Publications by authors named "Ernest Lam"

Purpose: Circulating tumor cell (CTC)-based (HER2) assay is a laboratory test developed by Epic Sciences using single-cell genomics to detect (HER2) amplification in CTCs found in the peripheral blood of metastatic breast cancer (MBC) patients.

Patients And Methods: Peripheral blood was collected in Streck tubes and centrifugation was used to remove plasma and red blood cells. The remaining nucleated cells were deposited on glass slides, immunofluorescent-stained with proprietary antibodies, scanned by a high-definition digital scanner, and analyzed by a proprietary algorithm.

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Objective: The present study evaluated the in vivo musculoaponeurotic architecture of the superficial head (SH) of the masseter muscle (MM) of asymptomatic participants in excursive mandibular movements compared to the relaxed state as examined with ultrasonography. It was hypothesized that the mean fiber bundle length (FBL) and mean height of the aponeurosis (HA) of the laminae of the SH would differ significantly between the relaxed state and protrusion, ipsilateral excursion, and contralateral excursion.

Study Design: The MM was studied volumetrically in 12 female and 12 male asymptomatic participants bilaterally by using ultrasound imaging.

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Background: For patients with mCRPC, PSMA-targeted radioligand treatment has significantly improved the clinical outcome. A blood-based liquid biopsy assay for recognizing PSMA protein expression on circulating tumor cells may be beneficial for better informing therapeutic decision-making and identifying the patients most likely to benefit from PSMA-targeted radioligand therapy.

Methods: Using high-throughput imaging and digital AI pathology algorithms, a four-color immunofluorescence assay has been developed to find PSMA protein expression on CTCs on a glass slide.

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Objectives: The purpose of this study was to develop protocols that optimize patient radiation dose and image quality for cone beam computed tomographic (CBCT) sialography for the major salivary glands.

Study Design: Radiation absorbed dose measurements were repeated in triplicate using 25 sites in the head and neck of a Radiation ANalog DOsimetry system (RANDO) phantom, and effective doses were calculated across a range of peak kilovoltage (kVp) and milliamperage (mA) settings using an 8 cm (diameter) by 5 cm (height) field of view (FOV) for submandibular imaging and an 8 cm (diameter) by 8 cm (height) FOV for parotid imaging. Image signal difference-to-noise ratio (SDNR) was determined, and the figure-of-merit (FOM), a measure of image quality, was calculated.

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Background: BRCA2 alterations predict for a response to poly-ADP-ribose polymerase inhibition in metastatic castration-resistant prostate cancer (mCRPC). However, detection is hindered by insufficient tumor tissue and low sensitivity of cell-free DNA for detecting copy number loss.

Objective: To evaluate the BRCA2 loss detection using single-cell, shallow whole-genome sequencing (sWGS) of circulating tumor cells (CTCs) in patients with mCRPC.

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Introduction: Periapical images are routinely made in endodontics to support diagnosis and treatment decisions, but conventional imaging may not readily demonstrate inflammatory changes. This study aims to quantify disagreement in the radiologic interpretation of apical periodontitis/rarefying osteitis between 2 expert examiners and to determine if differences exist based on anatomic location.

Methods: We used 1717 pretreatment periapical images made before orthograde endodontic treatment as part of the Predicting Outcomes of Root Canal Treatment (PREDICT) study conducted within the National Dental Practice-Based Research Network.

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This study explores the overnight usage of Chi Wah Learning Commons and The University of Hong Kong Libraries on the same campus. By adopting quantitative research, it investigates students' preferences in these areas and levels of social capital in the library, further, it explores the similarities and differences of user behavior between the university's undergraduate and postgraduate students. Our findings showed that HKUL had not taken full advantage of its prime location and comprehensive collection in the main library, and the full potential of overnight services.

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Regulation of mRNA steady-state levels is important in controlling gene expression particularly in response to environmental stimuli. This allows cells to rapidly respond to environment changes. The highly conserved nonsense-mediated mRNA decay (NMD) pathway was initially identified as a pathway that degrades aberrant mRNAs.

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Objective: In the present study, we sought to investigate the in vivo musculoaponeurotic architecture of the masseter muscle (MM) volumetrically with ultrasound in asymptomatic participants. It was hypothesized that the mean fiber bundle length (FBL) and mean aponeurotic height of laminae of the MM differ significantly between the relaxed state and maximally contracted state upon elevation of the mandible.

Study Design: The MM was investigated volumetrically in 12 male and 12 female asymptomatic participants (mean age, 25.

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Background: With the advent of new ionizing radiation technologies, consideration must be given to the use of radiography in clinical practice. The authors aimed to determine how general dentists obtain oral and maxillofacial images and whether dentists' demographic characteristics and practice environments affect imaging decisions.

Methods: The authors conducted a cross-sectional study using an electronic survey to collect information from general dentists in Ontario, Canada's most populous province.

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Introduction: Artifact reduction (AR) software has been incorporated into some cone-beam computed tomographic (CBCT) systems to reduce the severity of beam hardening (BH) artifacts and improve image quality. This study quantifies BH artifact and evaluates the effectiveness of AR in 2 CBCT systems.

Methods: Palatal roots of Dent-Alike (Dentsply Sirona, Tulsa, OK) teeth were prepared and root filled with gutta-percha and EndoSequence BC Sealer (Brasseler, Savannah, GA).

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Objective: The aim of this study was to determine the prevalence of 2-dimensional and 3-dimensional digital imaging technologies, the methods used by general dentists to limit patient exposure to ionizing radiation, and the impact of dentists' education on imaging technologies and patient dose-reducing techniques.

Study Design: A cross-sectional, web-based survey of all general dentists in Ontario was conducted.

Results: Responses from 1332 (14.

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Some forms of chronic pain are thought to be driven and maintained by nociceptive input, which can drive plasticity within nociceptive pathways. We have previously identified abnormalities along the entire nociceptive pathway in chronic myalgic temporomandibular disorders (mTMD), including the trigeminal nerves, brainstem pathways, and in the thalamus and somatosensory cortex. These data suggest that there is a peripheral nociceptive drive in mTMD, but the source of this nociceptive activity remains unknown.

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The incomplete identification of structural variants (SVs) from whole-genome sequencing data limits studies of human genetic diversity and disease association. Here, we apply a suite of long-read, short-read, strand-specific sequencing technologies, optical mapping, and variant discovery algorithms to comprehensively analyze three trios to define the full spectrum of human genetic variation in a haplotype-resolved manner. We identify 818,054 indel variants (<50 bp) and 27,622 SVs (≥50 bp) per genome.

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We report on the development of a methylation analysis workflow for optical detection of fluorescent methylation profiles along chromosomal DNA molecules. In combination with Bionano Genomics genome mapping technology, these profiles provide a hybrid genetic/epigenetic genome-wide map composed of DNA molecules spanning hundreds of kilobase pairs. The method provides kilobase pair-scale genomic methylation patterns comparable to whole-genome bisulfite sequencing (WGBS) along genes and regulatory elements.

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Article Synopsis
  • Large structural variants (SVs) in the human genome are typically hard to detect with standard sequencing methods, but long-range genome analysis techniques like optical mapping can effectively identify SVs greater than 2 kb in one go.
  • In a study involving 154 individuals from the 1000 Genomes Project, researchers found that large SV patterns closely match the patterns of single nucleotide variations across 86% of the genome, while about 2% show significant structural complexity.
  • The study also revealed previously uncharacterized regions of the genome, including segmental duplications and areas near chromosomes' ends, identifying roughly 60 Mb of unique genomic content missing from the current reference genome, emphasizing the need for diverse population haplotypes to accurately
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The need to accurately identify the complete structural variation profile of genomes is becoming increasingly evident. In contrast to reference-based methods like sequencing or comparative methods like aCGH, optical mapping is a de novo assembly-based method that enables better realization of true genomic structure. It allows for independently detecting balanced and unbalanced structural variants (SVs) from separate alleles and for discovering de novo events.

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Genetic studies of human evolution require high-quality contiguous ape genome assemblies that are not guided by the human reference. We coupled long-read sequence assembly and full-length complementary DNA sequencing with a multiplatform scaffolding approach to produce ab initio chimpanzee and orangutan genome assemblies. By comparing these with two long-read de novo human genome assemblies and a gorilla genome assembly, we characterized lineage-specific and shared great ape genetic variation ranging from single- to mega-base pair-sized variants.

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Introduction: Limited field of view cone-beam computed tomographic (CBCT) imaging has been used to augment clinical testing of vertical root fractures (VRFs); however, the presence of gutta-percha (GP) in the canal space generates substantial imaging artifacts that make fracture detection difficult. The purpose of this study was to evaluate the influence of a zirconium (Zr)-based root filling material with radiologic properties that reduce beam hardening (BH) artifacts using CBCT imaging in the in vitro diagnosis of VRFs.

Methods: One hundred seventy-six single-rooted mandibular premolar teeth were obtained, and half of these teeth were filled with GP or Zr (CPoint; EndoTechnologies, LLC, Shrewsbury, MA).

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Introduction: The beam hardening (BH) artifact produced by root filling materials in cone-beam computed tomographic (CBCT) images is influenced by their radiologic K absorption edge values. The purpose of this study was to describe a novel technique to characterize BH artifacts in CBCT images produced by 3 root canal filling materials and to evaluate the effects of a zirconium (Zr)-based root filling material with a lower K edge (17.99 keV) on the production of BH artifacts.

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We present a new method, OMSV, for accurately and comprehensively identifying structural variations (SVs) from optical maps. OMSV detects both homozygous and heterozygous SVs, SVs of various types and sizes, and SVs with or without creating or destroying restriction sites. We show that OMSV has high sensitivity and specificity, with clear performance gains over the latest method.

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Background: Radiologic assessment of mandibular bone invasion is critical in evaluating the extent of bone resection required in patients with oral cancer. There are a few reports of improved sensitivity with cone-beam CT (CBCT) over conventional CT.

Methods: A prospective cohort study of patients with oral squamous cell carcinomas adjacent to the mandible requiring marginal or segmental mandibular resection was performed.

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The decrease in sequencing cost and increased sophistication of assembly algorithms for short-read platforms has resulted in a sharp increase in the number of species with genome assemblies. However, these assemblies are highly fragmented, with many gaps, ambiguities, and errors, impeding downstream applications. We demonstrate current state of the art for de novo assembly using the domestic goat (Capra hircus) based on long reads for contig formation, short reads for consensus validation, and scaffolding by optical and chromatin interaction mapping.

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Despite tremendous progress in genome sequencing, the basic goal of producing a phased (haplotype-resolved) genome sequence with end-to-end contiguity for each chromosome at reasonable cost and effort is still unrealized. In this study, we describe an approach to performing de novo genome assembly and experimental phasing by integrating the data from Illumina short-read sequencing, 10X Genomics linked-read sequencing, and BioNano Genomics genome mapping to yield a high-quality, phased, de novo assembled human genome.

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