chronic testosterone therapy. He was found to have a pancreatic MCN and underwent distal pancreatectomy and splenectomy.To our knowledge, this is the first reported case of a transgender patient with a history of hormone replacement therapy (HRT) and pancreatic MCN. We consider possible mechanisms for the pathogenesis to explain this patient's neoplasm.

    View details for DOI 10.1186/s12957-015-0620-8

    View details for Web of Science ID 000357085900001

    View details for PubMedID 26104783

    View details for PubMedCentralID PMC4486435

  • Richter-type Spigelian hernia: A case report and review of the literature. International journal of surgery case reports Foster, D., Nagarajan, S., Panait, L. 2015; 6C: 160-162


    Abdominal wall hernias through the arcuate line termed Spigelian hernias are uncommon. These hernias presenting as a Richter-type, with strangulation of part of the circumference of the bowel wall is very rare.We report a 27-year-old male patient who presented with a Richter-type Spigelian hernia.A MEDLINE literature search of this rare entity yielded six publications presenting Richter-type Spigelian hernias. All of these articles and accompanying references were thoroughly reviewed. There was no gender or anatomical side predominance among the patients. All except our patient presented here were elderly. Pain was the most common symptom and was present in all patients. All patients underwent surgical repair and none reported recurrence of their hernia afterwards.Richter-type Spigelian hernia is rare and has been reported infrequently in the existing literature. Clinical diagnosis is challenging and CT scan is the diagnostic study of choice. Surgical repair is the definitive treatment and involves primary or mesh repair of the defect as appropriate. Necrotic bowel should be resected and we recommend biologic mesh repair in these cases if the defect is large.

    View details for DOI 10.1016/j.ijscr.2014.10.088

    View details for PubMedID 25544481

    View details for PubMedCentralID PMC4334998

  • Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi MALARIA JOURNAL Foster, D., Cox-Singh, J., Mohamad, D. S., Krishna, S., Chin, P. P., Singh, B. 2014; 13


    Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, infects humans and can cause fatal malaria. It is difficult to diagnose by microscopy because of morphological similarity to Plasmodium malariae. Nested PCR assay is the most accurate method to distinguish P. knowlesi from other Plasmodium species but is not cost effective in resource-poor settings. Rapid diagnostic tests (RDTs) are recommended for settings where malaria is prevalent. In this study, the effectiveness of three RDTs in detecting P. knowlesi from fresh and frozen patient blood samples was evaluated.Forty malaria patients (28 P. knowlesi, ten P. vivax and two P. falciparum) diagnosed by microscopy were recruited in Sarawak, Malaysian Borneo during a 16-month period. Patient blood samples were used to determine parasitaemia by microscopy, confirm the Plasmodium species present by PCR and evaluate three RDTs: OptiMAL-IT, BinaxNOW® Malaria and Paramax-3. The RDTs were also evaluated using frozen blood samples from 41 knowlesi malaria patients.OptiMAL-IT was the most sensitive RDT, with a sensitivity of 71% (20/28; 95% CI = 54-88%) for fresh and 73% (30/41; 95% CI = 59-87%) for frozen knowlesi samples. However, it yielded predominantly falciparum-positive results due to cross-reactivity of the P. falciparum test reagent with P. knowlesi. BinaxNOW® Malaria correctly detected non-P. falciparum malaria in P. knowlesi samples but was the least sensitive, detecting only 29% (8/28; 95% CI = 12-46%) of fresh and 24% (10/41; 95% CI = 11-37%) of frozen samples. The Paramax-3 RDT tested positive for P. vivax with PCR-confirmed P. knowlesi samples with sensitivities of 40% (10/25; 95% CI = 21-59%) with fresh and 32% (13/41; 95% CI = 17-46%) with frozen samples. All RDTs correctly identified P. falciparum- and P. vivax-positive controls with parasitaemias above 2,000 parasites/μl blood.The RDTs detected Plasmodium in P. knowlesi-infected blood samples with poor sensitivity and specificity. Patients with P. knowlesi could be misdiagnosed as P. falciparum with OptiMAL-IT, P. vivax with Paramax-3 and more correctly as non-P. vivax/non-P. falciparum with BinaxNOW® Malaria. There is a need for a sensitive and specific RDT for malaria diagnosis in settings where P. knowlesi infections predominate.

    View details for DOI 10.1186/1475-2875-13-60

    View details for Web of Science ID 000332774300003

    View details for PubMedID 24548805

    View details for PubMedCentralID PMC3931291

  • Ex vivo Evans blue assessment of the blood brain barrier in three breast cancer brain metastasis models. Breast cancer research and treatment Do, J., Foster, D., Renier, C., Vogel, H., Rosenblum, S., Doyle, T. C., Tse, V., Wapnir, I. 2014; 144 (1): 93-101


    The limited entry of anticancer drugs into the central nervous system represents a special therapeutic challenge for patients with brain metastases and is primarily due to the blood brain barrier (BBB). Albumin-bound Evans blue (EB) dye is too large to cross the BBB but can grossly stain tissue blue when the BBB is disrupted. The course of tumor development and the integrity of the BBB were studied in three preclinical breast cancer brain metastasis (BCBM) models. A luciferase-transduced braintropic clone of MDA-231 cell line was used. Nude mice were subjected to stereotactic intracerebral inoculation, mammary fat pad-derived tumor fragment implantation, or carotid artery injections. EB was injected 30 min prior to euthanasia at various timepoints for each of the BCBM model animals. Serial bioluminescent imaging demonstrated exponential tumor growth in all models. Carotid BCBM appeared as diffuse multifocal cell clusters. EB aided the localization of metastases ex vivo. Tumor implants stained blue at 7 days whereas gross staining was not evident until day 14 in the stereotactic model and day 28 for the carotid model. EB assessment of the integrity of the BBB provides useful information relevant to drug testing in preclinical BCBM models.

    View details for DOI 10.1007/s10549-014-2854-5

    View details for PubMedID 24510011

  • Two treatments, one disease: childhood malaria management in Tanga, Tanzania MALARIA JOURNAL Foster, D., Vilendrer, S. 2009; 8


    In the Tanga District of coastal Tanzania, malaria is one of the primary causes of mortality for children under the age of five. While some children are treated with malaria medications in biomedical facilities, as the World Health Organization recommends, others receive home-care or treatment from traditional healers. Recognition of malaria is difficult because symptoms can range from fever with uncomplicated malaria to convulsions with severe malaria. This study explores why caregivers in the Tanga District of Tanzania pursue particular courses of action to deal with malaria in their children.Qualitative data were collected through interviews with three samples: female caregivers of children under five (N = 61), medical practitioners (N = 28), and traditional healers (N = 18) in urban, peri-urban, and rural areas. The female caregiver sample is intentionally stratified to reflect the greater population of the Tanga District in level of education, marital status, gender of household head, religion, and tribal group affiliation. Qualitative data were counted, coded and analysed using NVivo7 software.Results indicate that a variety of factors influence treatment choice, including socio-cultural beliefs about malaria symptoms, associations with spiritual affliction requiring traditional healing, knowledge of malaria, and fear of certain anti-malaria treatment procedures. Most notably, some caregivers identified convulsions as a spiritual condition, unrelated to malaria. While nearly all caregivers reported attending biomedical facilities to treat children with fever (N = 60/61), many caregivers stated that convulsions are best treated by traditional healers (N = 26/61). Qualitative interviews with medical practitioners and traditional healers confirmed this belief.Results offer insight into current trends in malaria management and have implications in healthcare policy, educational campaigns, and the importance of integrating traditional and biomedical approaches.

    View details for DOI 10.1186/1475-2875-8-240

    View details for Web of Science ID 000272254600001

    View details for PubMedID 19860900

    View details for PubMedCentralID PMC2779815