12 results on '"Sambandan D"'
Search Results
2. Sensorimotor dysfunction in multiple sclerosis and column-specific magnetization transfer-imaging abnormalities in the spinal cord
- Author
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Zackowski, K. M., primary, Smith, S. A., additional, Reich, D. S., additional, Gordon-Lipkin, E., additional, Chodkowski, B. A., additional, Sambandan, D. R., additional, Shteyman, M., additional, Bastian, A. J., additional, van Zijl, P. C., additional, and Calabresi, P. A., additional
- Published
- 2009
- Full Text
- View/download PDF
3. Identification of a small molecule with activity against drug-resistant and persistent tuberculosis
- Author
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Wang, F., Sambandan, D., Halder, R., Wang, J., Batt, S. M., Weinrick, B., Ahmad, I., Yang, P., Zhang, Y., Kim, J., Hassani, M., Huszar, S., Trefzer, C., Ma, Z., Kaneko, T., Mdluli, K. E., Franzblau, S., Chatterjee, A. K., Johnson, K., Mikusova, K., Besra, G. S., Futterer, K., Jacobs, W. R., and Schultz, P. G.
- Subjects
drug resistance ,dual mechanism ,bacterial infections and mycoses - Abstract
A cell-based phenotypic screen for inhibitors of biofilm formation in mycobacteria identified the small molecule TCA1, which has bactericidal activity against both drug-susceptible and -resistant Mycobacterium tuberculosis (Mtb) and sterilizes Mtb in vitro combined with rifampicin or isoniazid. In addition, TCA1 has bactericidal activity against nonreplicating Mtb in vitro and is efficacious in acute and chronic Mtb infection mouse models both alone and combined with rifampicin or isoniazid. Transcriptional analysis revealed that TCA1 down-regulates genes known to be involved in Mtb persistence. Genetic and affinity-based methods identified decaprenyl-phosphoryl-beta-D-ribofuranose oxidoreductase DprE1 and MoeW, enzymes involved in cell wall and molybdenum cofactor biosynthesis, respectively, as targets responsible for the activity of TCA1. These in vitro and in vivo results indicate that this compound functions by a unique mechanism and suggest that TCA1 may lead to the development of a class of antituberculosis agents.
4. Towards a Unified Management Interface for 5G Sensor Networks: Interoperability between Yet Another Next Generation and Open Platform Communication Unified Architecture.
- Author
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Sambandan D and Thirupathi D
- Abstract
Fifth-generation (5G) sensor networks are critical enablers of Industry 4.0, facilitating real-time monitoring and control of industrial processes. However, significant challenges to their deployment in industrial settings remain, such as a lack of support for interoperability and manageability with existing industrial applications and the specialized technical expertise required for the management of private 5G sensor networks. This research proposes a solution to achieve interoperability between private 5G sensor networks and industrial applications by mapping Yet Another Next Generation (YANG) models to Open Platform Communication Unified Architecture (OPC UA) models. An OPC UA pyang plugin, developed to convert YANG models into OPC UA design model files, has been made available on GitHub for open access. The key finding of this research is that the proposed solution enables seamless interoperability without requiring modifications to the private 5G sensor network components, thus enhancing the efficiency and reliability of industrial automation systems. By leveraging existing industrial applications, the management and monitoring of private 5G networks are streamlined. Unlike prior studies that explored OPC UA's integration with other protocols, this work is the first to focus on the YANG-OPC UA integration, filling a critical gap in Industry 4.0 enablement research.
- Published
- 2024
- Full Text
- View/download PDF
5. Development and Delivery of a Hands-On Short Course in Adeno-Associated Virus Manufacturing to Support Growing Workforce Needs in Gene Therapy.
- Author
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Overton L, Boi C, Shastry S, Smith-Moore C, Balchunas J, Sambandan D, and Gilleskie G
- Subjects
- Humans, Commerce, Genetic Vectors genetics, Dependovirus genetics, Genetic Therapy
- Abstract
The manufacturing of gene therapy products is a rapidly growing industry bolstered by the tremendous potential of these therapies to provide lifesaving treatment for rare and complex genetic diseases. The industry's steep rise has resulted in a high demand for skilled staff required to manufacture gene therapy products of the expected high quality. To address this skill shortage, more opportunities for education and training in all aspects of gene therapy manufacturing are needed. The Biomanufacturing Training and Education Center (BTEC) at the North Carolina State University (NC State) has developed and delivered (and continues to deliver) a 4-day, hands-on course titled Hands-on cGMP Biomanufacturing of Vectors for Gene Therapy. The course, which consists of 60% hands-on laboratory activities and 40% lectures, aims to provide a comprehensive understanding of the gene therapy production process, from vial thaw through the final formulation step, and analytical testing. This article discusses the design of the course, the backgrounds of the nearly 80 students who have participated in the seven offerings held since March 2019, and feedback from the course participants.
- Published
- 2023
- Full Text
- View/download PDF
6. Epigenome-wide association study of bronchopulmonary dysplasia in preterm infants: results from the discovery-BPD program.
- Author
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Wang X, Cho HY, Campbell MR, Panduri V, Coviello S, Caballero MT, Sambandan D, Kleeberger SR, Polack FP, Ofman G, and Bell DA
- Subjects
- Biomarkers, Birth Weight, DNA Methylation, Epigenome, Humans, Infant, Infant, Newborn, Infant, Premature, Bronchopulmonary Dysplasia genetics
- Abstract
Background: Bronchopulmonary dysplasia (BPD) is a lung disease in premature infants caused by therapeutic oxygen supplemental and characterized by impaired pulmonary development which persists into later life. While advances in neonatal care have improved survival rates of premature infants, cases of BPD have been increasing with limited therapeutic options for prevention and treatment. This study was designed to explore the relationship between gestational age (GA), birth weight, and estimated blood cell-type composition in premature infants and to elucidate early epigenetic biomarkers associated with BPD., Methods: Cord blood DNA from preterm neonates that went on to develop BPD (n = 14) or not (non-BPD, n = 93) was applied to Illumina 450 K methylation arrays. Blood cell-type compositions were estimated using DNA methylation profiles. Multivariable robust regression analysis elucidated CpGs associated with BPD risk. cDNA microarray analysis of cord blood RNA identified differentially expressed genes in neonates who later developed BPD., Results: The development of BPD and the need for oxygen supplementation were strongly associated with GA (BPD, p < 1.0E-04; O
2 supplementation, p < 1.0E-09) and birth weight (BPD, p < 1.0E-02; O2 supplementation, p < 1.0E-07). The estimated nucleated red blood cell (NRBC) percent was negatively associated with birth weight and GA, positively associated with hypomethylation of the tobacco smoke exposure biomarker cg05575921, and high-NRBC blood samples displayed a hypomethylation profile. Epigenome-wide association study (EWAS) identified 38 (Bonferroni) and 275 (false discovery rate 1%) differentially methylated CpGs associated with BPD. BPD-associated CpGs in cord blood were enriched for lung maturation and hematopoiesis pathways. Stochastic epigenetic mutation burden at birth was significantly elevated among those who developed BPD (adjusted p = 0.02). Transcriptome changes in cord blood cells reflected cell cycle, development, and pulmonary disorder events in BPD., Conclusions: While results must be interpreted with caution because of the small size of this study, NRBC content strongly impacted DNA methylation profiles in preterm cord blood and EWAS analysis revealed potential insights into biological pathways involved in BPD pathogenesis., (© 2022. The Author(s).)- Published
- 2022
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- View/download PDF
7. Identification of a small molecule with activity against drug-resistant and persistent tuberculosis.
- Author
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Wang F, Sambandan D, Halder R, Wang J, Batt SM, Weinrick B, Ahmad I, Yang P, Zhang Y, Kim J, Hassani M, Huszar S, Trefzer C, Ma Z, Kaneko T, Mdluli KE, Franzblau S, Chatterjee AK, Johnsson K, Mikusova K, Besra GS, Fütterer K, Robbins SH, Barnes SW, Walker JR, Jacobs WR Jr, and Schultz PG
- Subjects
- Alcohol Oxidoreductases, Amino Acid Sequence, Animals, Antitubercular Agents administration & dosage, Antitubercular Agents chemistry, Bacterial Proteins antagonists & inhibitors, Bacterial Proteins chemistry, Bacterial Proteins genetics, Benzothiazoles administration & dosage, Benzothiazoles chemistry, Biofilms drug effects, Biofilms growth & development, Carbohydrate Epimerases antagonists & inhibitors, Carbohydrate Epimerases chemistry, Carbohydrate Epimerases genetics, Drug Resistance, Bacterial, Female, Genes, Bacterial, High-Throughput Screening Assays, Isoniazid administration & dosage, Mice, Mice, Inbred BALB C, Microbial Sensitivity Tests, Molecular Sequence Data, Mycobacterium tuberculosis enzymology, Mycobacterium tuberculosis genetics, Oxidoreductases antagonists & inhibitors, Oxidoreductases chemistry, Oxidoreductases genetics, Rifampin administration & dosage, Thiophenes administration & dosage, Thiophenes chemistry, Tuberculosis, Pulmonary microbiology, Antitubercular Agents pharmacology, Benzothiazoles pharmacology, Mycobacterium tuberculosis drug effects, Thiophenes pharmacology, Tuberculosis, Pulmonary drug therapy
- Abstract
A cell-based phenotypic screen for inhibitors of biofilm formation in mycobacteria identified the small molecule TCA1, which has bactericidal activity against both drug-susceptible and -resistant Mycobacterium tuberculosis (Mtb) and sterilizes Mtb in vitro combined with rifampicin or isoniazid. In addition, TCA1 has bactericidal activity against nonreplicating Mtb in vitro and is efficacious in acute and chronic Mtb infection mouse models both alone and combined with rifampicin or isoniazid. Transcriptional analysis revealed that TCA1 down-regulates genes known to be involved in Mtb persistence. Genetic and affinity-based methods identified decaprenyl-phosphoryl-β-D-ribofuranose oxidoreductase DprE1 and MoeW, enzymes involved in cell wall and molybdenum cofactor biosynthesis, respectively, as targets responsible for the activity of TCA1. These in vitro and in vivo results indicate that this compound functions by a unique mechanism and suggest that TCA1 may lead to the development of a class of antituberculosis agents.
- Published
- 2013
- Full Text
- View/download PDF
8. Keto-mycolic acid-dependent pellicle formation confers tolerance to drug-sensitive Mycobacterium tuberculosis.
- Author
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Sambandan D, Dao DN, Weinrick BC, Vilchèze C, Gurcha SS, Ojha A, Kremer L, Besra GS, Hatfull GF, and Jacobs WR Jr
- Subjects
- Bacterial Proteins genetics, Gene Deletion, Antitubercular Agents pharmacology, Biofilms drug effects, Biofilms growth & development, Drug Tolerance, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis physiology, Mycolic Acids metabolism
- Abstract
ABSTRACT The chronic nature of tuberculosis (TB), its requirement of long duration of treatment, its ability to evade immune intervention, and its propensity to relapse after drug treatment is discontinued are reminiscent of other chronic, biofilm-associated bacterial diseases. Historically, Mycobacterium tuberculosis was grown as a pellicle, a biofilm-like structure, at the liquid-air interface in a variety of synthetic media. Notably, the most widely administered human vaccine, BCG, is grown as a pellicle for vaccine production. However, the molecular requirements for this growth remain ill defined. Here, we demonstrate that keto-mycolic acids (keto-MA) are essential for pellicle growth, and mutants lacking in or depleted of this MA species are unable to form a pellicle. We investigated the role of the pellicle biofilm in the reduction of antibiotic sensitivity known as drug tolerance using the pellicle-defective ΔmmaA4 mutant strain. We discovered that the ΔmmaA4 mutant, which is both pellicle defective and highly sensitive to rifampicin (RIF) under planktonic growth, when incorporated within the wild-type pellicle biofilm, was protected from the bactericidal activity of RIF. The observation that growth within the M. tuberculosis pellicle biofilm can confer drug tolerance to a drug-hypersensitive strain suggests that identifying molecular requirements for pellicle growth could lead to development of novel interventions against mycobacterial infections. Our findings also suggest that a class of drugs that can disrupt M. tuberculosis biofilm formation, when used in conjunction with conventional antibiotics, has the potential to overcome drug tolerance. IMPORTANCE Two of the most important questions in tuberculosis (TB) research are (i) how does Mycobacterium tuberculosis persist in the human host for decades in the face of an active immune response and (ii) why does it take six months and four drugs to treat uncomplicated TB. Both these aspects of M. tuberculosis biology are reminiscent of infections caused by organisms capable of forming biofilms. M. tuberculosis is capable of growing as a biofilm-like structure called the pellicle. In this study, we demonstrate that a specific cell wall component, keto-mycolic acid, is essential for pellicle growth. We also demonstrate that a strain of M. tuberculosis that is both drug sensitive and pellicle defective exhibits commensal behavior and becomes drug tolerant by becoming part of a heterogeneous pellicle, a characteristic of multispecies biofilms. These observations could have important implications for identifying novel pathways for M. tuberculosis drug tolerance and the design of new modalities to rapidly treat TB.
- Published
- 2013
- Full Text
- View/download PDF
9. Immunotherapy for cutaneous malignancy.
- Author
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Ibrahim SF, Sambandan D, and Ratner D
- Subjects
- Adoptive Transfer, Animals, Cancer Vaccines therapeutic use, Humans, Melanoma immunology, Melanoma therapy, Skin immunology, Skin Neoplasms immunology, Immunotherapy, Skin Neoplasms therapy
- Abstract
Background: Immunotherapy for cutaneous malignancy involves manipulating the immune system to treat and prevent skin cancer. Although initial efforts were fraught with low success rates and technical challenges, more-recent endeavors have yielded response rates approaching 50% for treating metastatic melanoma. Many of these advances are a result of increasing knowledge of the immune system's intricacies and continued progress in laboratory techniques., Objective: To review our current understanding of the skin immune system and discuss how these factors contribute to the host response to malignancy and to report the current state of immunotherapeutic techniques., Materials and Methods: An extensive PubMed literature search was conducted in topics involving immunotherapy with specific relevance to cutaneous malignancy using the MeSH terms "immunotherapy" and "skin cancer.", Results: Despite initially poor patient responses to these treatment modalities, recent gains in scientific knowledge and clinical intervention protocols have brought immunotherapy to the forefront of prospective skin cancer therapeutics, particularly for advanced melanoma., Conclusions: Current treatment options for advanced cutaneous malignancies such as melanoma are low in efficacy. Immunotherapies have the potential to provide novel approaches to address this, particularly when used in combination. The authors have indicated no significant interest with commercial supporters., (© 2011 by the American Society for Dermatologic Surgery, Inc.)
- Published
- 2011
- Full Text
- View/download PDF
10. Growth of Mycobacterium tuberculosis biofilms containing free mycolic acids and harbouring drug-tolerant bacteria.
- Author
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Ojha AK, Baughn AD, Sambandan D, Hsu T, Trivelli X, Guerardel Y, Alahari A, Kremer L, Jacobs WR Jr, and Hatfull GF
- Subjects
- Antitubercular Agents pharmacology, Biofilms drug effects, Carbon Dioxide metabolism, Humans, Iron metabolism, Lipids chemistry, Mycobacterium tuberculosis genetics, Mycobacterium tuberculosis metabolism, Mycolic Acids chemistry, Plankton chemistry, Plankton microbiology, Tuberculosis, Pulmonary drug therapy, Zinc metabolism, Biofilms growth & development, Drug Resistance, Bacterial, Mycobacterium tuberculosis drug effects, Mycobacterium tuberculosis physiology, Mycolic Acids metabolism, Tuberculosis, Pulmonary microbiology
- Abstract
Successful treatment of human tuberculosis requires 6-9 months' therapy with multiple antibiotics. Incomplete clearance of tubercle bacilli frequently results in disease relapse, presumably as a result of reactivation of persistent drug-tolerant Mycobacterium tuberculosis cells, although the nature and location of these persisters are not known. In other pathogens, antibiotic tolerance is often associated with the formation of biofilms--organized communities of surface-attached cells--but physiologically and genetically defined M. tuberculosis biofilms have not been described. Here, we show that M. tuberculosis forms biofilms with specific environmental and genetic requirements distinct from those for planktonic growth, which contain an extracellular matrix rich in free mycolic acids, and harbour an important drug-tolerant population that persist despite exposure to high levels of antibiotics.
- Published
- 2008
- Full Text
- View/download PDF
11. Phenotypic plasticity and genotype by environment interaction for olfactory behavior in Drosophila melanogaster.
- Author
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Sambandan D, Carbone MA, Anholt RR, and Mackay TF
- Subjects
- Animals, Behavior, Animal, Drosophila Proteins genetics, Environment, Female, Gene Expression Profiling, Genes, Insect, Genetic Complementation Test, Genetic Variation, Genotype, Male, Mutation, Oligonucleotide Array Sequence Analysis, Phenotype, Phylogeny, Quantitative Trait Loci, Reverse Transcriptase Polymerase Chain Reaction, Transferrin genetics, Drosophila melanogaster genetics, Drosophila melanogaster physiology, Smell genetics, Smell physiology
- Abstract
Genotype by environment interactions (GEI) play a major part in shaping the genetic architecture of quantitative traits and are confounding factors in genetic studies, for example, in attempts to associate genetic variation with disease susceptibility. It is generally not known what proportion of phenotypic variation is due to GEI and how many and which genes contribute to GEI. Behaviors are complex traits that mediate interactions with the environment and, thus, are ideally suited for studies of GEI. Olfactory behavior in Drosophila melanogaster presents an opportunity to systematically dissect GEI, since large numbers of genetically identical individuals can be reared under defined environmental conditions and the olfactory system of Drosophila and its behavioral response to odorants have been well characterized. We assessed variation in olfactory behavior in a population of 41 wild-derived inbred lines and asked to what extent different larval-rearing environments would influence adult olfactory behavior and whether GEI is a minor or major contributing source of phenotypic variation. We found that approximately 50% of phenotypic variation in adult olfactory behavior is attributable to GEI. In contrast, transcriptional analysis revealed that only 20 genes show GEI at the level of gene expression [false discovery rate (FDR) < 0.05], some of which are associated with physiological responses to environmental chemicals. Quantitative complementation tests with piggyBac-tagged mutants for 2 of these genes (CG9664 and Transferrin 1) demonstrate that genes that show transcriptional GEI are candidate genes for olfactory behavior and that GEI at the level of gene expression is correlated with GEI at the level of phenotype.
- Published
- 2008
- Full Text
- View/download PDF
12. Dynamic genetic interactions determine odor-guided behavior in Drosophila melanogaster.
- Author
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Sambandan D, Yamamoto A, Fanara JJ, Mackay TF, and Anholt RR
- Subjects
- Animals, DNA Transposable Elements genetics, Epistasis, Genetic, Mutagenesis, Insertional, Mutation, Odorants, Behavior, Animal, Drosophila melanogaster genetics, Drosophila melanogaster physiology, Genes, Insect, Smell genetics, Smell physiology
- Abstract
Understanding the genetic architecture of complex traits requires identification of the underlying genes and characterization of gene-by-gene and genotype-by-environment interactions. Behaviors that mediate interactions between organisms and their environment are complex traits expected to be especially sensitive to environmental conditions. Previous studies on the olfactory avoidance response of Drosophila melanogaster showed that the genetic architecture of this model behavior depends on epistatic networks of pleiotropic genes. We performed a screen of 1339 co-isogenic p[GT1]-element insertion lines to identify novel genes that contribute to odor-guided behavior and identified 55 candidate genes with known p[GT1]-element insertion sites. Characterization of the expression profiles of 10 p[GT1]-element insertion lines showed that the effects of the transposon insertions are often dependent on developmental stage and that hypomorphic mutations in developmental genes can elicit profound adult behavioral deficits. We assessed epistasis among these genes by constructing all possible double heterozygotes and measuring avoidance responses under two stimulus conditions. We observed enhancer and suppressor effects among subsets of these P-element-tagged genes, and surprisingly, epistatic interactions shifted with changes in the concentration of the olfactory stimulus. Our results show that the manifestation of epistatic networks dynamically changes with alterations in the environment.
- Published
- 2006
- Full Text
- View/download PDF
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