Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a p... more Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a potential alternative to using genomic DNA from invasive tissue biopsies. In this study, we developed a custom melanoma next-generation sequencing (NGS) panel which includes 123 amplicons in 30 genes covering driver and targetable mutations and alterations associated with treatment resistance. Analysis of a cohort of 74 stage III and IV treatment-naïve melanoma patients revealed that sensitivity of ctDNA detection was influenced by the amount of circulating-free DNA (cfDNA) input and stage of melanoma. At the recommended cfDNA input quantity of 20 ng (available in 28/74 patients), at least one cancer-associated mutation was detected in the ctDNA of 84% of stage IV patients and 47% of stage III patients with a limit of detection for mutant allele frequency (MAF) of 0.2%. This custom melanoma panel showed significant correlation with droplet digital PCR (ddPCR) and provided a more comprehen...
Interplay between the dependence of symmetry energy on density and the variation of nucleonic den... more Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula. Charge symmetry of the nuclear interactions allows to introduce isoscalar and isovector densities that are approximately independent of the magnitude of neutron-proton asymmetry.
Falls are common among the elderly population. Examinations for the cause of falls are usually mu... more Falls are common among the elderly population. Examinations for the cause of falls are usually mundane, but may be challenging, leading to surprising diagnoses. We report on a previously healthy elderly man who presented with repeated falls and rapidly progressive limitations in mobility, in addition to a stutter. Neuroimaging was particularly helpful for making the diagnosis in this patient.
This essay argues that neo-racism undermines the U.S.’s role as a global leader in higher educati... more This essay argues that neo-racism undermines the U.S.’s role as a global leader in higher education, considering the risks to public health, personal freedoms, and rights. With the rise of national protectionism, universities are and must remain international. Knowledge is fundamentally borderless, and yet higher education is being bordered by neo-racism. Neo-racist barriers to international migration, collaboration, and exchange limit higher education as well as our universities. Neo-racism limits our freedoms, it limits our rights, and now limits our ability to respond to COVID-19 effectively. Neo-racist barriers must be called out and addressed.
Proceedings of the International Symposium on Human Factors and Ergonomics in Health Care, 2020
The purpose of this work is to obtain a set of best practices for the design of mental health sma... more The purpose of this work is to obtain a set of best practices for the design of mental health smartphone applications (MHSAs) for an adolescent user base. The authors carried out a systematic literature review combined with a bibliographic coupling analysis to identify relevant literature, and then a thematic analysis of the literature to identify core principles. These efforts led to a framework of nine general principles for the creation and design of MHSAs. The nine core principles identified were: Using evidence-based treatments, encouraging intrinsic motivation in users, using extrinsic behavior triggers, providing professional support, enabling social support, engaging users during the development process, using user-centered design principles, including a parental mode, and protecting patients’ privacy.
The 21-gene Oncotype DX recurrence score (RS) assay quantifies risk of distant recurrence and pre... more The 21-gene Oncotype DX recurrence score (RS) assay quantifies risk of distant recurrence and predicts benefit from chemotherapy in tamoxifen-treated estrogen receptor (ER)-positive, node-negative breast cancer. Although clinically useful, the assay costs roughly $4650. Because the assay is weighted heavily towards expression of ER, our objective was to determine its clinical utility in strongly ER-positive tumors. This was a retrospective study of Huntington Hospital patients undergoing an Oncotype DX assay between 2007 and 2010. Data collected included patient age, expression of ER, progesterone receptor (PR), HER2/neu, ki67, and p53, tumor size, node status, lymphovascular invasion, and nuclear grade. Of 133 total patients, 84 (63.2%) had strongly ER-positive tumors (≥90% expression). Only seven of 84 patients (8.3%) had a high risk RS (>30), indicating statistically significant predicted benefit from chemotherapy. All seven had intermediate to high ki67 expression (>20%) a...
ISPRS International Journal of Geo-Information, 2020
Identification of neighborhoods is an important, financially-driven topic in real estate. It is k... more Identification of neighborhoods is an important, financially-driven topic in real estate. It is known that the real estate industry uses ZIP (postal) codes and Census tracts as a source of land demarcation to categorize properties with respect to their price. These demarcated boundaries are static and are inflexible to the shift in the real estate market and fail to represent its dynamics, such as in the case of an up-and-coming residential project. Delineated neighborhoods are also used in socioeconomic and demographic analyses where statistics are computed at a neighborhood level. Current practices of delineating neighborhoods have mostly ignored the information that can be extracted from property appraisals. This paper demonstrates the potential of using only the distance between subjects and their comparable properties, identified in an appraisal, to delineate neighborhoods that are composed of properties with similar prices and features. Using spatial filters, we first identify...
Changes in DNA methylation are well documented in cancer development and progression and are typi... more Changes in DNA methylation are well documented in cancer development and progression and are typically identified through analyses of genomic DNA. The capability of monitoring tumor-specific methylation changes in circulating tumor DNA (ctDNA) has the potential to improve the sensitivity of ctDNA for the diagnosis and prognosis of solid tumors. In this study we profiled the methylation of seven gene targets (all known to be hypermethylated in metastatic melanoma) within the plasma of patients with advanced melanoma using amplicon-based next generation sequencing of bisulfite-treated DNA. Hypermethylation of 6/7 gene targets, including paraoxonase 3 (PON3) was significantly elevated in patients with metastatic melanoma (n = 4) compared to healthy control samples (n = 5). In addition, the degree of hypermethylation of PON3 and MEOX2 were significantly correlated with ctDNA copy number in melanoma patients, confirming the utility of methylated ctDNA in the absence of tumor mutation dat...
BACKGROUND & AIMS Mild cognitive impairment (MCI) patients are at risk of cognitive decline, ... more BACKGROUND & AIMS Mild cognitive impairment (MCI) patients are at risk of cognitive decline, while elevated serum homocysteine is also associated with cognitive impairment. Thus, older people with MCI and hyperhomocysteinemia may be under greater risk of cognitive decline. We therefore performed a randomized trial of homocysteine-lowering by B vitamins supplementation to prevent cognitive decline in older MCI patients with elevated serum homocysteine. METHODS 279 MCI outpatients aged ≥65 years with serum homocysteine ≥10.0 μmol/L were randomly assigned to take either methylcobalamin 500 μg and folic acid 400 μg once daily, or two placebo tablets for 24 months. All subjects were followed up at 12 monthly intervals. The primary outcome was cognitive decline as defined by an increase in clinical dementia rating scale (CDR) sum of boxes (CDR_SOB). The secondary outcomes were global CDR, memory Z score, executive function Z score and Hamilton depression rating scale (HDRS) score. RESULTS The clinical characteristics between two groups were well matched, except that the supplement group had better executive function. The supplement effectively lowered serum homocysteine (mean 13.9 ± sd 3.5 μmol at baseline to 9.3 ± 2.4 μmol/L at month 24). At month 24, there was no significant group difference in CDR_SOB or any secondary outcomes (mean changes in CDR_SOB 0.36 versus 0.22 in supplement and placebo groups respectively). At month 12, the supplement group significantly improved in executive function and had lower HDRS score (P = 0.004 and 0.012 respectively). Group difference was significant for HDRS, but borderline significant for executive function. (P = 0.01; 0.06 respectively) These effects were not significant at month 24. Subgroup analysis showed that aspirin use had significant interaction with B supplements in CDR_SOB at month 24 (Beta 0.189, P = 0.005). CONCLUSIONS Vitamin B12 and folic acid supplementation did not reduce cognitive decline in older people with MCI and elevated serum homocysteine, though the cognitive decline over two years in placebo group was small. The supplement led to a significant reduction in depressive symptoms at month 12, though this effect was not sustained. Aspirin use had a negative interaction effect on cognitive functioning with B supplements. CLINICAL TRIAL REGISTRATION Centre for Clinical Research and Biostatistics (CCRB) Clinical Trials Registry: CUHK_CCT00373.
This study critically examines the self-reported experiences of international graduate students u... more This study critically examines the self-reported experiences of international graduate students using a framework understanding internationalization as acquisitions and mergers. Students reported positive experiences with their advisors. However, students’ accounts of laboratories and other research settings were diverse, ranging from co-contributors to knowledge and respected collaborators to employed cheap labor that their advisors depended upon for their own gains. In some cases, these students feared that their funding would be cut off or dismissed from the program (and consequently deported from the US) if they challenged their advisors. Whether such apprehensions were valid is unknown as this study focused on perceptions of the students only. The findings do lead to important future directions for research and practice.
Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a p... more Detection of melanoma-associated mutations using circulating tumor DNA (ctDNA) from plasma is a potential alternative to using genomic DNA from invasive tissue biopsies. In this study, we developed a custom melanoma next-generation sequencing (NGS) panel which includes 123 amplicons in 30 genes covering driver and targetable mutations and alterations associated with treatment resistance. Analysis of a cohort of 74 stage III and IV treatment-naïve melanoma patients revealed that sensitivity of ctDNA detection was influenced by the amount of circulating-free DNA (cfDNA) input and stage of melanoma. At the recommended cfDNA input quantity of 20 ng (available in 28/74 patients), at least one cancer-associated mutation was detected in the ctDNA of 84% of stage IV patients and 47% of stage III patients with a limit of detection for mutant allele frequency (MAF) of 0.2%. This custom melanoma panel showed significant correlation with droplet digital PCR (ddPCR) and provided a more comprehen...
Interplay between the dependence of symmetry energy on density and the variation of nucleonic den... more Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula. Charge symmetry of the nuclear interactions allows to introduce isoscalar and isovector densities that are approximately independent of the magnitude of neutron-proton asymmetry.
Falls are common among the elderly population. Examinations for the cause of falls are usually mu... more Falls are common among the elderly population. Examinations for the cause of falls are usually mundane, but may be challenging, leading to surprising diagnoses. We report on a previously healthy elderly man who presented with repeated falls and rapidly progressive limitations in mobility, in addition to a stutter. Neuroimaging was particularly helpful for making the diagnosis in this patient.
This essay argues that neo-racism undermines the U.S.’s role as a global leader in higher educati... more This essay argues that neo-racism undermines the U.S.’s role as a global leader in higher education, considering the risks to public health, personal freedoms, and rights. With the rise of national protectionism, universities are and must remain international. Knowledge is fundamentally borderless, and yet higher education is being bordered by neo-racism. Neo-racist barriers to international migration, collaboration, and exchange limit higher education as well as our universities. Neo-racism limits our freedoms, it limits our rights, and now limits our ability to respond to COVID-19 effectively. Neo-racist barriers must be called out and addressed.
Proceedings of the International Symposium on Human Factors and Ergonomics in Health Care, 2020
The purpose of this work is to obtain a set of best practices for the design of mental health sma... more The purpose of this work is to obtain a set of best practices for the design of mental health smartphone applications (MHSAs) for an adolescent user base. The authors carried out a systematic literature review combined with a bibliographic coupling analysis to identify relevant literature, and then a thematic analysis of the literature to identify core principles. These efforts led to a framework of nine general principles for the creation and design of MHSAs. The nine core principles identified were: Using evidence-based treatments, encouraging intrinsic motivation in users, using extrinsic behavior triggers, providing professional support, enabling social support, engaging users during the development process, using user-centered design principles, including a parental mode, and protecting patients’ privacy.
The 21-gene Oncotype DX recurrence score (RS) assay quantifies risk of distant recurrence and pre... more The 21-gene Oncotype DX recurrence score (RS) assay quantifies risk of distant recurrence and predicts benefit from chemotherapy in tamoxifen-treated estrogen receptor (ER)-positive, node-negative breast cancer. Although clinically useful, the assay costs roughly $4650. Because the assay is weighted heavily towards expression of ER, our objective was to determine its clinical utility in strongly ER-positive tumors. This was a retrospective study of Huntington Hospital patients undergoing an Oncotype DX assay between 2007 and 2010. Data collected included patient age, expression of ER, progesterone receptor (PR), HER2/neu, ki67, and p53, tumor size, node status, lymphovascular invasion, and nuclear grade. Of 133 total patients, 84 (63.2%) had strongly ER-positive tumors (≥90% expression). Only seven of 84 patients (8.3%) had a high risk RS (>30), indicating statistically significant predicted benefit from chemotherapy. All seven had intermediate to high ki67 expression (>20%) a...
ISPRS International Journal of Geo-Information, 2020
Identification of neighborhoods is an important, financially-driven topic in real estate. It is k... more Identification of neighborhoods is an important, financially-driven topic in real estate. It is known that the real estate industry uses ZIP (postal) codes and Census tracts as a source of land demarcation to categorize properties with respect to their price. These demarcated boundaries are static and are inflexible to the shift in the real estate market and fail to represent its dynamics, such as in the case of an up-and-coming residential project. Delineated neighborhoods are also used in socioeconomic and demographic analyses where statistics are computed at a neighborhood level. Current practices of delineating neighborhoods have mostly ignored the information that can be extracted from property appraisals. This paper demonstrates the potential of using only the distance between subjects and their comparable properties, identified in an appraisal, to delineate neighborhoods that are composed of properties with similar prices and features. Using spatial filters, we first identify...
Changes in DNA methylation are well documented in cancer development and progression and are typi... more Changes in DNA methylation are well documented in cancer development and progression and are typically identified through analyses of genomic DNA. The capability of monitoring tumor-specific methylation changes in circulating tumor DNA (ctDNA) has the potential to improve the sensitivity of ctDNA for the diagnosis and prognosis of solid tumors. In this study we profiled the methylation of seven gene targets (all known to be hypermethylated in metastatic melanoma) within the plasma of patients with advanced melanoma using amplicon-based next generation sequencing of bisulfite-treated DNA. Hypermethylation of 6/7 gene targets, including paraoxonase 3 (PON3) was significantly elevated in patients with metastatic melanoma (n = 4) compared to healthy control samples (n = 5). In addition, the degree of hypermethylation of PON3 and MEOX2 were significantly correlated with ctDNA copy number in melanoma patients, confirming the utility of methylated ctDNA in the absence of tumor mutation dat...
BACKGROUND & AIMS Mild cognitive impairment (MCI) patients are at risk of cognitive decline, ... more BACKGROUND & AIMS Mild cognitive impairment (MCI) patients are at risk of cognitive decline, while elevated serum homocysteine is also associated with cognitive impairment. Thus, older people with MCI and hyperhomocysteinemia may be under greater risk of cognitive decline. We therefore performed a randomized trial of homocysteine-lowering by B vitamins supplementation to prevent cognitive decline in older MCI patients with elevated serum homocysteine. METHODS 279 MCI outpatients aged ≥65 years with serum homocysteine ≥10.0 μmol/L were randomly assigned to take either methylcobalamin 500 μg and folic acid 400 μg once daily, or two placebo tablets for 24 months. All subjects were followed up at 12 monthly intervals. The primary outcome was cognitive decline as defined by an increase in clinical dementia rating scale (CDR) sum of boxes (CDR_SOB). The secondary outcomes were global CDR, memory Z score, executive function Z score and Hamilton depression rating scale (HDRS) score. RESULTS The clinical characteristics between two groups were well matched, except that the supplement group had better executive function. The supplement effectively lowered serum homocysteine (mean 13.9 ± sd 3.5 μmol at baseline to 9.3 ± 2.4 μmol/L at month 24). At month 24, there was no significant group difference in CDR_SOB or any secondary outcomes (mean changes in CDR_SOB 0.36 versus 0.22 in supplement and placebo groups respectively). At month 12, the supplement group significantly improved in executive function and had lower HDRS score (P = 0.004 and 0.012 respectively). Group difference was significant for HDRS, but borderline significant for executive function. (P = 0.01; 0.06 respectively) These effects were not significant at month 24. Subgroup analysis showed that aspirin use had significant interaction with B supplements in CDR_SOB at month 24 (Beta 0.189, P = 0.005). CONCLUSIONS Vitamin B12 and folic acid supplementation did not reduce cognitive decline in older people with MCI and elevated serum homocysteine, though the cognitive decline over two years in placebo group was small. The supplement led to a significant reduction in depressive symptoms at month 12, though this effect was not sustained. Aspirin use had a negative interaction effect on cognitive functioning with B supplements. CLINICAL TRIAL REGISTRATION Centre for Clinical Research and Biostatistics (CCRB) Clinical Trials Registry: CUHK_CCT00373.
This study critically examines the self-reported experiences of international graduate students u... more This study critically examines the self-reported experiences of international graduate students using a framework understanding internationalization as acquisitions and mergers. Students reported positive experiences with their advisors. However, students’ accounts of laboratories and other research settings were diverse, ranging from co-contributors to knowledge and respected collaborators to employed cheap labor that their advisors depended upon for their own gains. In some cases, these students feared that their funding would be cut off or dismissed from the program (and consequently deported from the US) if they challenged their advisors. Whether such apprehensions were valid is unknown as this study focused on perceptions of the students only. The findings do lead to important future directions for research and practice.
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