229 results on '"Rajaram N"'
Search Results
52. Community Action for Social Justice: Grassroots Organizations in India Shashi Ranjan Pandey
- Author
-
Rajaram, N.
- Published
- 1991
53. Kinematic Analysis of Constant-Breadth Cam-Follower Mechanisms
- Author
-
Dhande, S. G. and Rajaram, N.
- Abstract
An analytical approach to the kinematic analysis of certain types of constant-breadth cam-follower mechanisms has been presented in this paper. The objective of the kinematic analysis is to provide closed-form parametric equations for the displacement, the velocity, and the acceleration of the follower driven by a constant-breadth cam profile rotating at a uniform angular velocity. The follower surface is considered to be a flat-face and the follower motion may either be translatory or oscillatory, or translatory as well as oscillatory. The proposed approach is general in nature and can be used for the kinematic analysis of any profile-closed higher-pair mechanism. Two different cam profiles of constant-breadth, termed as Type I and Type II, have been considered. Numerical examples have been worked out and results of the computational work have been discussed.
- Published
- 1984
- Full Text
- View/download PDF
54. A Study of Concentrated Solutions of Mixed Electrolytes. Ultrasonic Velocities and Viscosities of Mixtures of Aqueous Solutions of Potassium and Sodium Chlorides at High Concentrations
- Author
-
Kuppusami, J, Lakshmanan, A S, Lakshminarayanan, R, Rajaram, N, and Suryanarayana, C V
- Abstract
The electrical conductance of mixtures of aqueous solutions of potassium and sodium chlorides has been studied by previous workers. However, no valid explanation has been given for the conductance behaviour of the mixtures.We have reported herein the results of our ultrasonic of the viscometric studies of mixtures. Even now the hydration numbers and the viscosity variation are inadequate to explain the conductance behaviour of the mixtures. We have observed that all the mixtures follow the exponential relation, η=AeBμ, where Aand Bare constants; η the viscosity of the mixture, and μ, the ionic stregth.
- Published
- 1965
- Full Text
- View/download PDF
55. Design and Analysis of a Wind Turbine Blade with Dimples to Enhance the Efficiency through CFD with ANSYS R16.0
- Author
-
Rajaram Narayanan M., Nallusamy S., and Ragesh Sathiyan M.
- Subjects
Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In the global scenario, wind turbines and their aerodynamics are always subjected to constant research for increasing their efficiency which converts the abundant wind energy into usable electrical energy. In this research, an attempt is made to increase the efficiency through the changes in surface topology of wind turbines through computational fluid dynamics. Dimples on the other hand are very efficient in reducing air drag as is it evident from the reduction of drag and increase in lift in golf balls. The predominant factors influencing the efficiency of the wind turbines are lift and drag which are to be maximized and minimized respectively. In this research, surface of turbine blades are integrated with dimples of various sizes and arrangements and are analyzed using computational fluid dynamics to obtain an optimum combination. The analysis result shows that there is an increase in power with about 15% increase in efficiency. Hence, integration of dimples on the surface of wind turbine blades has helped in increasing the overall efficiency of the wind turbine.
- Published
- 2018
- Full Text
- View/download PDF
56. Patient-Reported Outcome Coordinator Did Not Improve Quality of Life Assessment Response Rates: A Report from the Children's Oncology Group.
- Author
-
Donna Johnston, Robert Gerbing, Todd Alonzo, Richard Aplenc, Rajaram Nagarajan, Fiona Schulte, Patricia Cullen, and Lillian Sung
- Subjects
Medicine ,Science - Abstract
Health related quality of life (HRQL) assessments during therapy for pediatric cancer provide valuable information to better understand the patient experience. Our objective was to determine the impact of a patient-reported outcome (PRO) coordinator on HRQL questionnaire completion rates during a pediatric acute myeloid leukemia (AML) trial.AAML1031 is a multicenter Children's Oncology Group therapeutic trial for de novo AML with a secondary aim to assess HRQL of children and adolescents treated with chemotherapy and hematopoietic stem cell transplantation (HSCT). Parents/guardians are the primary respondents and four questionnaires are administered at eight time points. The questionnaires are the PedsQL 4.0 Generic Core Scales, PedsQL 3.0 Acute Cancer Module, PedsQL Multidimensional Fatigue Scale, and the Pediatric Inventory for Parents. To improve response rates, a central PRO coordinator was instituted and reminded sites about upcoming and delinquent questionnaires. The proportion of HRQL questionnaires completed were compared prior to, and following institution of the PRO coordinator. This analysis evaluated the first five assessment time points.There were231 families who consented to participate in the HRQL aim. Overall response rates for all questionnaires were 73-83%. At time point 1, within 14 days of chemotherapy initiation, post-PRO coordinator completion rates were significantly higher for three of four questionnaires. However, the effect was not sustained and at time point 4, one month following last chemotherapy or HSCT, completion rates were significantly lower post-PRO coordinator for all four questionnaires.Addition of a central PRO coordinator did not result in sustained improvement in HRQL questionnaire completion rates. Efforts to improve response rates must consider other strategies.
- Published
- 2015
- Full Text
- View/download PDF
57. Kinematic Analysis of Constant-Breadth Cam-Follower Mechanisms
- Author
-
Dhande, S. G., primary and Rajaram, N., additional
- Published
- 1984
- Full Text
- View/download PDF
58. Book Reviews and Notices
- Author
-
Rajaram, N., primary
- Published
- 1989
- Full Text
- View/download PDF
59. Chemical Analysts and Nutritional Evaluation of Certain Under-Exploited Vigna Spp.
- Author
-
Rajaram, N., primary and Janardhanan, K., additional
- Published
- 1989
- Full Text
- View/download PDF
60. Reasons for non-completion of health related quality of life evaluations in pediatric acute myeloid leukemia: a report from the Children's Oncology Group.
- Author
-
Donna L Johnston, Rajaram Nagarajan, Mae Caparas, Fiona Schulte, Patricia Cullen, Richard Aplenc, and Lillian Sung
- Subjects
Medicine ,Science - Abstract
BackgroundHealth related quality of life (HRQL) assessments during therapy for pediatric cancer are important. The objective of this study was to describe reasons for failure to provide HRQL assessments during a pediatric acute myeloid leukemia (AML) clinical trial.MethodsWe focused on HRQL assessments embedded in a multicenter pediatric AML clinical trial. The PedsQL 4.0 Generic Core Scales, PedsQL 3.0 Acute Cancer Module, PedsQL Multidimensional Fatigue Scale, and Pediatric Inventory for Parents were obtained from parent/guardian respondents at a maximum of six time points. Children provided self-report optionally. A central study coordinator contacted sites with delinquent HRQL data. Reasons for failure to submit the HRQL assessments were evaluated by three pediatric oncologists and themes were generated using thematic analysis.ResultsThere were 906 completed and 1091 potential assessments included in this analysis (83%). The median age of included children was 12.9 years (range 2.0 to 18.9). The five themes for non-completion were: patient too ill; passive or active refusal by respondent; developmental delay; logistical challenges; and poor knowledge of study processes from both the respondent and institutional perspective.ConclusionsWe identified reasons for non-completion of HRQL assessments during active therapy. This information will facilitate recommendations to improve study processes and future HRQL study designs to maximize response rates.
- Published
- 2013
- Full Text
- View/download PDF
61. Erratum to “In Vivo Detection of Gold Nanoshells in Tumors Using Diffuse Optical Spectroscopy”.
- Author
-
Zaman, R. T., Diagaradjane, P., Wang, J. C., Schwartz, J., Rajaram, N., Gill-Sharp, K. L., Cho, S. H., Rylander, III, H. G., Payne, J. D., Krishnan, S., and Tunnell, J. W.
- Published
- 2008
- Full Text
- View/download PDF
62. Simple method for finding the ratio of surface tension to viscosity of a liquid.
- Author
-
Sreekantath, G. M., Rajaram, N., and Ponnappan, C. K.
- Published
- 1959
- Full Text
- View/download PDF
63. Changing Classes, Stratification and Mobility in Post-Industrial Societies (Book).
- Author
-
Rajaram, N.
- Abstract
Reviews the book "Changing Classes, Stratification and Mobility in Post-Industrial Societies," edited by Gosta Esping-Andersen.
- Published
- 1995
64. Community Action for Social Justice (Book).
- Author
-
Rajaram, N.
- Abstract
Reviews the book "Community Action for Social Justice: Grassroots Organizations in India," by Shashi Ranjan Pandey.
- Published
- 1991
65. A strategy for rural development: Dairy cooperatives in India (Book).
- Author
-
Rajaram, N.
- Subjects
RURAL development ,NONFICTION - Abstract
Reviews the book "A Strategy for Rural Development: Dairy Cooperatives in India," by R.C. Mascarenhas.
- Published
- 1989
- Full Text
- View/download PDF
66. Social Structure and Change (Book).
- Author
-
Rajaram, N.
- Abstract
Reviews the book "Social Structure and Change, vol. 3, Complex Organisations and Urban Communities," by A. M. Shah, B. S. Baviskar and E. A. Ramaswamy.
- Published
- 1998
67. LETTERS.
- Author
-
Ananth, S. Vijat, Ceyon, Ravichandran, Kandasamy, Anbu, Marciano, Katie, Rimal, Naresh, Lackey, Derwin, Shankar, P., Rajaram, N. S., Shanmugavadivel, Shan A., and Nambiar, Damodaran
- Subjects
- *
LETTERS to the editor , *REGENERATION (Theology) , *YOGA , *HINDUISM , *RELIGIONS , *RELIGIOUS behaviors - Abstract
Several letters to the editor are presented in response to the articles "Conversion in Malaysia," by Sivam Mane published in the July to September 2006 issue "Yoga Renamed Is Still Hindu," in the January to March 2006 issue, and "Assessing the Aryan Myth," by Rajiv Malhotra in the April to June 2006 issue.
- Published
- 2006
68. An unilateral double fenestration of the right external jugular vein: a rare variant.
- Author
-
Dhivyaashree R, Rajaram N, Banu J, Verma S, and Suma HY
- Subjects
- Humans, Male, Middle Aged, Dissection, Jugular Veins abnormalities, Jugular Veins anatomy & histology, Anatomic Variation, Cadaver
- Abstract
Objectives: This report presents a rare anatomical variation, double fenestration of the External jugular vein on the right side., Materials and Methods: During the routine dissection of a male cadaver aged 60 years, we observed a unilateral large double fenestration of the External jugular vein on the right side., Results: After its formation from the posterior division of the retromandibular and posterior auricular veins, External jugular vein descended in the posterior triangle of neck. Here, it divided into medial, intermediate, and lateral veins that united again before draining into the subclavian vein. Lateral vein was the largest (7.2 cm) and intermediate and medial veins were measuring 6.4 cm each. Two large fenestrations, measuring 5.8 cm each, arranged like a "double bubble" were seen in the External jugular vein extending from fourth to sixth cervical (C4 to C6) vertebrae. The medial branch of supraclavicular nerve was seen passing superficial to the distal part of External jugular vein. On the left side, the course of External jugular vein showed a standard pattern., Conclusion: Surgeons must be acquainted with the varied anatomy of the superficial neck veins to prevent major bleeding during operative procedures, including carotid endarterectomy, flap operations, & central venous catheterisation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
69. Investigating In Vivo Tumor Biomolecular Changes Following Radiation Therapy Using Raman Spectroscopy.
- Author
-
Karunakaran V, Dadgar S, Paidi SK, Mordi AF, Lowe WA, Mim UM, Ivers JD, Rodriguez Troncoso JI, McPeake JA, Fernandes A, Tripathi SD, Barman I, and Rajaram N
- Abstract
Treatment resistance is a major bottleneck in the success of cancer therapy. Early identification of the treatment response or lack thereof in patients can enable an earlier switch to alternative treatment strategies that can enhance response rates. Here, Raman spectroscopy was applied to monitor early tumor biomolecular changes in sensitive (UM-SCC-22B) and resistant (UM-SCC-47) head and neck tumor xenografts for the first time in in vivo murine tumor models in response to radiation therapy. We used a validated multivariate curve resolution-alternating least-squares (MCR-ALS) model to resolve complex multicomponent Raman spectra into individual pure spectra and their respective contributions. We observed a significant radiation-induced increase in the contributions of lipid-like species ( p = 0.0291) in the radiation-sensitive UM-SCC-22B tumors at 48 h following radiation compared to the nonradiated baseline (prior to commencing treatment). We also observed an increase in the contribution of collagen-like species in the radiation-resistant UM-SCC-47 tumors at 24 h following radiation compared to the nonradiated baseline ( p = 0.0125). In addition to the in vivo analysis, we performed ex vivo confocal Raman microscopic imaging of frozen sections derived from the same tumors. A comparison of all control and treated tumors revealed similar trends in the contributions of lipid-like and collagen-like species in both in vivo and ex vivo measurements; however, when evaluated as a function of time, longitudinal trends in the scores of collagen-like and lipid-like components were not consistent between the two data sets, likely due to sample numbers and differences in sampling depth at which information is obtained. Nevertheless, this study demonstrates the potential of fiber-based Raman spectroscopy for identifying early tumor microenvironmental changes in response to clinical doses of radiation therapy., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)
- Published
- 2024
- Full Text
- View/download PDF
70. Allele-specific DNA demethylation editing leads to stable upregulation of allele-specific gene expression.
- Author
-
Rajaram N, Benzler K, Bashtrykov P, and Jeltsch A
- Abstract
Epigenome editing is an emerging technology that allows to rewrite epigenome states and reprogram gene expression. Here, we have developed allele-specific DNA demethylation editing at gene promoters containing an SNP by sgRNA/dCas9 mediated recuitment of TET1. Maximal DNA demethylation (up to 90%) was observed 6 days after transient transfection of the epigenome editors and it was almost stable for 15 days. After allele-specific targeting, DNA demethylation was up to 15-fold more efficient at the targeted allele. Our data show that locus-specific and allele-specific DNA demethylation can trigger the expression of previously silenced genes. Allele-specific DNA demethylation shifted allelic expression ratios about 4-fold. Allele-specific DNA demethylation could be used to correct aberrant imprinting in patients suffering from imprinting disorders and to study the roles of individual alleles of a gene in a given cellular context., Competing Interests: The authors declare that they have no competing interests., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
71. Noncontact Diffuse Reflectance Spectroscopy of Synovial Fluid Samples for Rapid Identification of Infections.
- Author
-
Drewke EE, Brand RL, Geels CG, Jensen HK, Wong K, Sanders JD, and Rajaram N
- Abstract
Severe joint infections, such as septic arthritis, require rapid diagnostic testing of the synovial fluid aspirated from joints level so that a surgical team can be assembled quickly. We present a diffuse reflectance spectroscopy (DRS) system for noncontact determination of infection. Using a light-tight syringe holder and fiber optic probe, diffusely reflected light from 475 to 655 nm was acquired from 18 patient samples through the wall of a syringe in a noncontact and sterile manner. We determined the reflectance ratios at two different wavelengths-R
490 /R600 and R580 /R600 and found statistically significant differences (p < 0.05) in both ratios between the infected and noninfected groups. Critically, the R490 /R600 and R580 /R600 ratios were significantly correlated with clinical biomarkers-the white blood cell (WBC) and red blood cell (RBC) counts, respectively. This study demonstrates the potential of DRS as a rapid diagnostic tool for joint infections., (© 2024 The Author(s). Journal of Biophotonics published by Wiley‐VCH GmbH.)- Published
- 2024
- Full Text
- View/download PDF
72. Racial and skin color mediated disparities in pulse oximetry in infants and young children.
- Author
-
Sharma M, Brown AW, Powell NM, Rajaram N, Tong L, Mourani PM, and Schootman M
- Subjects
- Humans, Infant, Newborn, Infant, Healthcare Disparities, Child, Preschool, Hypoxia diagnosis, Racial Groups, Oxygen Saturation physiology, Oximetry, Skin Pigmentation
- Abstract
Race-based and skin pigmentation-related inaccuracies in pulse oximetry have recently been highlighted in several large electronic health record-based retrospective cohort studies across diverse patient populations and healthcare settings. Overestimation of oxygen saturation by pulse oximeters, particularly in hypoxic states, is disparately higher in Black compared to other racial groups. Compared to adult literature, pediatric studies are relatively few and mostly reliant on birth certificates or maternal race-based classification of comparison groups. Neonates, infants, and young children are particularly susceptible to the adverse life-long consequences of hypoxia and hyperoxia. Successful neonatal resuscitation, precise monitoring of preterm and term neonates with predominantly lung pathology, screening for congenital heart defects, and critical decisions on home oxygen, ventilator support and medication therapies, are only a few examples of situations that are highly reliant on the accuracy of pulse oximetry. Undetected hypoxia, especially if systematically different in certain racial groups may delay appropriate therapies and may further perpetuate health care disparities. The role of biological factors that may differ between racial groups, particularly skin pigmentation that may contribute to biased pulse oximeter readings needs further evaluation. Developmental and maturational changes in skin physiology and pigmentation, and its interaction with the operating principles of pulse oximetry need further study. Importantly, clinicians should recognize the limitations of pulse oximetry and use additional objective measures of oxygenation (like co-oximetry measured arterial oxygen saturation) where hypoxia is a concern., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
73. Presentation of Breast Cancer and Impact of Patient Navigation on Timeliness of Diagnosis and Treatment and on Adherence to Treatment Recommendations in a Multicenter Network in Malaysia.
- Author
-
Jaganathan M, Ang BH, Ali A, Sharif SZ, Mohamad M, Mohd Khairy A, Muniandy K, Zainal H, Sabtu F, Sapiee N, Zainal NH, Zaipudin NFH, Muniandi M, Ghazali AF, Roimin FO, Chong CCL, Rajaram N, Jaafar N, Julaihi R, Rahim N, Zakaria NA, Menon I, Tajudeen NA, Ho KY, Md Yusof S, Abdul Wahab MY, Ab Hadi IS, and Teo SH
- Subjects
- Humans, Female, Malaysia, Mammography, Breast pathology, Breast Neoplasms diagnostic imaging, Breast Neoplasms therapy, Patient Navigation methods
- Abstract
Purpose: Breast cancer deaths disproportionately affect women living in low- and middle-income countries (LMICs). Patient navigation has emerged as a cost-effective and impactful approach to enable women with symptoms or suspicious mammogram findings to access timely diagnosis and patients with breast cancer to access timely and appropriate multimodality treatment. However, few studies have systematically evaluated the impact of patient navigation on timeliness of diagnosis and treatment in LMICs., Methods: We established a nurse- and community-navigator-led navigation program in breast clinics of four public hospitals located in Peninsular and East Malaysia and evaluated the impact of navigation on timeliness of diagnosis and treatment., Results: Patients with breast cancer treated at public hospitals reported facing barriers to accessing care, including having a poor recognition of breast cancer symptoms and low awareness of screening methods, and facing financial and logistics challenges. Compared with patients diagnosed in the previous year, patients receiving navigation experienced timely ultrasound (84.0% v 65.0%; P < .001), biopsy (84.0% v 78.0%; P = .012), communication of news (63.0% v 40.0%; P < .001), surgery (46% v 36%; P = .008), and neoadjuvant therapy (59% v 42%, P = .030). Treatment adherence improved significantly (98.0% v 87.0%, P < .001), and this was consistent across the network of four breast clinics., Conclusion: Patient navigation improves access to timely diagnosis and treatment for women presenting at secondary and tertiary hospitals in Malaysia.
- Published
- 2024
- Full Text
- View/download PDF
74. Acquired Radiation Resistance Induces Thiol-dependent Cisplatin Cross-resistance.
- Author
-
Jenkins SV, Shah S, Jamshidi-Parsian A, Mortazavi A, Kristian H, Boysen G, Vang KB, Griffin RJ, Rajaram N, and Dings RPM
- Subjects
- Humans, Animals, Mice, Cisplatin pharmacology, Cisplatin therapeutic use, Carboplatin, Buthionine Sulfoximine pharmacology, Buthionine Sulfoximine therapeutic use, Drug Resistance, Neoplasm genetics, Cell Line, Tumor, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Carcinoma, Non-Small-Cell Lung genetics, Carcinoma, Non-Small-Cell Lung radiotherapy, Lung Neoplasms genetics, Lung Neoplasms radiotherapy
- Abstract
Resistance to radiation remains a significant clinical challenge in non-small cell lung carcinoma (NSCLC). It is therefore important to identify the underlying molecular and cellular features that drive acquired resistance. We generated genetically matched NSCLC cell lines to investigate characteristics of acquired resistance. Murine Lewis lung carcinoma (LLC) and human A549 cells acquired an approximate 1.5-2.5-fold increase in radiation resistance as compared to their parental match, which each had unique intrinsic radio-sensitivities. The radiation resistance (RR) was reflected in higher levels of DNA damage and repair marker γH2AX and reduced apoptosis induction after radiation. Morphologically, we found that radiation resistance A549 (A549-RR) cells exhibited a greater nucleus-to-cytosol (N/C) ratio as compared to its parental counterpart. Since the N/C ratio is linked to the differentiation state, we next investigated the epithelial-to-mesenchymal transition (EMT) phenotype and cellular plasticity. We found that A549 cells had a greater radiation-induced plasticity, as measured by E-cadherin, vimentin and double-positive (DP) modulation, as compared to LLC. Additionally, migration was suppressed in A549-RR cells, as compared to A549 cells. Subsequently, we confirmed in vivo that the LLC-RR and A549-RR cells are also more resistance to radiation than their isogenic-matched counterpart. Moreover, we found that the acquired radiation resistance also induced resistance to cisplatin, but not carboplatin or oxaliplatin. This cross-resistance was attributed to induced elevation of thiol levels. Gamma-glutamylcysteine synthetase inhibitor buthionine sulfoximine (BSO) sensitized the resistant cells to cisplatin by decreasing the amount of thiols to levels prior to obtaining acquired radiation resistance. By generating radiation-resistance genetically matched NSCLC we were able to identify and overcome cisplatin cross-resistance. This is an important finding arguing for combinatorial treatment regimens including glutathione pathway disruptors in patients with the potential of improving clinical outcomes in the future., (© 2024 by Radiation Research Society.)
- Published
- 2024
- Full Text
- View/download PDF
75. Locus-Specific and Stable DNA Demethylation at the H19 / IGF2 ICR1 by Epigenome Editing Using a dCas9-SunTag System and the Catalytic Domain of TET1.
- Author
-
Albrecht C, Rajaram N, Broche J, Bashtrykov P, and Jeltsch A
- Subjects
- Humans, Catalytic Domain, Epigenome, HEK293 Cells, Alleles, Mixed Function Oxygenases genetics, Proto-Oncogene Proteins, Insulin-Like Growth Factor II genetics, DNA Demethylation, Imprinting Disorders
- Abstract
DNA methylation is critically involved in the regulation of chromatin states and cell-type-specific gene expression. The exclusive expression of imprinted genes from either the maternal or the paternal allele is regulated by allele-specific DNA methylation at imprinting control regions (ICRs). Aberrant DNA hyper- or hypomethylation at the ICR1 of the H19/IGF2 imprinting locus is characteristic for the imprinting disorders Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS), respectively. In this paper, we performed epigenome editing to induce targeted DNA demethylation at ICR1 in HEK293 cells using dCas9-SunTag and the catalytic domain of TET1. 5-methylcytosine (5mC) levels at the target locus were reduced up to 90% and, 27 days after transient transfection, >60% demethylation was still observed. Consistent with the stable demethylation of CTCF-binding sites within the ICR1, the occupancy of the DNA methylation-sensitive insulator CTCF protein increased by >2-fold throughout the 27 days. Additionally, the H19 expression was increased by 2-fold stably, while IGF2 was repressed though only transiently. Our data illustrate the ability of epigenome editing to implement long-term changes in DNA methylation at imprinting control regions after a single transient treatment, potentially paving the way for therapeutic epigenome editing approaches in the treatment of imprinting disorders.
- Published
- 2024
- Full Text
- View/download PDF
76. Protocol for Allele-Specific Epigenome Editing Using CRISPR/dCas9.
- Author
-
Rajaram N, Bashtrykov P, and Jeltsch A
- Subjects
- Humans, HEK293 Cells, RNA, Guide, CRISPR-Cas Systems genetics, Epigenomics methods, Epigenesis, Genetic, Gene Editing methods, CRISPR-Cas Systems, Alleles, DNA Methylation, Epigenome
- Abstract
The discovery and adaptation of CRISPR/Cas systema for epigenome editing has allowed for a straightforward design of targeting modules that can direct epigenome editors to virtually any genomic site. This advancement in DNA-targeting technology brings allele-specific epigenome editing into reach, a "super-specific" variation of epigenome editing whose goal is an alteration of chromatin marks at only one selected allele of the genomic target locus. This technology could be useful for the treatment of diseases caused by a mutant allele with a dominant effect, because allele-specific epigenome editing allows the specific silencing of the mutated allele leaving the healthy counterpart expressed. Moreover, it may allow the direct correction of aberrant imprints in imprinting disorders where editing of DNA methylation is required exclusively in a single allele. Here, we describe a basic protocol for the design and application of allele-specific epigenome editing systems using allele-specific DNA methylation at the NARF gene in HEK293 cells as an example. An sgRNA/dCas9 unit is used for allele-specific binding to the target locus containing a SNP in the seed region of the sgRNA or the PAM region. The dCas9 protein is connected to a SunTag allowing to recruit up to 10 DNMT3A/3L units fused to a single-chain Fv fragment, which specifically binds to the SunTag peptide sequence. The plasmids expressing dCas9-10x SunTag, scFv-DNMT3A/3L, and sgRNA, each of them co-expressing a fluorophore, are introduced into cells by co-transfection. Cells containing all three plasmids are enriched by FACS, cultivated, and later the genomic DNA and RNA can be retrieved for DNA methylation and gene expression analysis., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
77. Human navicular bone: a morphometric and morphological evaluation.
- Author
-
Rajaram N, Srinivasan S, and Verma S
- Subjects
- Humans, Foot, Tendons anatomy & histology, Cadaver, Tarsal Bones anatomy & histology
- Abstract
Background: The composition of navicular joint complex is crucial to perform surgical interventions for multiple pathological foot aetiologies. The data on human navicular bone and its facets from Indian population remain scarce in literature., Aims and Objectives: To evaluate the morphometry and morphology of navicular bone., Methodology: A total of 77 (right: 40; left: 37) dried human navicular bones were used. The collected data were entered and analysed in SPSS software., Results: The anteroposterior diameter of navicular bone on right side was 15.19 mm (13.92, 16.77) and on left side was 15.87 mm (13.83, 17.27). The transverse diameter on right and left sides were 34.21 mm (31.74, 36.6) and 33.59 mm (30.23, 35.43), respectively. The vertical diameter measured on the right was 22.31 mm (21.19, 23.94) and on left 22.53 mm (20.8, 24.24). Morphometric evaluation showed no significant difference between right and left navicular bones. The commonest shape for posterior facet was quadrilateral, on the right (62.5%) and left (40.5%). The most common shape of anterior facet for medial cuneiform is quadrilateral, on the right (85%) and left (89.1%). For intermediate cuneiform, triangular facet was common on the right side (72.5%) and on the left (59.5%). The lateral cuneiform facet was bean shaped on right side (72.5%) and quadrilateral on the left side (32.5%). There was a significant difference in shape distribution between right and left (P < 0.05). The median length of the groove for tibialis posterior tendon was 18.01 mm and 16.19 mm on right and left side, respectively. Cuboid facet was observed in 28 (70%) and 26 (65.9%) navicular bones on right and left sides, respectively., Conclusion: There is no significant difference between right and left bones with regards to morphometric parameters. Morphological evaluation revealed significant difference in the distribution of shape between right and left bones., (© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)
- Published
- 2024
- Full Text
- View/download PDF
78. Targeting oncogenic TERT promoter variants by allele-specific epigenome editing.
- Author
-
Kouroukli AG, Rajaram N, Bashtrykov P, Kretzmer H, Siebert R, Jeltsch A, and Bens S
- Subjects
- Humans, Alleles, DNA Methylation, Epigenome, RNA, Guide, CRISPR-Cas Systems, Promoter Regions, Genetic, Nucleotides, Mutation, Lung Neoplasms, Telomerase genetics
- Abstract
Background: Activation of dominant oncogenes by small or structural genomic alterations is a common driver mechanism in many cancers. Silencing of such dominantly activated oncogenic alleles, thus, is a promising strategy to treat cancer. Recently, allele-specific epigenome editing (ASEE) has been described as a means to reduce transcription of genes in an allele-specific manner. In cancer, specificity to an oncogenic allele can be reached by either targeting directly a pathogenic single-nucleotide variant or a polymorphic single-nucleotide variant linked to the oncogenic allele. To investigate the potential of ASEE in cancer, we here explored this approach by targeting variants at the TERT promoter region. The TERT promoter region has been described as one of the most frequently mutated non-coding cancer drivers., Results: Sequencing of the TERT promoter in cancer cell lines showed 53% (41/77) to contain at least one heterozygous sequence variant allowing allele distinction. We chose the hepatoblastoma cell line Hep-G2 and the lung cancer cell line A-549 for this proof-of-principle study, as they contained two different kinds of variants, namely the activating mutation C228T in the TERT core promoter and the common SNP rs2853669 in the THOR region, respectively. These variants were targeted in an allele-specific manner using sgRNA-guided dCas9-DNMT3A-3L complexes. In both cell lines, we successfully introduced DNA methylation specifically to the on-target allele of the TERT promoter with limited background methylation on the off-target allele or an off-target locus (VEGFA), respectively. We observed a maximum CpG methylation gain of 39% and 76% on the target allele when targeting the activating mutation and the common SNP, respectively. The epigenome editing translated into reduced TERT RNA expression in Hep-G2., Conclusions: We applied an ASEE-mediated approach to silence TERT allele specifically. Our results show that the concept of dominant oncogene inactivation by allele-specific epigenome editing can be successfully translated into cancer models. This new strategy may have important advantages in comparison with existing therapeutic approaches, e.g., targeting telomerase, especially with regard to reducing adverse side effects., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
79. Evaluating differences in optical properties of indolent and aggressive murine breast tumors using quantitative diffuse reflectance spectroscopy.
- Author
-
Rodriguez Troncoso J, Marium Mim U, Ivers JD, Paidi SK, Harper MG, Nguyen KG, Ravindranathan S, Rebello L, Lee DE, Zaharoff DA, Barman I, and Rajaram N
- Abstract
We used diffuse reflectance spectroscopy to quantify tissue absorption and scattering-based parameters in similarly sized tumors derived from a panel of four isogenic murine breast cancer cell lines (4T1, 4T07, 168FARN, 67NR) that are each capable of accomplishing different steps of the invasion-metastasis cascade. We found lower tissue scattering, increased hemoglobin concentration, and lower vascular oxygenation in indolent 67NR tumors incapable of metastasis compared with aggressive 4T1 tumors capable of metastasis. Supervised learning statistical approaches were able to accurately differentiate between tumor groups and classify tumors according to their ability to accomplish each step of the invasion-metastasis cascade. We investigated whether the inhibition of metastasis-promoting genes in the highly metastatic 4T1 tumors resulted in measurable optical changes that made these tumors similar to the indolent 67NR tumors. These results demonstrate the potential of diffuse reflectance spectroscopy to noninvasively evaluate tumor biology and discriminate between indolent and aggressive tumors., Competing Interests: The authors declare no potential conflicts of interest., (© 2023 Optica Publishing Group.)
- Published
- 2023
- Full Text
- View/download PDF
80. Development of super-specific epigenome editing by targeted allele-specific DNA methylation.
- Author
-
Rajaram N, Kouroukli AG, Bens S, Bashtrykov P, and Jeltsch A
- Subjects
- Humans, Epigenesis, Genetic, Alleles, HEK293 Cells, Epigenome, CRISPR-Cas Systems, Gene Editing, DNA Methylation, RNA, Guide, CRISPR-Cas Systems
- Abstract
Background: Epigenome editing refers to the targeted reprogramming of genomic loci using an EpiEditor which may consist of an sgRNA/dCas9 complex that recruits DNMT3A/3L to the target locus. Methylation of the locus can lead to a modulation of gene expression. Allele-specific DNA methylation (ASM) refers to the targeted methylation delivery only to one allele of a locus. In the context of diseases caused by a dominant mutation, the selective DNA methylation of the mutant allele could be used to repress its expression but retain the functionality of the normal gene., Results: To set up allele-specific targeted DNA methylation, target regions were selected from hypomethylated CGIs bearing a heterozygous SNP in their promoters in the HEK293 cell line. We aimed at delivering maximum DNA methylation with highest allelic specificity in the targeted regions. Placing SNPs in the PAM or seed regions of the sgRNA, we designed 24 different sgRNAs targeting single alleles in 14 different gene loci. We achieved efficient ASM in multiple cases, such as ISG15, MSH6, GPD1L, MRPL52, PDE8A, NARF, DAP3, and GSPT1, which in best cases led to five to tenfold stronger average DNA methylation at the on-target allele and absolute differences in the DNA methylation gain at on- and off-target alleles of > 50%. In general, loci with the allele discriminatory SNP positioned in the PAM region showed higher success rate of ASM and better specificity. Highest DNA methylation was observed on day 3 after transfection followed by a gradual decline. In selected cases, ASM was stable up to 11 days in HEK293 cells and it led up to a 3.6-fold change in allelic expression ratios., Conclusions: We successfully delivered ASM at multiple genomic loci with high specificity, efficiency and stability. This form of super-specific epigenome editing could find applications in the treatment of diseases caused by dominant mutations, because it allows silencing of the mutant allele without repression of the expression of the normal allele thereby minimizing potential side-effects of the treatment., (© 2023. BioMed Central Ltd., part of Springer Nature.)
- Published
- 2023
- Full Text
- View/download PDF
81. Silicosis, asbestosis, and pulmonary fibrosis in Ontario, Canada from 1996 to 2019.
- Author
-
Zhang Y, Rajaram N, Lau A, Mehta K, Holness DL, Tarlo SM, and Arrandale VH
- Subjects
- Male, Humans, Aged, Ontario epidemiology, Silicon Dioxide analysis, Asbestosis epidemiology, Asbestosis complications, Pulmonary Fibrosis, Silicosis etiology, Occupational Exposure adverse effects, Occupational Exposure analysis
- Abstract
Background: Silicosis is a fibrotic lung disease caused by exposure to respirable crystalline silica. Historically, silicosis was common among miners and other professions in the 20th century, and in recent decades has re-emerged in coal mining and appeared in new workplaces, including the manufacture of distressed jeans and artificial stone countertops., Methods: Physician billing data for the province of Ontario between 1992 and 2019 were analyzed across six time-periods (1993-1995, 1996-2000, 2001-2005, 2006-2010, 2011-2015, and 2016-2019). The case definition was two or more billing records within 24 months with a silicosis diagnosis code (ICD-9 502, ICD-10 J62). Cases from 1993 to 1995 were excluded as prevalent cases. Crude incidence rates per 100,000 persons were calculated by time-period, age, sex, and region. Analyses were repeated in parallel for pulmonary fibrosis (PF) (ICD-9 515, ICD-10 J84) and asbestosis (ICD-9 501; ICD-10 J61)., Results: From 1996 to 2019, 444 cases of silicosis, 2719 cases of asbestosis and 59,228 cases of PF were identified. Silicosis rates decreased from 0.42 cases per 100,000 in 1996-2000 to 0.06 per 100,000 people in 2016-2019. A similar trend was observed for asbestosis (1.66 to 0.51 per 100,000 persons) but the incidence rate of PF increased from 11.6 to 33.9 per 100,000 persons. Incidence rates for all outcomes were higher among men and older adults., Conclusions: A decreasing incidence of silicosis was observed in this analysis. However, the incidence of PF increased, consistent with findings from other jurisdictions. While cases of silicosis have been recorded among artificial stone workers in Ontario these cases do not seem to have impacted the population rates thus far. Ongoing, periodic surveillance of occupational diseases is helpful for tracking population-level trends over time., (© 2023 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals LLC.)
- Published
- 2023
- Full Text
- View/download PDF
82. Perceptions, attitudes and beliefs towards soya among healthy Asian women participating in a soya randomised controlled trial.
- Author
-
Yap B, Rajaram N, Ho WK, Khor GL, and Teo SH
- Subjects
- Humans, Female, Malaysia, Surveys and Questionnaires, Middle Aged, Dietary Supplements, Health Knowledge, Attitudes, Practice, Diet, Soy Foods
- Abstract
The soya-breast cancer risk relationship remains controversial in Asia due to limited and inconsistent research findings and is exacerbated by difficulties in recruiting and retaining participants in intervention trials. Understanding public perceptions towards soya is important for designing effective intervention trials. Here, we administered a close-ended, quantitative survey to healthy, peri- and post-menopausal Asian women in the Malaysian Soy and Mammographic Density (MiSo) Study to assess perception towards soya and explore motivators and barriers that affect study adherence using the Capability, Opportunity, Motivation and Belief (COM-B) Model and Theoretical Domains Framework (TDF). Of 118 participants, the majority reported the belief that soya promotes good health (Supplement = 85⋅7 %, Diet = 90⋅0 %, Control = 87⋅9 %). Most participants reported obtaining information about soya from the internet (Supplement = 61⋅0 %, Diet = 55⋅3 %, Control = 35⋅9 %), while health professionals were least reported (Supplement = 9⋅8 %, Diet = 7⋅9 %, Control = 5⋅1 %). Stratified analyses by study completion and adherence status yielded comparable findings. By the end of the study, dietary arm participants reported a strong belief that soya has no impact on their health (Supplement = 7⋅1 % v. Diet = 20⋅0 % v. Control = 0⋅0 %, P = 0⋅012). Motivation and opportunity strongly facilitated soya consumption, while psychological capability was the most common barrier to consumption though less evident among dietary arm participants. While most Asian women have a positive perception towards soya, theory-based intervention trials are warranted to understand the perception-study adherence relationship and to accurately inform the public of the health effects of soya., (© Cancer Research Malaysia 2023.)
- Published
- 2023
- Full Text
- View/download PDF
83. Development of open-source software for free-hand 3D vascular ultrasound: Dialysis fistula application.
- Author
-
Weitzel WF, Rajaram N, Zheng Y, Funes-Lora MA, Hamilton J, Yessayan L, Krishnamurthy VN, Henke P, Osborne N, Bishop B, Shih AJ, and Thelen BJ
- Subjects
- Humans, Renal Dialysis, Ultrasonography, Doppler, Software, Vascular Patency, Arteriovenous Shunt, Surgical adverse effects, Fistula
- Abstract
Background: The arteriovenous fistula (AVF) is the preferred vascular access for End Stage Renal Disease, having superior patency and lower infection risks than prosthetic graft and catheter access. When AVF dysfunction or delayed maturation does occur, the gold standard for diagnosis is the fistula angiogram (a.k.a. fistulogram). 3D ultrasound is available for obstetrical and other specialized uses, but it is cost prohibitive and has a field of view that is too small to cover the region of interest for the dialysis fistula application. We sought to develop a point of care 3D solution using freehand 2D ultrasound data acquisition., Methods: We developed open-source software for 3D image reconstruction and projection of an angiogram-like image of the vascular access using a 2D freehand ultrasound scanner. We evaluated this software by comparing the ultrasound "sono-angiogram" images to fistulogram images in five subjects, using visual inspection and by applying the Percent of Exact Match (PEM) as a statistic test., Results: The sono-angiograms showed identifiable characteristics that matched the fistulogram results in all five subjects. The PEM ranged between 42.8% and 77.0%, with Doppler and grayscale ultrasound data, showing complementary advantages and disadvantages when used for sono-angiogram image construction. Motion from freehand ultrasound acquisition was a significant source of mismatch. 3D image generation is a potential advantage with ultrasound data., Conclusions: While further work is needed to improve the accuracy with free hand scanning, fistulogram-like "sono-angiograms" can be generated using point of care 2D ultrasound. Methods such as these may be able to assist in point-of-care diagnosis in the future. The software is open-source, and importantly, the ultrasound data used are non-proprietary and available from any standard ultrasound machine. The simplicity and accessibility of this approach warrant further study., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2023
- Full Text
- View/download PDF
84. The DNA methylation status of the TERT promoter differs between subtypes of mature B-cell lymphomas.
- Author
-
Kouroukli AG, Fischer A, Kretzmer H, Chteinberg E, Rajaram N, Glaser S, Kolarova J, Bashtrykov P, Mathas S, Drexler HG, Ohno H, Ammerpohl O, Jeltsch A, Siebert R, and Bens S
- Subjects
- Humans, DNA Methylation, CpG Islands, Lymphoma, B-Cell genetics, Telomerase genetics, Telomerase metabolism
- Published
- 2023
- Full Text
- View/download PDF
85. DNA methylation GrimAge acceleration in US military veterans with PTSD.
- Author
-
Katrinli S, King AP, Duval ER, Smith AK, Rajaram N, Liberzon I, and Rauch SAM
- Subjects
- Humans, Aging, DNA Methylation, Sertraline therapeutic use, Military Personnel, Stress Disorders, Post-Traumatic genetics, Stress Disorders, Post-Traumatic therapy, Veterans
- Abstract
Epigenetic alterations in DNA methylation might mediate gene expression effects of trauma underlying PTSD symptoms, or effects of PTSD on related health problems. PTSD is associated with all-cause morbidity and premature mortality, suggesting accelerated biological aging. We measured genome-wide DNA methylation (Illumina MethylationEPIC BeadChip) in whole blood in a treatment study for combat-related PTSD - "PROGrESS", a multisite RCT comparing sertraline plus enhanced medication management (SERT + EMM), prolonged exposure (PE) therapy plus placebo (PE + PLB), and the combination (SERT + PE). DNA methylation was measured in 140 US military veterans who served in Iraq and/or Afghanistan (112 current PTSD cases enrolled in a PTSD treatment study and 28 veterans without PTSD history controls), and also 59 non-trauma exposed controls at baseline posttreatment (24 weeks after baseline). Increased DNA methylation GrimAge acceleration (p = 8.8e-09) was observed in patients with PTSD compared to a pooled control group (trauma exposed and non-trauma exposed), suggesting a higher risk of premature mortality in those with PTSD. There was no difference in GrimAge acceleration between combat trauma and non-trauma exposed controls. No treatment-related changes in GrimAge acceleration were found in within-subject comparisons of PTSD patients pre- to post-treatment., (© 2023. The Author(s), under exclusive licence to American College of Neuropsychopharmacology.)
- Published
- 2023
- Full Text
- View/download PDF
86. Do diurnal salivary cortisol curves carry meaningful information about the regulatory biology of the HPA axis in healthy humans?
- Author
-
Abelson JL, Sánchez BN, Mayer SE, Briggs H, Liberzon I, and Rajaram N
- Subjects
- Humans, Pituitary-Adrenal System metabolism, Metyrapone, Circadian Rhythm physiology, Saliva metabolism, Dexamethasone metabolism, Biology, Hydrocortisone metabolism, Hypothalamo-Hypophyseal System metabolism
- Abstract
Salivary cortisol stress biomarkers have been extensively used in epidemiological work to document links between stress and ill health. There has been little effort to ground field friendly cortisol measures in the hypothalamic-pituitary-adrenal (HPA) axis regulatory biology that is likely relevant to delineating mechanistic pathways leading from stress exposure to detrimental health outcomes. Here, we utilized a healthy convenience sample (n = 140) to examine normal linkages between extensively collected salivary cortisol measures and available laboratory probes of HPA axis regulatory biology. Participants provided 9 saliva samples per day over 6 days within a month, while engaging in usual activities, and also participated in 5 regulatory tests (adrenocorticoptripin stimulation, dexamethasone/corticotropin-releasing-hormone stimulation, metyrapone, dexamethasone suppression, and Trier Social Stress Test). Logistical regression was used to test specific predictions linking cortisol curve components to regulatory variables and to explore widely for non-predicted associations. We found support for 2 of 3 original hypotheses, showing associations (1) between cortisol diurnal decline and feedback sensitivity as measured by dexamethasone suppression, and (2) between morning cortisol levels and adrenal sensitivity. We did not find links between central drive (metyrapone test) and end of day salivary levels. We confirmed an a priori expectation of limited linkage between regulatory biology and diurnal salivary cortisol measures, beyond those predicted. These data support an emerging focus on measures related to diurnal decline in epidemiological stress work. They raise questions about the biological meaning of other curve components, including morning cortisol levels, and perhaps CAR (Cortisol Awakening Response). If morning cortisol dynamics are linked to stress, more work on adrenal sensitivity in stress adaptation and stress-health links may be warranted., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
87. Barriers to help-seeking for Malaysian women with symptoms of breast cancer: a mixed-methods, two-step cluster analysis.
- Author
-
Rajaram N, Jaganathan M, Muniandy K, Rajoo Y, Zainal H, Rahim N, Tajudeen NA, Zainal NH, Mohd Khairy A, Abdul Wahab MY, and Teo SH
- Subjects
- Female, Humans, Asian People, Cluster Analysis, Emotions, Malaysia, Breast Neoplasms, Help-Seeking Behavior, Patient Acceptance of Health Care
- Abstract
Background: Improving help-seeking behaviour is a key component of down-staging breast cancer and improving survival, but the specific challenges faced by low-income women in an Asian setting remain poorly characterized. Here, we determined the extent of help-seeking delay among Malaysian breast cancer patients who presented at late stages and explored sub-groups of women who may face specific barriers., Methods: Time to help-seeking was assessed in 303 women diagnosed with advanced breast cancer between January 2015 and March 2020 at a suburban tertiary hospital in Malaysia. Two-step cluster analysis was conducted to identify subgroups of women who share similar characteristics and barriers. Barriers to help-seeking were identified from nurse interviews and were analyzed using behavioural frameworks., Results: The average time to help-seeking was 65 days (IQR = 250 days), and up to 44.5% of women delayed by at least 3 months. Three equal-sized clusters emerged with good separation by time to help-seeking (p < 0.001). The most reported barrier across clusters was poor knowledge about breast health or breast cancer symptoms (36.3%), regardless of help-seeking behaviour (p = 0.931). Unexpectedly, women with no delay (9 days average) and great delay (259 days average) were more similar to each other than to women with mild delays (58 days average), but, women who experienced great delay reported poor motivation due to fear and embarrassment (p = 0.066) and a lack of social support (p = 0.374) to seek help., Conclusions: Down-staging of breast cancer in Malaysia will require a multi-pronged approach aimed at modifying culturally specific social and emotional barriers, eliminating misinformation, and instilling motivation to seek help for breast health for the women most vulnerable to help-seeking delays., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
88. A Randomized Controlled Trial of Soy Isoflavone Intake on Mammographic Density among Malaysian Women.
- Author
-
Rajaram N, Yap B, Eriksson M, Mariapun S, Tan LM, Sa'at H, Ho ELM, Taib NAM, Khor GL, Yip CH, Ho WK, Hall P, and Teo SH
- Subjects
- Female, Humans, Breast Density, Breast diagnostic imaging, Mammography, Isoflavones pharmacology, Breast Neoplasms diagnostic imaging, Breast Neoplasms prevention & control
- Abstract
Soy intake is associated with lower breast cancer risk in observational studies concerning Asian women, however, no randomized controlled trials (RCT) have been conducted among Asian women living in Asia. This three-armed RCT assessed the effects of one-year soy isoflavone (ISF) intervention on mammographic density (MD) change among healthy peri- and postmenopausal Malaysian women. This study was registered at ClinicalTrials.gov (NCT03686098). Participants were randomized into the 100 mg/day ISF Supplement, 50 mg/day ISF Diet, or control arm, and assessed for change in absolute and relative dense area from digital mammograms conducted at enrolment and after 12 months, compared over time across study arms using Kruskal-Wallis tests. Out of 118 women enrolled, 91 women completed the intervention, while 27 women (23%) were lost in follow up. The ISF supplement arm participants observed a larger decline in dense area (−1.3 cm2), compared to the ISF diet (−0.5 cm2) and control arm (−0.8 cm2), though it was not statistically significant (p = 0.48). Notably, among women enrolled within 5 years of menopause; dense area declined by 6 cm2 in the ISF supplement arm, compared to <1.0 cm2 in the control arm (p = 0.13). This RCT demonstrates a possible causal association between soy ISF intake and MD, a biomarker of breast cancer risk, among Asian women around the time of menopause, but these findings require confirmation in a larger trial.
- Published
- 2023
- Full Text
- View/download PDF
89. Efficient Targeted DNA Methylation with dCas9-Coupled DNMT3A-DNMT3L Methyltransferase.
- Author
-
Bashtrykov P, Rajaram N, and Jeltsch A
- Subjects
- CRISPR-Cas Systems genetics, Chromatin, DNA metabolism, DNA (Cytosine-5-)-Methyltransferases genetics, DNA (Cytosine-5-)-Methyltransferases metabolism, DNA Modification Methylases genetics, Epigenesis, Genetic, Gene Editing, Methyltransferases metabolism, Transcription Factors metabolism, DNA Methylation, RNA, Guide, CRISPR-Cas Systems genetics, RNA, Guide, CRISPR-Cas Systems metabolism
- Abstract
Epigenome editing is a powerful approach for the establishment of a chromatin environment with desired properties at a selected genomic locus, which is used to influence the transcription of target genes and to study properties and functions of gene regulatory elements. Targeted DNA methylation is one of the most often used types of epigenome editing, which typically aims for gene silencing by methylation of gene promoters. Here, we describe the design principles of EpiEditors for targeted DNA methylation and provide step-by-step guidelines for the realization of this approach. We focus on the dCas9 protein as the state-of-the-art DNA targeting module fused to 10×SunTag as the most frequently used system for editing enhancement. Further, we discuss different flavors of DNA methyltransferase modules used for this purpose including the most specific variants developed recently. Finally, we explain the principles of gRNA selection, outline the setup of the cell culture experiments, and briefly introduce the available options for the downstream DNA methylation data analysis., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2023
- Full Text
- View/download PDF
90. Diffuse Reflectance Spectroscopy of Changes in Tumor Microenvironment in Response to Different Doses of Radiation.
- Author
-
Jules A, Means D, Troncoso JR, Fernandes A, Dadgar S, Siegel ER, and Rajaram N
- Subjects
- Animals, Humans, Mice, Hemoglobins, Spectrum Analysis, Tumor Microenvironment
- Abstract
Radiation therapy plays an important role in cancer treatment, as it is an established method used as part of the treatment plan for the majority of cancer patients. Real-time monitoring of the effects of radiation on the tumor microenvironment can contribute to the development of better treatment plans. In this study, we use diffuse reflectance spectroscopy, a non-invasive optical fiber-based technique, to determine the effects of different doses of radiation on the tumor microenvironment, as well as to determine the sensitivity of diffuse reflectance spectroscopy to low doses of radiation that are used in the treatment of certain cancers. We injected 4T1 cells into 50 Balb/c mice to generate tumor xenografts. When the tumors grew to 200 mm3, we distributed the mice into a control group or one of three radiation groups: 1, 2, or 4 Gy/fraction, and they underwent treatment for five consecutive days. We measured the tumor volume and collected diffuse reflectance spectra every day, with optical measurements being acquired both before and one h postirradiation on the five days of treatment. Based on the diffusely reflected light, we quantified vascular oxygenation, total hemoglobin content, and tissue scattering within these tumors. There was a significant increase in tumor vascular oxygenation, which was primarily due to an increase in oxygenated hemoglobin, in response to a 1 Gy/fraction of radiation, while there was a decrease in tissue scattering in response to all doses of radiation. Immunohistochemical analysis revealed that tumor cell proliferation and apoptosis were higher in irradiated groups compared to the control group. Our findings show that diffuse reflectance spectroscopy is sensitive to microenvironmental changes in tumors treated with doses of radiation as low as 1 Gy/fraction., (©2022 by Radiation Research Society. All rights of reproduction in any form reserved.)
- Published
- 2022
- Full Text
- View/download PDF
91. Sono-angiography for dialysis vascular access based on the freehand 2D ultrasound scanning.
- Author
-
Weitzel WF, Rajaram N, Krishnamurthy VN, Hamilton J, Thelen BJ, Zheng Y, Morgan T, Funes-Lora MA, Yessayan L, Bishop B, and Shih AJ
- Subjects
- Humans, Renal Dialysis, Ultrasonography methods, Angiography, Arteriovenous Shunt, Surgical adverse effects, Arteriovenous Shunt, Surgical methods, Kidney Failure, Chronic diagnosis, Kidney Failure, Chronic therapy
- Abstract
Introduction: Dialysis vascular access, preferably an autogenous arteriovenous fistula, remains an end stage renal disease (ESRD) patient's lifeline providing a means of connecting the patient to the dialysis machine. Once an access is created, the current gold standard of care for maintenance of vascular access is angiography and angioplasty to treat stenosis. While point of care 2D ultrasound has been used to detect access problems, we sought to reproduce angiographic results comparable to the gold standard angiogram (fistulogram) using ultrasound data acquired from a conventional 2D ultrasound scanner., Methods: A 2D ultrasound probe was used to acquire a series of cross sectional images of the vascular access including arteriovenous anastomosis of a subject with a radio-cephalic fistula. These 2D B-mode images were used for 3D vessel reconstruction by binary thresholding to categorize vascular versus non-vascular structures followed by standard image segmentation to select the structure representative of dialysis vascular access and morphologic filtering. Image processing was done using open source Python Software., Results: The open source software was able to: (1) view the gold standard fistulogram images, (2) reconstruct 2D planar images of the fistula from ultrasound data as viewed from the top, analogous to computerized tomography images, and (3) construct a 2D representation of vascular access similar to the angiogram., Conclusion: We present a simple approach to obtain an angiogram-like representation of the vascular access from readily available, non-proprietary 2D ultrasound data in the point of care setting. While the sono-angiogram is not intended to replace angiography, it may be useful in providing 3D imaging at the point of care in the dialysis unit, outpatient clinic, or for pre-operative planning for interventional procedures. Future work will focus on improving the robustness and quality of the imaging data while preserving the straightforward freehand approach used for ultrasound data acquisition.
- Published
- 2022
- Full Text
- View/download PDF
92. Semiautomated Software to Improve Stability and Reduce Operator-Induced Variation in Vascular Ultrasound Speckle Tracking.
- Author
-
Rajaram N, Thelen BJ, Hamilton JD, Zheng Y, Morgan T, Funes-Lora MA, Yessayan L, Shih AJ, Henke P, Osborne N, Bishop B, Krishnamurthy VN, and Weitzel WF
- Subjects
- Humans, Reproducibility of Results, Renal Dialysis methods, Software, Arteriovenous Shunt, Surgical, Kidney Failure, Chronic
- Abstract
Objectives: Ultrasound is useful in predicting arteriovenous fistula (AVF) maturation, which is essential for hemodialysis in end-stage renal disease patients. We developed ultrasound software that measures circumferential vessel wall strain (distensibility) using conventional ultrasound Digital Imaging and Communications in Medicine (DICOM) data. We evaluated user-induced variability in measurement of arterial wall distensibility and upon finding considerable variation we developed and tested 2 methods for semiautomated measurement., Methods: Ultrasound scanning of arteries of 10 subjects scheduled for AVF surgery were performed. The top and bottom of the vessel wall were tracked using the Kanade-Lucas-Tomasi (KLT) feature-tracking algorithm over the stack of images in the DICOM cine loops. The wall distensibility was calculated from the change of vessel diameter over time. Two semiautomated methods were used for comparison., Results: The location of points selected by users for the cine loops varied significantly, with a maximum spread of up to 120 pixels (7.8 mm) for the top and up to 140 pixels (9.1 mm) for the bottom of the vessel wall. This variation in users' point selection contributed to the variation in distensibility measurements (ranging from 5.63 to 41.04%). Both semiautomated methods substantially reduced variation and were highly correlated with the median distensibility values obtained by the 10 users., Conclusions: Minimizing user-induced variation by standardizing point selection will increase reproducibility and reliability of distensibility measurements. Our recent semiautomated software may help expand use in clinical studies to better understand the role of vascular wall compliance in predicting the maturation of fistulas., (© 2022 American Institute of Ultrasound in Medicine. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)
- Published
- 2022
- Full Text
- View/download PDF
93. Raman spectroscopy reveals phenotype switches in breast cancer metastasis.
- Author
-
Paidi SK, Troncoso JR, Harper MG, Liu Z, Nguyen KG, Ravindranathan S, Rebello L, Lee DE, Ivers JD, Zaharoff DA, Rajaram N, and Barman I
- Subjects
- Animals, Cell Line, Tumor, Melanoma, Mice, Neoplasm Metastasis, Phenotype, Skin Neoplasms, Melanoma, Cutaneous Malignant, Neoplasms, Second Primary, Spectrum Analysis, Raman
- Abstract
The accurate analytical characterization of metastatic phenotype at primary tumor diagnosis and its evolution with time are critical for controlling metastatic progression of cancer. Here, we report a label-free optical strategy using Raman spectroscopy and machine learning to identify distinct metastatic phenotypes observed in tumors formed by isogenic murine breast cancer cell lines of progressively increasing metastatic propensities. Methods: We employed the 4T1 isogenic panel of murine breast cancer cells to grow tumors of varying metastatic potential and acquired label-free spectra using a fiber probe-based portable Raman spectroscopy system. We used MCR-ALS and random forests classifiers to identify putative spectral markers and predict metastatic phenotype of tumors based on their optical spectra. We also used tumors derived from 4T1 cells silenced for the expression of TWIST, FOXC2 and CXCR3 genes to assess their metastatic phenotype based on their Raman spectra. Results: The MCR-ALS spectral decomposition showed consistent differences in the contribution of components that resembled collagen and lipids between the non-metastatic 67NR tumors and the metastatic tumors formed by FARN, 4T07, and 4T1 cells. Our Raman spectra-based random forest analysis provided evidence that machine learning models built on spectral data can allow the accurate identification of metastatic phenotype of independent test tumors. By silencing genes critical for metastasis in highly metastatic cell lines, we showed that the random forest classifiers provided predictions consistent with the observed phenotypic switch of the resultant tumors towards lower metastatic potential. Furthermore, the spectral assessment of lipid and collagen content of these tumors was consistent with the observed phenotypic switch. Conclusion: Overall, our findings indicate that Raman spectroscopy may offer a novel strategy to evaluate metastatic risk during primary tumor biopsies in clinical patients., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)
- Published
- 2022
- Full Text
- View/download PDF
94. Risk stratification and assessment framework for international travel and border measures amidst the COVID-19 pandemic - A Malaysian perspective.
- Author
-
Omar K, Baha Raja D, Abdul Taib NA, Rajaram N, Ahmed J, Arvinder-Singh HS, Mokhtar SA, Teo AKJ, Amir LE, Chan M, Quek YT, and Ting CY
- Subjects
- Humans, Pandemics prevention & control, Reproducibility of Results, Risk Assessment, Travel, COVID-19 epidemiology, COVID-19 prevention & control
- Abstract
Background: Guided by the best practices adapted from national and international bodies including the World Health Organization (WHO), the Centers for Disease Control (CDC), and the UK Joint Biosecurity Centre (JBC), this paper aims to develop and provide an empirical risk stratification and assessment framework for advancing the safe resumption of global travel during the COVID-19 pandemic., Method: Variables included in our model are categorized into four pillars: (i) incidence of cases, (ii) reliability of case data, (iii) vaccination, and (iv) variant surveillance. These measures are combined based on weights that reflect their corresponding importance in risk assessment within the context of the pandemic to calculate the risk score for each country. As a validation step, the outcome of the risk stratification from our model is compared against four countries., Results: Our model is found to have good agreement with these benchmarked risk designations for 27 out of the top 30 countries with the strongest travel ties to Malaysia (90%). Each factor within this model signifies its importance and can be adapted by governing bodies to address the changing needs of border control policies for the recommencement of international travel., Conclusion: In practice, the proposed model provides a turnkey solution for nations to manage transmission risk by enabling stakeholders to make informed, evidence-based decisions to minimize fluctuations of imported cases and serves as a structure to support the improvement, planning, and activation of public health control measures., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
95. Macrophage-targeted anti-CCL2 immunotherapy enhances tumor sensitivity to 5-fluorouracil in a Balb/c-CT26 murine colon carcinoma model measured using diffuse reflectance spectroscopy.
- Author
-
Bess SN, Greening GJ, Rajaram N, and Muldoon TJ
- Subjects
- Animals, Cell Line, Tumor, Fluorouracil therapeutic use, Humans, Immunotherapy, Macrophages, Mice, Mice, Inbred BALB C, Spectrum Analysis, Tumor Microenvironment, Carcinoma drug therapy, Colonic Neoplasms drug therapy
- Abstract
Background: Immunotherapy in colorectal cancer (CRC) regulates specific immune checkpoints and, when used in combination with chemotherapy, can improve patient prognosis. One specific immune checkpoint is the recruitment of circulating monocytes that differentiate into tumor-associated macrophages (TAMs) and promote tumor angiogenesis. Changes in vascularization can be non-invasively assessed via diffuse reflectance spectroscopy using hemoglobin concentrations and oxygenation in a localized tumor volume. In this study, we examine whether blockade of monocyte recruitment via CCL2 (macrophage chemoattractant protein-1) leads to enhanced sensitivity of 5-fluorouracil (5-FU) in a CT26-Balb/c mouse model of CRC. It was hypothesized that the blockade of TAMs will alter tumor perfusion, increasing chemotherapy response. A subcutaneous tumor model using Balb/c mice injected with CT26 colon carcinoma cells received either a saline or isotype control, anti-CCL2, 5-FU, or a combination of anti-CCL2 and 5-FU., Results: Findings show that 12 days post-treatment, monocyte recruitment was significantly reduced by approximately 61% in the combination group. This shows that the addition of anti-CCL2 to 5-FU slowed the fold-change (change from the original measurement to the final measurement) in tumor volume from Day 0 to Day 12 (~ 5 fold). Modest improvements in oxygen saturation (~ 30%) were observed in the combination group., Conclusion: The findings in this work suggest that the blockade of CCL2 is sufficient in the reduction of TAMs that are recruited into the tumor microenvironment and has the ability to modestly alter tumor perfusion during early-tumor response to treatment even though the overall benefit is relatively modest., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
96. Impact of COVID-19 on Basic Life Support Training Among Medical Students: An Experimental Study.
- Author
-
Rajaram N, Krishna H, Singh R, and Narayan AK
- Abstract
Aims and Objectives: Sudden cardiac death (SCD) is the most common cause of mortality worldwide. Bystander cardiopulmonary resuscitation (CPR) improves the victim's outcome, especially when the response time for advanced life support is prolonged. We performed a study to estimate the difference in knowledge among first-year medical students after basic life support (BLS) training (part of their foundation course) before and during the novel COVID-19 pandemic., Materials and Methods: We recruited first-year medical college students (batch of 2019-20: pre-COVID group - P and batch of 2020-21: COVID-19 era group - C) who were undergoing BLS training for the first time and consented to this study. Since the training was delayed and affected by COVID-19 for the batch of 2020-21, their training duration was shorter with more usage of audiovisual aids. The difference in the change in knowledge (by a questionnaire with 10 questions of one mark each) after training by the two methods was analysed. Analysis of variance, Wilcoxon signed-rank test, Mann-Whitney U test, and chi-square tests was used as applicable to compare the groups, and p-value <0.05 was considered significant. The results are analysed by IBM SPSS version 20.0 software (SPSS Inc, Chicago, IL, USA)., Results: The median (inter-quartile range) marks in group P (89 students) in the pre-test was 3 (4-2) and in the post-test was 6 (7-5) (out of 10). The corresponding marks in group C (112 students) in the pre-test were 3 (4-2) and in post-test was 7 (8-6). The knowledge improvement in group C was more with all the three changes being significant (p=0.0001). In group C, females had more improvement than males (p=0.0001)., Conclusion: We found a significant increase in the improvement of the knowledge after the BLS training in group C compared to group P. In group C, the improvement was better in females (59% increase in mean marks versus 22% in males)., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Rajaram et al.)
- Published
- 2022
- Full Text
- View/download PDF
97. Detecting High-Resolution Intramural Vascular Wall Strain Signals Using DICOM Data.
- Author
-
Weitzel WF, Thelen BJ, Rajaram N, Gao J, Hamilton J, Morgan T, Zheng Y, Funes-Lora MA, Krishnamurthy VN, Osborne N, Henke P, Bishop B, Yessayan L, and Shih AJ
- Subjects
- Humans, Ultrasonography methods, Kidney Failure, Chronic therapy
- Abstract
Maintaining dialysis vascular access is a source of considerable morbidity in patients with end-stage renal disease (ESRD). High-resolution radiofrequency (RF) ultrasound vascular strain imaging has been applied experimentally in the vascular access setting to assist in diagnosis and management. Unfortunately, high-resolution RF data are not routinely accessible to clinicians. In contrast, the standard DICOM formatted B-mode ultrasound data are widely accessible. However, B-mode, representing the envelope of the RF signal, is of much lower resolution. If strain imaging could use open-source B-mode data, these imaging techniques could be more broadly investigated. We conducted experiments to detect wall strain signals with submillimeter tracking resolutions ranging from 0.2 mm (3 pixels) to 0.65 mm (10 pixels) using DICOM B-mode data. We compared this submillimeter tracking to the overall vascular distensibility as the reference measurements to see if high-strain resolution strain could be detected using open-source B-Mode data. We measured the best-fit coefficient of determination between signals, expressed as the percentage of strain waveforms that exhibited a correlation with a p value of 0.05 or less. The lowest percentage was 86.7%, and most were 90% and higher. This indicates high-resolution strain signals can be detected within the vessel wall using B-mode DICOM data., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2021.)
- Published
- 2022
- Full Text
- View/download PDF
98. Ultrasound speckle tracking to detect vascular distensibility changes from angioplasty and branch ligation in a radio-cephalic fistula: Use of novel open source software.
- Author
-
Weitzel WF, Rajaram N, Zheng Y, Thelen BJ, Krishnamurthy VN, Hamilton J, Lora MAF, Morgan T, Shih AJ, and Yessayan L
- Subjects
- Aged, 80 and over, Angioplasty, Humans, Male, Renal Dialysis methods, Software, Treatment Outcome, Vascular Patency, Arteriovenous Shunt, Surgical adverse effects, Arteriovenous Shunt, Surgical methods, Fistula
- Abstract
We used novel open source software, based on an ultrasound speckle tracking algorithm, to examine the distensibility of the vessel wall of the inflow artery, anastomosis, and outflow vein before and after two procedures. An 83-year-old white man with a poorly maturing radio-cephalic fistula received an angioplasty at the anastomosis followed by branch ligation 28 days later. Duplex Doppler measurements corroborated the blood flow related changes anticipated from the interventions. The experimental distensibility results showed that it is technically feasible to measure subtle vessel wall motion changes with high resolution (sub-millimeter) using standard Digital Imaging and Communications in Medicine (DICOM) ultrasound data, which are readily available on conventional ultrasound scanners. While this methodology was originally developed using high resolution radiofrequency from ultrasound data, the goal of this study was to use DICOM data, which makes this technology accessible to a wide range of users.
- Published
- 2022
- Full Text
- View/download PDF
99. Ultrasound Measurement of Vascular Distensibility Based on Edge Detection and Speckle Tracking Using Ultrasound DICOM Data.
- Author
-
Funes-Lora MA, Thelen BJ, Shih AJ, Hamilton J, Rajaram N, Lyu J, Zheng Y, Morgan T, and Weitzel WF
- Subjects
- Carotid Arteries diagnostic imaging, Humans, Motion, Ultrasonography, Algorithms, Arteriovenous Shunt, Surgical
- Abstract
This study presents an edge detection and speckle tracking (EDST) based algorithm to calculate distensibility as percentage of change of vessel diameter during cardiac cycles. Canny edge detector, Vandermonde matrix representation, Kanade Lucas Tomasi algorithm with pyramidal segmentation, and penalized least squares technique identifies the vessel lumen edge, track the vessel diameter, detrend the signal and find peaks and valleys when the vessel is fully distended or contracted. An upper extremity artery from 10 patients underwent an ultrasound examination as part of preoperative evaluation before arteriovenous fistula surgery. Three studies were performed to evaluate EDST with automatic peak and valley selection versus manual speckle selection of expert users using manual peak and valley selection. Results demonstrate the effectiveness of the proposed methodology, to obtain comparable results as those obtained by expert-users, and considerably reducing the variability associated with external factors such as excessive motion, fluctuations in stroke volume, beat-to-beat blood pressure changes, breathing cycles, and arm-transducer pressure., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2021.)
- Published
- 2022
- Full Text
- View/download PDF
100. Raman Spectroscopy and Machine Learning Reveals Early Tumor Microenvironmental Changes Induced by Immunotherapy.
- Author
-
Paidi SK, Rodriguez Troncoso J, Raj P, Monterroso Diaz P, Ivers JD, Lee DE, Avaritt NL, Gies AJ, Quick CM, Byrum SD, Tackett AJ, Rajaram N, and Barman I
- Subjects
- Animals, Colonic Neoplasms drug therapy, Colonic Neoplasms metabolism, Colonic Neoplasms pathology, Immunotherapy methods, Mice, Mice, Inbred BALB C, Tumor Cells, Cultured, B7-H1 Antigen antagonists & inhibitors, CTLA-4 Antigen antagonists & inhibitors, Colonic Neoplasms immunology, Immune Checkpoint Inhibitors pharmacology, Machine Learning, Spectrum Analysis, Raman methods, Tumor Microenvironment
- Abstract
Cancer immunotherapy provides durable clinical benefit in only a small fraction of patients, and identifying these patients is difficult due to a lack of reliable biomarkers for prediction and evaluation of treatment response. Here, we demonstrate the first application of label-free Raman spectroscopy for elucidating biomolecular changes induced by anti-CTLA4 and anti-PD-L1 immune checkpoint inhibitors (ICI) in the tumor microenvironment (TME) of colorectal tumor xenografts. Multivariate curve resolution-alternating least squares (MCR-ALS) decomposition of Raman spectral datasets revealed early changes in lipid, nucleic acid, and collagen content following therapy. Support vector machine classifiers and random forests analysis provided excellent prediction accuracies for response to both ICIs and delineated spectral markers specific to each therapy, consistent with their differential mechanisms of action. Corroborated by proteomics analysis, our observation of biomolecular changes in the TME should catalyze detailed investigations for translating such markers and label-free Raman spectroscopy for clinical monitoring of immunotherapy response in cancer patients. SIGNIFICANCE: This study provides first-in-class evidence that optical spectroscopy allows sensitive detection of early changes in the biomolecular composition of tumors that predict response to immunotherapy with immune checkpoint inhibitors., (©2021 American Association for Cancer Research.)
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.