Kenneth Pritzker

Kenneth Pritzker
University of Toronto | U of T · Department of Laboratory Medicine and Pathobiology

MD FRCPC
Tissue interactions with Ultrasound, Inflammation, Novel diagnostics, Fullerinols, Abiotic stress, Medtech Startups

About

359
Publications
55,665
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11,271
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Additional affiliations
July 1972 - August 2013
Mount Sinai Hospital, Toronto
Position
  • Pathologist,

Publications

Publications (359)
Article
From ancient times to the present day, gout has been associated in the popular and scientific literature with wealthy men who overindulge in fancy foods, fine wine, and debauchery. Curiously, amongst diseases, gout was thought to be good, a malady to be accepted because of otherwise beneficial effects on health, and longevity. This narrative review...
Preprint
Full-text available
Ultrasonic cavitation is being used in medical applications as a way to influence matter, such as tissue or drug vehicles, on a micro-scale. Oscillating or collapsing cavitation bubbles provide transient mechanical force fields, which can, e.g., fractionate soft tissue or even disintegrate solid objects such as calculi. Our recent study demonstrate...
Preprint
Full-text available
Non-invasive therapeutic ultrasound methods, such as high-intensity focused ultrasound (HIFU), have limited access to tissue targets shadowed by bones or presence of gas. This study demonstrates that an ultrasonically actuated medical needle can be used to translate nanoparticles and fluids under the action of nonlinear phenomena, potentially overc...
Article
Full-text available
Despite the ubiquitous use over the past 150 years, the functions of the current medical needle are facilitated only by mechanical shear and cutting by the needle tip, i.e. the lancet. In this study, we demonstrate how nonlinear ultrasonics (NLU) extends the functionality of the medical needle far beyond its present capability. The NLU actions were...
Article
Introduction Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to deve...
Article
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The heterogeneity of colon cancers and their reactions presents both a challenge and promise for personalized medicine. The challenge is to develop effective biologically personalized therapeutics guided by predictive and prognostic biomarkers. Presently, there are several classes of candidate biomarkers, including genomic probes, inhibitory RNAs,...
Poster
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Medical needles play a central role in everyday healthcare, exemplified by the 16 billion injections applied worldwide every year. Despite the broad use, medical needles still present substantial functional limitations related to pain, precision, localization as well as drug and cell delivery. Limited literature exists on reporting nonlinear acou...
Poster
Full-text available
Fine needle aspiration biopsy (FNAB) is a common minimally invasive tissue sampling procedure used in diagnostics, especially in cancer management. Its limitations are to a major part associated with the insufficiency of the tissue yield, which can lead to inconclusive diagnoses in 9-34% of FNABs. In this work, we demonstrate the capability of an u...
Preprint
Full-text available
Despite the ubiquitous use over the past 150 years, the functions of the current medical needle are facilitated only by mechanical shear and cutting by the needle tip, i.e. the lancet. In this study, we demonstrate how nonlinear ultrasonics (NLU) extends the functionality of the medical needle far beyond its present capability. The NLU actions were...
Chapter
Pharmacologic management for articular cartilage injury and osteoarthritis (OA) should always be considered as supplemental to conservative approaches related to physical and/or rehabilitative exercises. This is especially true for children whose cartilage has intrinsic potential for healing. Pharmacologic agents can be administered for pain relief...
Chapter
Histopathological evaluation of cartilage by standardized methods is the current most accurate means of evaluating disease type and extent within cartilage. Correlations between cartilage histology and biomechanical properties extend histopathology to be a surrogate for biomechanical dysfunction. However, except at arthroplasty, clinical assessment...
Chapter
The unique structure of articular cartilage provides the intrinsic functional properties that enable the knee joint to withstand and resist excessive compressive and biomechanical loads, facilitating almost frictionless knee movement. This chapter outlines the architectural and compositional features of articular cartilage. The relationships of cho...
Chapter
Synovial fluid, blood, and urine biomarkers for articular cartilage function have been long sought as these markers are potentially more sensitive than clinical imaging to offer prognosis with respect to disease evolution and response to therapy. Many different biomarkers have been investigated including fragments of proteoglycans, collagens, and n...
Chapter
Aging implies changes in articular cartilage cells and the surrounding extracellular matrix (ECM) that are reflective of metabolic changes related to time alone. For chondrocytes, these are genomic and intracytoplasmic changes that lessen their capacity to respond and control their extracellular environment; for the matrix, these are changes that l...
Chapter
Lifestyle modification and active physical therapy have been shown to be efficacious in cartilage repair following injury in reducing symptoms and possibly reducing disease progression to osteoarthritis (OA). Weight loss and moderate exercise are the most effective lifestyle modification modalities. Exercise can be classified as low impact exercise...
Chapter
Articular cartilage serves as a lubricated, wear-resistant, friction-reducing self-maintaining material that is slightly compressible to evenly distribute forces onto the bone. Articular cartilage macromolecular composition and architecture and its biomechanical properties are well adapted to withstand mechanical loads increasingly for a ten-decade...
Article
Full-text available
OBJECTIVE To develop and validate a machine learning (ML) approach for automatic three-dimensional (3D) histopathological grading of osteochondral samples imaged with contrast-enhanced micro-computed tomography (CEμCT). DESIGN A total of 79 osteochondral cores from 24 total knee arthroplasty patients and 2 asymptomatic donors were imaged using CEμ...
Article
Full-text available
Background: Little is known about the mechanisms underlying the clinical overlap between gut inflammation and joint ankylosis, as exemplified by the concurrence of inflammatory bowel diseases (IBD) and ankylosing spondylitis (AS). As dysbiosis may serve as a common contributor, the anti-microbial pleiotropic factor lipocalin 2 could be a potential...
Book
Covering both pediatric and adult populations, this comprehensive text covers the diverse topics related to the health, disease and therapy of articular cartilage of the knee, from basic principles to future directions for research. This vast array of information is arranged into eight sections, encompassing a number of relevant disciplines and cov...
Article
Full-text available
Background: Assessment of the efficacy of a multi-agent chemotherapy protocol in which cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) are administered in canine lymphoma is generally performed by physical measurement of lymph node diameter. However, no consistent correlation has been made with prognostic indicators and the length...
Article
Full-text available
Localized delivery of drugs into an osteoarthritic cartilaginous lesion does not yet exist, which limits pharmaceutical management of osteoarthritis (OA). High-intensity focused ultrasound (HIFU) provides a means to actuate matter from a distance in a non-destructive way. In this study, we aimed to deliver methylene blue locally into bovine articul...
Article
Full-text available
The aim of this study was to quantify sub-resolution trabecular bone morphometrics, which are also related to osteoarthritis (OA), from clinical resolution cone beam computed tomography (CBCT). Samples (n = 53) were harvested from human tibiae (N = 4) and femora (N = 7). Grey-level co-occurrence matrix (GLCM) texture and histogram-based parameters...
Preprint
Full-text available
Objective: To develop and validate a machine learning (ML) approach for automatic three-dimensional (3D) histopathological grading of osteochondral samples imaged with contrast-enhanced micro-computed tomography (CEμCT). Design: Osteochondral cores from 24 total knee arthroplasty patients and 2 asymptomatic cadavers (n = 34, ϕ = 2 mm; n = 45, ϕ = 4...
Article
Full-text available
Context.—: Needle biopsy of diseased tissue is an essential diagnostic tool that is becoming even more important as precision medicine develops. However, the capability of this modality to efficiently provide samples adequate for diagnostic and prognostic analysis remains quite limited relative to current diagnostic needs. For physicians and patie...
Poster
Full-text available
Ultrasound is widely used in various diagnostic, therapeutic and drug delivery applications. The aim of this study was to establish (i) an experimental arrangement to study ultrasonic drug delivery in the presence of acoustic cavitation near an ultrasonically actuated needle, (ii) quantify the bubble activity near the needle and (iii) show the deli...
Article
Purpose In suspected spondylodiscitis and vertebral osteomyelitis, computed tomography (CT)-guided biopsies are often performed to determine a causative organism and guide antimicrobial therapy. The aim of this study is to determine the diagnostic culture yield of CT-guided biopsies performed in cases of suspected spinal infections. Methods A lite...
Article
Full-text available
One of the earliest changes in osteoarthritis (OA) is a surface discontinuity of the articular cartilage (AC), and these surface changes become gradually more complex with OA progression. We recently developed a contrast enhanced micro‐computed tomography (µCT) method for visualizing AC surface in detail. The present study aims to introduce a µCT a...
Article
The in vitro process of chondrogenic differentiation of mesenchymal stem cells (MSCs) induces a pre-apoptotic hypertrophic phenotype, guided by the active status of the WNT/β‑catenin pathway. To achieve a stable chondrocyte phenotype for cartilage tissue engineering, it is necessary to gain a better understanding of specific genes that regulate the...
Article
Full-text available
Localized delivery of drugs into articular cartilage (AC) may facilitate the development of novel therapies to treat osteoarthritis (OA). We investigated the potential of spark-gap-generated sound to deliver a drug surrogate, i.e., methylene blue (MB), into AC. In vitro experiments exposed bovine AC samples to either simultaneous sonication and imm...
Article
Full-text available
Objective: Our aim is to establish methods for quantifying morphometric properties of calcified cartilage from micro-computed tomography (μCT). Furthermore, we evaluated the feasibility of these methods in investigating relationships between osteoarthritis (OA), tidemark surface morphology and open subchondral channels. Method: Samples (n=15) us...
Article
Full-text available
Objective: The aims of this study were: to 1) develop a novel sample processing protocol to visualize human articular cartilage (AC) chondrons using micro-computed tomography (μCT), 2) develop and validate an algorithm to quantify the chondron morphology in 3D, and 3) compare the differences in chondron morphology between intact and osteoarthritic...
Data
Comparison of histology sections (left) and μCT volume (slice-by-slice presentation, right) in osteochonral tissue with OARSI grade 4.
Data
Comparison of histology sections (left) and μCT volume (slice-by-slice presentation, right) in osteochonral tissue with OARSI grade 4.5.
Article
Full-text available
Contrast-enhanced micro-computed tomography (CEμCT) with cationic and anionic contrast agents reveals glycosaminoglycan (GAG) content and distribution in articular cartilage (AC). The advantage of using cationic stains (e.g., CA4+) compared to anionic stains (e.g., Hexabrix®), is that it distributes proportionally with GAGs, while anionic stain dis...
Article
Full-text available
Research is ongoing to develop drug therapies to manage osteoarthritis (OA) and articular cartilage (AC) injuries. However, means to deliver drug to localized AC lesions are highly limited and not clinically available. This study investigates the capability of laser ultrasound (laser-induced plasma sound source) to deliver agents (methylene blue, M...
Article
Full-text available
Objective Histopathological grading of osteochondral (OC) tissue is widely used in osteoarthritis (OA) research, and it is relatively common in post-surgery in vitro diagnostics. However, relying on thin tissue section, this approach includes a number of limitations, such as: (i) destructiveness, (ii) sample processing artefacts, (iii) 2D section d...
Article
Objectives: Straticyte™ was previously shown to be a more effective prognostic assessment than the current standard of care, histopathological dysplasia grading, to assess progression risk of oral epithelial dysplasia to invasive cancer [Hwang JT, Gu YR, Shen M, Ralhan R, Walfish PG, Pritzker KP, et al. Individualized five-year risk assessment for...
Data
Figure S1. Demonstration of the LBP‐based method. Figure S2. Correlation between OARSI grade and histologically defines thicknesses of different osteochondral tissues: In upper row thicknesses of cartilage and calcified cartilage on left and right respectively. Table S1. Coefficient of variations for subchondral plate and trabecular bone structur...
Article
Full-text available
Contrast-enhanced micro-computed tomography (CEμCT) with phosphotungstic acid (PTA) has shown potential for detecting collagen distribution of articular cartilage. However, the selectivity of the PTA staining to articular cartilage constituents remains to be elucidated. The aim of this study was to investigate the dependence of PTA for the collagen...
Data
Data from depth-wise analyses and statistical tests. Means of the groups (n = 9), standard deviations, and relative changes between enzymatically treated groups and control group are shown in the table. Wilcoxon signed-rank test was used to determine if there were statistically significant difference between the groups. Statistical tests for each d...
Article
Objective: The standard of care for premalignant lesion risk assessment is dysplasia grading by histopathology. With significant overlap between dysplasia grades and high inter- and intraobserver variations, histopathology dysplasia grading alone is not a useful prognostic tool. Our aim is to investigate whether a method for quantitatively assessi...
Article
Full-text available
Despite increasing evidence that subchondral bone contributes to OA pathogenesis, little is known about local changes in bone structure compared to cartilage degeneration. This study linked structural adaptation of subchondral bone with histological osteoarthritis grade. Twenty five osteochondral samples of macroscopically different degeneration we...
Article
Full-text available
Background Cellular stressors and apoptosis-inducing agents have been shown to induce ribosomal RNA (rRNA) degradation in eukaryotic cells. Recently, RNA degradation in vivo was observed in patients with locally advanced breast cancer, where mid-treatment tumor RNA degradation was associated with complete tumor destruction and enhanced patient surv...
Data
Supplemental Table 1: Multivariate discriminant analysis revealing the ability of multiple variables (total epirubicin dose, total docetaxel dose, and the dose schedule) to significantly affect disease-free survival, when used in combination (Wald test). In single factor analysis, patients with tumor RDI values >50 had significantly greater DFS tha...
Article
Full-text available
In a prior substudy of the CAN-NCIC-MA.22 clinical trial (ClinicalTrials.gov identifier NCT00066443), we observed that neoadjuvant chemotherapy reduced tumor RNA integrity in breast cancer patients, a phenomenon we term "RNA disruption." The purpose of the current study was to assess in the full patient cohort the relationship between mid-treatment...
Article
Full-text available
While both prognostic and predictive cancer biomarkers predict clinical outcome, the term ‘predictive biomarker’ is reserved for the association of a specific therapy with a specific clinical outcome. The advent of genomic signatures and next generation sequencing as candidate predictive biomarkers has led to lengthy and expensive processes for bio...
Article
Full-text available
Collagen distribution within articular cartilage (AC) is typically evaluated from histological sections, e.g., using collagen staining and light microscopy. Unfortunately, all techniques based on histological sections are time-consuming, destructive, and without extraordinary effort, limited to two dimensions. This study investigates whether phosph...
Article
Full-text available
Background: As there is now evidence that switching clinical nonresponders early in primary systemic therapy to alternate treatment regimens can enhance survival in some breast cancer patients, the need for a robust intermediate endpoint that can guide treatment response across all tumor subtypes is urgent. Recently, chemotherapy drugs have been sh...