73 research outputs found
Machine Learning Classification of Primary Tissue Origin of Cancer from DNA Methylation Markers
Cancer is one of the leading causes of death globally and was responsible for approximately 9.6 million deaths in 2018. One of the main reason for deaths from cancer is late-stage presentation and inaccessible diagnosis and treatment. Cancer often spreads from the part of the body where it started (primary site) to a different part of the body (metastatic site). Identifying the primary site of cancer plays a key role as it directs the appropriate treatment. Cancer which spreads needs the same treatment as its origin. Having this knowledge can help doctors to decide the type of treatment.
All cancers begin when one or more genes in a cell mutate and create abnormal proteins which cause cells to multiply uncontrollably. Genes are present in the DNA of each cell in human body, and research shows that distinct and abnormal patterns in methylation of DNA are observed in case of cancers. DNA methylation is also considered as an early and fundamental step where normal tissue undergoes transformations. Since DNA methylation is tissue-specific and change with cell differentiation, methylation sites are good markers for identifying tissues of origin.
In this thesis, we propose the use of machine learning techniques to identify the primary sites of cancers to increase the accuracy of diagnosis and treatment.
For this purpose, we implemented various classification algorithms in machine learning like support vector machines, random forests classifier, decision trees, and K nearest neighbor classifier to classify the tumor samples into their tissue origin and compared these models using traditional machine learning metrics. The models are trained and tested on features extracted from the DNA methylation datasets maintained by The Cancer Genome Atlas (TCGA). The experimental results showed that support vector machines could predict the primary sites with 95% training accuracy. The model gave 86% accuracy when tested on a completely independent dataset collected from Gene Expression Omnibus (GEO)
Power Flow Control/Limiting Short Circuit Current Using TCSC
This paper presents the various advantages of Thyristor Controller Series Capacitor (TCSC), both as a Power Flow Controller, as well as a Short Circuit limiter during faults. The results have been derived and verified from the software PSCAD, and the graphs and calculations are included in the paper. The results and information included in the paper are sufficiently accurate. Keywords: Modelling, power system dynamic stability
Parental psychosocial aspects and stressors involved in the management of inborn errors of metabolism.
Parents of children with inborn errors of metabolism (IEM) face numerous psychosocial challenges. An increased understanding and awareness of these stressors can ensure better overall outcomes for the entire family. We conducted semi-structured, in-person interviews with ten parents to identify psychosocial stressors, strategies, and supports they utilized to overcome their challenges. Our interview guide was designed to elicit familial experiences during the pre- and post-diagnosis periods. The themes and sub-themes were identified through qualitative descriptive textual analysis of audio-recorded transcripts. Major themes identified include ambiguity of illness, changing family and spousal dynamics, and navigating the healthcare system. Sub-themes revolved around disease effects, psychological stressors, health systems, support, and facing the disease. Healthcare professionals have an opportunity to minimize the impact of negative emotional outcomes by assisting families as they navigate the experience of having a child with an IEM. Our findings can be used to develop and continue a more well-rounded, family-oriented framework for IEM management
Magnetorheological brushes â Scarcely explored class of magnetic material
Magnetic materials such as magnetorheological (MR) fluids, and magnetorheological elastomers exhibit a broad change in their material properties, for example, viscosity and storage modulus in the presence of a magnetic field. Studies related to such MR fluid and elastomer materials are extensively available. The MR brush, meanwhile, is less frequently explored and understood. An MR brush is defined by the brush-like structures formed from chains of magnetic particles embedded within a carrier matrix, typically fluids or elastomers. In this study, we explore magnetorheological fluid (MRF) brush and magnetorheological elastomer (MRE) brush and investigate their magneto-mechanical properties. The investigation measured the stiffness and the MR response, defined as the change in properties in the presence of a magnetic field for MRF and MRE brushes. Further dependence of the magnetic effect on material and preparation parameters, mainly concentration of magnetic particles and curing flux density (for MRE brush) were investigated. The responsiveness of the brushes is compared using the Magnetorheological response index, as a proposed metric in this study. The results indicate that the MRE brush possess a greater absolute stiffness, but a lower MR response than that of the MRF brush. Both MRF and MRE brushes show an increase in the MR response with an increased concentration of magnetic fillers. MRE brush further demonstrate an enhanced MR response, which could be highly comparable to MRF brush coinciding with an increase in the magnetic flux density during the curing process. The fundamental investigation of both solid and fluid MR brushes in this study opens a new avenue in the area of magnetic materials. This new class of magnetically controllable materials could potentially be employed in applications where soft and tuneable bristle-like structures are desired
Dose-Intensified Stereotactic Ablative Radiation for Localized Prostate Cancer
Purpose: Stereotactic ablative radiation (SAbR) has been increasingly used in prostate cancer (PCa) given its convenience and cost efficacy. Optimal doses remain poorly defined with limited prospective comparative trials and long-term safety/efficacy data at higher dose levels. We analyzed toxicity and outcomes for SAbR in men with localized PCa at escalated 45 Gy in 5 fractions.
Methods and Materials: This study retrospectively analyzed men from 2015 to 2019 with PCa who received linear-accelerator-based SAbR to 45 Gy in 5 fractions, along with perirectal hydrogel spacer, fiducial placement, and MRI-based planning. Disease control outcomes were calculated from end of treatment. Minimally important difference (MID) assessing patient-reported quality of life was defined as greater than a one-half standard deviation increase in American Urological Association (AUA) symptom score after SAbR.
Results: Two-hundred and forty-nine (249) low-, intermediate-, and high-risk PCa patients with median follow-up of 14.9 months for clinical toxicity were included. Acute urinary grade II toxicity occurred in 20.4% of patients. Acute grade II GI toxicity occurred in 7.3% of patients. For follow-up \u3e 2 years (n = 69), late GU and GI grade â„III toxicity occurred in 5.8% and 1.5% of patients, respectively. MID was evident in 31.8%, 23.4%, 35.8%, 37.0%, 33.3%, and 26.7% of patients at 3, 6, 12, 24, 36, and 48 months, respectively. The median follow-up for biochemical recurrence was 22.6 months with biochemical failure-free survival of 100% at 1 year (n = 226) and 98.7% for years 2 (n = 113) and 3 (n = 54).
Conclusions: SAbR for PCa at 45 Gy in 5 fractions shows an encouraging safety profile. Prospective studies with longer follow-up are warranted to establish this dose regimen as standard of care for PCa
Mechanical compartmentalization of the intestinal organoid enables crypt folding and collective cell migration
Intestinal organoids capture essential features of the intestinal epithelium such as crypt folding, cellular compartmentalization and collective movements. Each of these processes and their coordination require patterned forces that are at present unknown. Here we map three-dimensional cellular forces in mouse intestinal organoids grown on soft hydrogels. We show that these organoids exhibit a non-monotonic stress distribution that defines mechanical and functional compartments. The stem cell compartment pushes the extracellular matrix and folds through apical constriction, whereas the transit amplifying zone pulls the extracellular matrix and elongates through basal constriction. The size of the stem cell compartment depends on the extracellular-matrix stiffness and endogenous cellular forces. Computational modelling reveals that crypt shape and force distribution rely on cell surface tensions following cortical actomyosin density. Finally, cells are pulled out of the crypt along a gradient of increasing tension. Our study unveils how patterned forces enable compartmentalization, folding and collective migration in the intestinal epithelium
Bi-allelic variants in OGDHL cause a neurodevelopmental spectrum disease featuring epilepsy, hearing loss, visual impairment, and ataxia
The 2-oxoglutarate dehydrogenase-like (OGDHL) protein is a rate-limiting enzyme in the Krebs cycle that plays a pivotal role in mitochondrial metabolism. OGDHL expression is restricted mainly to the brain in humans. Here, we report nine individuals from eight unrelated families carrying bi-allelic variants in OGDHL with a range of neurological and neurodevelopmental phenotypes including epilepsy, hearing loss, visual impairment, gait ataxia, microcephaly, and hypoplastic corpus callosum. The variants include three homozygous missense variants (p.Pro852Ala, p.Arg244Trp, and p.Arg299Gly), three compound heterozygous single-nucleotide variants (p.Arg673Gln/p.Val488Val, p.Phe734Ser/p.Ala327Val, and p.Trp220Cys/p.Asp491Val), one homozygous frameshift variant (p.Cys553Leufsâ16), and one homozygous stop-gain variant (p.Arg440Ter). To support the pathogenicity of the variants, we developed a novel CRISPR-Cas9-mediated tissue-specific knockout with cDNA rescue system for dOgdh, the Drosophila ortholog of human OGDHL. Pan-neuronal knockout of dOgdh led to developmental lethality as well as defects in Krebs cycle metabolism, which was fully rescued by expression of wild-type dOgdh. Studies using the Drosophila system indicate that p.Arg673Gln, p.Phe734Ser, and p.Arg299Gly are severe loss-of-function alleles, leading to developmental lethality, whereas p.Pro852Ala, p.Ala327Val, p.Trp220Cys, p.Asp491Val, and p.Arg244Trp are hypomorphic alleles, causing behavioral defects. Transcript analysis from fibroblasts obtained from the individual carrying the synonymous variant (c.1464T>C [p.Val488Val]) in family 2 showed that the synonymous variant affects splicing of exon 11 in OGDHL. Human neuronal cells with OGDHL knockout exhibited defects in mitochondrial respiration, indicating the essential role of OGDHL in mitochondrial metabolism in humans. Together, our data establish that the bi-allelic variants in OGDHL are pathogenic, leading to a Mendelian neurodevelopmental disease in humans
Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.
BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence.
METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs.
RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate).
CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416
Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.
BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence.
METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs.
RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate).
CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416
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