19 results on '"Shetty, Ajoy Prasad"'
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2. ISSLS PRIZE in basic science 2023: Lactate in lumbar discs—metabolic waste or energy biofuel? Insights from in vivo MRS and T2r analysis following exercise and nimodipine in healthy volunteers
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Pushpa, B. T., Rajasekaran, S., Easwaran, Murugesh, Murugan, Chandhan, Algeri, Raksha, Sri Vijay Anand, K. S., Mugesh Kanna, Rishi, and Shetty, Ajoy Prasad
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- 2023
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3. Are Modic changes ‘Primary infective endplatitis’?—insights from multimodal imaging of non-specific low back pain patients and development of a radiological 'Endplate infection probability score'.
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Rajasekaran, S., Pushpa, B. T., Soundararajan, Dilip Chand Raja, Sri Vijay Anand, K. S., Murugan, Chandhan, Nedunchelian, Meena, Kanna, Rishi Mugesh, Shetty, Ajoy Prasad, Tangavel, Chitraa, and Muthurajan, Raveendran
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- 2022
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4. The analysis of progression of disc degeneration in distal unfused segments and evaluation of long-term functional outcome in adolescent idiopathic scoliosis patients undergoing long-segment instrumented fusion
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Jakkepally, Sridhar, Viswanathan, Vibhu Krishnan, Shetty, Ajoy Prasad, Hajare, Swapnil, Kanna, Rishi Mukesh, and Rajasekaran, S.
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- 2022
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5. Human intervertebral discs harbour a unique microbiome and dysbiosis determines health and disease
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Rajasekaran, Shanmuganathan, Soundararajan, Dilip Chand Raja, Tangavel, Chitraa, Muthurajan, Raveendran, Sri Vijay Anand, K. S., Matchado, Monica Steffi, Nayagam, Sharon Miracle, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, and Dharmalingam, K.
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- 2020
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6. A Whole Spine MRI Based Study of the Prevalence, Associated Disc Degeneration and Anatomical Correlations of Lumbosacral Transitional Vertebra.
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Bhagchandani, Chintan, Murugan, Chandhan, Jakkepally, Sridhar, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, and Rajasekaran, Shanmuganathan
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RENAL artery ,ABDOMINAL aorta ,ANATOMICAL variation ,VERTEBRAE ,CONUS - Abstract
Study Design: Retrospective cohort study. Objective: Lumbosacral transitional vertebra (LSTV) results in numerical alterations of the lumbar and sacral segments. Literature concerning true prevalence, associated disc degeneration, and variation in numerous anatomical landmarks concerning LSTV is lacking. Methods: This is a retrospective cohort study. The prevalence of LSTV was determined in whole spine MRIs of 2011 poly-trauma patients. LSTV was identified as sacralization (LSTV-S) or lumbarization (LSTV-L) and further sub-classified into Castellvi's and O'Driscoll's type respectively. Disc degeneration was evaluated using Pfirmann grading. Variation in important anatomical landmarks was also analysed. Results: Prevalence of LSTV was 11.6% with 82% having LSTV-S. Castellvi's type 2A and O'Driscoll type 4 were the commonest sub-types. LSTV patients demonstrated considerably advanced disc degeneration. The median termination level of conus medullaris (TLCM) in non- LSTV and LSTV-L groups was at middle L1 (48.1% and 40.2%) while in the LSTV-S group, it was at upper L1 (47.2%). The median level of right renal artery (RRA) in non- LSTV patients was at middle L1 in 40.0% of individuals while in the LSTV-L and LSTV-S groups, it was at upper L1 level in 35.2% and 56.2% respectively. The median level of abdominal aortic bifurcation (AA) in non-LSTV and LSTV-S patients was at middle L4 in 83.3% and 52.04% respectively. However, in the LSTV-L group, the most common level was middle L5 (53.6%). Conclusion: The overall prevalence of LSTV was 11.6%, with sacralization accounting for more than 80%. LSTV is associated with disc degeneration and a variation in the levels of important anatomical landmarks. [ABSTRACT FROM AUTHOR]
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- 2024
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7. ISSLS PRIZE IN CLINICAL SCIENCE 2017: Is infection the possible initiator of disc disease? An insight from proteomic analysis
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Rajasekaran, S., Tangavel, Chitraa, Aiyer, Siddharth N., Nayagam, Sharon Miracle, Raveendran, M., Demonte, Naveen Luke, Subbaiah, Pramela, Kanna, Rishi, Shetty, Ajoy Prasad, and Dharmalingam, K.
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- 2017
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8. Genetic susceptibility of lumbar degenerative disc disease in young Indian adults
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Rajasekaran, S., Kanna, Rishi Mugesh, Senthil, Natesan, Raveendran, Muthuraja, Ranjani, Veera, Cheung, Kenneth M. C., Chan, Danny, Kao, Patrick Y. P., Yee, Anita, and Shetty, Ajoy Prasad
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- 2015
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9. Proteomic Signature of Nucleus Pulposus in Fetal Intervertebral Disc.
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Rajasekaran, Shanmuganathan, Soundararajan, Dilip Chand Raja, Tangavel, Chitraa, K. S., Sri Vijay Anand, Nayagam, Sharon Miracle, Matchado, Monica Steffi, Muthurajan, Raveendran, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, and Dharmalingam, K.
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NUCLEUS pulposus ,INTERVERTEBRAL disk ,PROTEIN disulfide isomerase ,PROTEOMICS ,RIBOSOMAL proteins - Abstract
Study Design: Profiling proteins expressed in the nucleus pulposus of fetal intervertebral disc (IVD). Purpose: To evaluate the molecular complexity of fetal IVDs not exposed to mechanical, traumatic, inflammatory, or infective insults to generate improved knowledge on disc homeostasis. Overview of Literature: Low back pain is the most common musculoskeletal disorder, causing a significant reduction in the quality of life, and degenerative disc disorders mainly contribute to the increasing socioeconomic burden. Despite extensive research, the causative pathomechanisms behind degenerative disc disorders are poorly understood. Precise molecular studies on the intricate biological processes involved in maintaining normal disc homeostasis are needed. Methods: IVDs of nine fetal specimens obtained from medical abortions were used to dissect out the annulus fibrosus and nucleus pulposus under sterile operating conditions. Dissected tissues were transferred to sterile Cryovials and snap frozen in liquid nitrogen before transporting to the research laboratory for protein extraction and further liquid chromatography tandem mass spectrometry (LCMS/ MS) analysis. Collected data were further analyzed using Gene Functional Classification Tool in DAVID and STRING databases. Results: A total of 1,316 proteins were identified through LC-MS/MS analysis of nine fetal IVD tissues. Approximately 247 proteins present in at least four fetal discs were subjected to further bioinformatic analysis. The following 10 clusters of proteins were identified: collagens, ribosomal proteins, small leucine-rich proteins, matrilin and thrombospondin, annexins, protein disulfide isomerase family proteins and peroxiredoxins, tubulins, histones, hemoglobin, and prolyl 4-hydroxylase family proteins. Conclusions: This study provides fundamental information on the proteome networks involved in the growth and development of healthy fetal discs in humans. Systematic cataloging of proteins involved in various structural and regulatory processes has been performed. Proteins expressed most abundantly (collagen type XIV alpha 1 chain, biglycan, matrilin 1, and thrombospondin 1) in their respective clusters also elucidate the possibility of utilizing these proteins for potential regenerative therapies. [ABSTRACT FROM AUTHOR]
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- 2020
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10. Patterns of lumbar disc degeneration are different in degenerative disc disease and disc prolapse magnetic resonance imaging analysis of 224 patients.
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Kanna, Rishi M., Shetty, Ajoy Prasad, and Rajasekaran, S.
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LUMBAR vertebrae diseases , *DEGENERATION (Pathology) , *MAGNETIC resonance imaging , *SYMPTOMS , *ETIOLOGY of diseases , *RADIOLOGY - Abstract
Abstract: Background context: Existing research on lumbar disc degeneration has remained inconclusive regarding its etiology, pathogenesis, symptomatology, prevention, and management. Degenerative disc disease (DDD) and disc prolapse (DP) are common diseases affecting the lumbar discs. Although they manifest clinically differently, existing studies on disc degeneration have included patients with both these features, leading to wide variations in observations. The possible relationship or disaffect between DDD and DP is not fully evaluated. Purpose: To analyze the patterns of lumbar disc degeneration in patients with chronic back pain and DDD and those with acute DP. Study design: Prospective, magnetic resonance imaging–based radiological study. Methods: Two groups of patients (aged 20–50 years) were prospectively studied. Group 1 included patients requiring a single level microdiscectomy for acute DP. Group 2 included patients with chronic low back pain and DDD. Discs were assessed by magnetic resonance imaging through Pfirmann grading, Schmorl nodes, Modic changes, and the total end-plate damage score for all the five lumbar discs. Results: Group 1 (DP) had 91 patients and group 2 (DDD) had 133 patients. DP and DDD patients differed significantly in the number, extent, and severity of degeneration. DDD patients had a significantly higher number of degenerated discs than DP patients (p<.000). The incidence of multilevel and pan-lumbar degeneration was also significantly higher in DDD group. The pattern of degeneration also differed in both the groups. DDD patients had predominant upper lumbar involvement, whereas DP patients had mainly lower lumbar degeneration. Modic changes were more common in DP patients, especially at the prolapsed level. Modic changes were present in 37% of prolapsed levels compared with 9.9% of normal discs (p<.00). The total end-plate damage score had a positive correlation with disc degeneration in both the groups. Further the mean total end-plate damage score at prolapsed level was also significantly higher. Conclusion: The results suggest that patients with disc prolapse, and those with back pain with DDD are clinically and radiologically different groups of patients with varying patterns, severity, and extent of disc degeneration. This is the first study in literature to compare and identify significant differences in these two commonly encountered patient groups. In patients with single-level DP, the majority of the other discs are nondegenerate, the lower lumbar spine is predominantly involved and the end-plate damage is higher. Patients with back pain and DDD have larger number of degenerate discs, early multilevel degeneration, and predominant upper lumbar degeneration. The knowledge that these two groups of patients are different clinically and radiologically is critical for our improved understanding of the disease and for future studies on disc degeneration and disc prolapse. [Copyright &y& Elsevier]
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- 2014
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11. Does the gut microbiome influence disc health and disease? The interplay between dysbiosis, pathobionts, and disc inflammation: a pilot study.
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Rajasekaran, Shanmuganathan, Vasudevan, Gowdaman, Tangavel, Chitraa, Ramachandran, Karthik, Nayagam, Sharon Miracle, Muthurajan, Raveendran, Gopalakrishnan, Chellappa, Anand, Sri Vijay, Shetty, Ajoy Prasad, and Kanna, Rishi Mugesh
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FATTY acid-binding proteins , *PROTEOMICS , *SHORT-chain fatty acids , *BLOOD proteins , *GUT microbiome - Abstract
Gut microbiome alterations resulting in inflammatory responses have been implicated in many distant effects on different organs. However, its influence on disc health is still not fully investigated. Our objective was to document the gut biome in healthy volunteers and patients with disc degeneration and to understand the role of gut dysbiosis on human disc health. Experimental case-control study. We included 40 patients with disc degeneration (DG) and 20 healthy volunteers (HV). HV comprised of age groups 30 to 60 years with no known record of back pain and no clinical comorbidities, with normal MRI. Diseased group (DG) were patients in the same age group undergoing surgery for disc disease (disc herniation-25; discogenic stenosis-15) and without instability (with Modic-20; and non-Modic-20). N/A. We analyzed 16S V3-V4 rDNA gut metagenome from 20 healthy volunteers (HV) and compared the top signature genera from 40 patients with disc degeneration (DG) across Modic and non-Modic groups. Norgen Stool DNA Kit was used for DNA extraction from ∼200 mg of each faecal sample collected using the Norgen Stool Collection Kit.16S V3-V4 rDNA amplicons were generated with universal bacterial primers 341F and 806R and amplified with Q5 High-Fidelity DNA Polymerase. Libraries were sequenced with 250×2 PE to an average of 0.1 million raw reads per sample (Illumina Novaseq 6000). Demultiplexed raw data was assessed with FastQC, and adapter trimmed reads >Q30 reads were processed in the QIME2 pipeline. Serum C-reactive protein (CRP) was measured by the immunoturbimetry method and Fatty acid-binding protein 5 (FABP5) was measured in albumin-globulin-depleted plasma through global proteome analysis. We observed significant gut dysbiosis between HV and DG and also between the Modic and non-Modic groups. In the Modic group, commensals Bifidobacterium and Ruminococcus were significantly depleted, while pathobionts Streptococcus, Prevotella, and Butryvibrio were enriched. Firmicutes/Bacteroidetes ratio was decreased in DG (Modic-0.62, non-Modic-0.43) compared to HV (0.70). Bacteria-producing beneficial short-chain fatty acids were also depleted in DG. Elevated serum CRP and increased FABP5 were observed in DG. The study revealed gut dysbiosis, an altered Firmicutes/Bacteroidetes ratio, reduced SCFA-producing bacteria, and increased systemic and local inflammation in association with disc disease, especially in Modic changes. The findings have considerable importance for our understanding and prevention of disc degeneration. [ABSTRACT FROM AUTHOR]
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- 2024
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12. A Whole-Spine Magnetic Resonance Imaging–Based Cross-Sectional Study of the Clinicoradiological Association of Lumbosacral Transitional Vertebra with Degenerative Disc Disease, End Plate Degeneration, Low Back Pain, and Facet Tropism.
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Bhagchandani, Chintan, Murugan, Chandhan, Arumugam, Thirumurugan, Karuppanan Sukumaran, Sri Vijay Anand, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, and Rajasekaran, Shanmuganathan
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LUMBAR pain , *MAGNETIC resonance , *DEGENERATION (Pathology) , *TROPISMS , *MAGNETIC resonance imaging - Abstract
To understand lumbosacral transitional vertebra (LSTV)–associated degenerative pathologies and their correlation to low back pain and radicular pain. Whole-spine magnetic resonance imaging was evaluated for disc degeneration using Pfirrmann grading, end plate changes using total end plate score (TEPS), and facet tropism in patients with low back pain and radicular pain, and their association with LSTV was analyzed. In group 1, LSTV was seen in 15% of patients with 83% of these patients having sacralization. Disc degeneration was seen in 58%, 51%, and 63% of patients at levels C, B, and A, respectively; patients with sacralization had significant degeneration at all 3 levels. Similarly, the total end plate score and facet tropism were significantly higher in patients with sacralization. Facet tropism was observed in 31%, 40%, and 35% of patients with no -LSTV, patients with sacralization, and patients with lumbarization, respectively. In group 2, LSTV was seen in 17% of patients with sacralization accounting for 82%. Disc degeneration was seen in 44%, 36%, and 54% patients at levels C, B, and A, respectively. No significant difference was observed in the mean total end plate score between groups. Facet tropism was identified in 89% and 81% of patients with sacralization and patients with lumbarization, respectively, compared with only 19% of patients with no LSTV. Patients with low back pain had a higher incidence of sacralization with corresponding disc degeneration, facet tropism ,and end plate changes. In patients with radicular pain, lumbarization was associated only with facet tropism. These findings may aid clinicians in prognostication and patient counseling. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Evaluation of Disc and Endplate Degeneration in AO Type A Fractures Using Magnetic Resonance Imaging Analysis.
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Subramanian, Preetish, Ramachandran, Karthik, Arumugam, Thirumurugan, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, and Shanmuganathan, Rajasekaran
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MAGNETIC resonance imaging , *IMAGE analysis , *VERTEBRAL fractures , *STATURE - Abstract
Disc degeneration after trauma has been the focus of several investigations, although vertebral endplate changes have received comparatively less attention. The main aim of the present study is to radiologically evaluate the prevalence of the degree of degeneration of the adjacent discs and endplates after AO type A thoracolumbar fractures. We retrospectively reviewed 25 patients with an AO type A injury (50 discs and 150 endplates). The type of disc lesion adjacent to the fractured vertebra was classified using the Pfirrmann and Oner classifications immediately after trauma and at the 1-year follow-up. The endplate defects were assessed using the endplate scoring system (total endplate score 1–6) in T1-weighted images. The kyphosis angle and vertebral body height were also measured. The study population consisted of 18 men (72%) and 7 women (28%), with a mean age of 38.9 ± 11.3 years. Overall, 28% of the fractures were type A1, 4% were type A2, 24% were type A3, and 44% were type A4. On statistical analysis, a significant change was found in the degree of degeneration in the cranial adjacent disc using both the Oner (P = 0.004) and Pfirrmann (P = 0.001) classifications at the end of 1 year. The morphological changes at the cranial adjacent discs at 1 year of follow-up showed a strong positive correlation with superior endplate degeneration. The results from the present study indicate that endplate fractures of vertebrae in patients with thoracolumbar burst fractures can cause disc degeneration, especially at the cranial endplate. [ABSTRACT FROM AUTHOR]
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- 2023
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14. "Are we barking up the wrong tree? Too much emphasis on Cutibacterium acnes and ignoring other pathogens"— a study based on next-generation sequencing of normal and diseased discs.
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Rajasekaran, Shanmuganathan, Vasudevan, Gowdaman, Easwaran, Murugesh, Devi Ps, Narmatha, Anand K S, Sri Vijay, Muthurajan, Raveendran, Tangavel, Chitraa, Murugan, Chandhan, B T, Pushpa, Shetty, Ajoy Prasad, and Kanna, Rishi Mugesh
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CUTIBACTERIUM acnes , *NUCLEOTIDE sequencing , *GRAM-negative bacteria , *LIQUID chromatography-mass spectrometry , *BACTERIAL metabolites , *GRAM-positive bacteria - Abstract
The majority of literature on bacterial flora in the disc stands disadvantaged in utilizing traditional culture methods and targeting a single bacterium , Cutibacterium acnes. Our objective was to document the diversity in the bacterial flora between normal and degenerated discs for shortlisting potential pathogens using next-generation genomic tools. Experimental case-control study. Researchers employed 16S metagenome sequencing to profile bacterial diversity in magnetic resonance imaging normal healthy discs from brain-dead organ voluntary donors (n=20) and 40 degenerated disc samples harvested during surgery (Modic [MC]=20 and non-Modic [NMC]=20). The V3-V4 region was amplified using universal bacterial primers 341F and 806R, and the libraries were sequenced using Illumina NovoSeq 6000 platform. Statistical significance was set at bacteria with a minimum of 100 operational taxonomic unit (OTU) and present in at least 70% of the samples. The quality check-filtered reads were processed using the QIIME-2 pipeline. The OTU clustering and taxonomic classification were carried out for the merged reads using the Greengenes/SILVA reference database. Validation was done by identification of bacterial metabolites in samples using the liquid chromatography–mass spectrometry approach. Abundant bacteria differing widely in diversity, as evidenced by Alfa and Beta diversity analysis, were present in all control and degenerative samples. The number of bacterial genera was 27 (14-gram-positive: 13-gram-negative) in the control group, 23 (10-gram-positive: 11-gram-negative) in the Modic group, and 16 (11-gram-positive: 5-gram-negative) in the non-Modic group. In the Modic group, gram-negative bacteria OTUs were found to be predominant (more than 50% of the total bacteria identified), whereas in control and non-Modic groups the OTUs of gram-positive bacteria were predominant. Species-level analysis revealed an abundance of opportunistic gram-negative pathogens like Pseudomonas aeruginosa, Sphingomonos paucibacillus , and Ochrobactrum quorumnocens in the discs with Modic changes, more than in non-Modic discs. The presence of bacterial metabolites and quorum-sensing molecules like N-decanoyl-L-homoserine lactone, 6-hydroxynicotinic acid, 2-aminoacetophenone, 4-hydroxy-3-polyprenylbenzoate, PE (16:1(9Z)/18:0) and phthalic acid validated the colonization and cell-cell communication of bacteria in disc ruling out contamination theory. Cutibacterium acnes was not the predominant bacteria in any of the three groups of discs and in fact was in the 16th position in the order of abundance in the control discs (0.72%), seventh position in the Modic discs (1.41%), and 12th position (0.53%) in the non-Modic discs. This study identified a predominance of gram-negative bacteria in degenerated discs and highlights that Cutibacterium acnes may not be the only degeneration-causing bacteria. This may be attributed to the environment, diet, and lifestyle habits of the sample population. Though the study does not reveal the exact pathogen, it may pave the way for future studies on the subject. These findings invite further investigation into causal relationships of bacterial profile with disc degeneration phenotypes as well as phenotype-driven clinical treatment protocols. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Bacteria in human lumbar discs – subclinical infection or contamination? Metabolomic evidence for colonization, multiplication, and cell-cell cross-talk of bacteria.
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Rajasekaran, Shanmuganathan, Tangavel, Chitraa, Vasudevan, Gowdaman, Easwaran, Murugesh, Muthurajan, Raveendran, K S, Sri Vijay Anand, Murugan, Chandhan, Nayagam, Sharon Miracle, Kanna, Rishi Mugesh, and Shetty, Ajoy Prasad
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BACTERIAL metabolites , *REVERSE phase liquid chromatography , *METABOLOMICS , *MICROBIAL metabolites , *PROTON magnetic resonance spectroscopy , *LUMBAR pain , *QUORUM sensing - Abstract
The accumulating evidence associating sub-clinical infection with disc degeneration (DD) and the controversy of contamination versus infection mandates a further understanding of the microbial activity in the disc and host-microbiome interaction. To utilize a novel approach of metabolomics to probe the presence of bacterial metabolites involved in colonization, survival, and replication in human lumbar intervertebral discs (LIVD). An observational case-control study. Nucleus pulposus from the LIVD of three brain-dead voluntary organ donors (MRI normal and classified as controls) and of three patients undergoing surgery for disc degeneration (DD) (cases) were utilized. Untargeted metabolite profiling was carried out in six discs (3-controls and 3-cases) after extraction using methanol: acetonitrile: water (2:2:1) solvent system and acquired through HPLC-MS/MS platform using C18 reversed-phase column. From the total IVD metabolome, microbial metabolites were filtered by mapping against HMDB, ChEBI, SigMol, Siderophore database, ecdmb database, and PaMet databases. The biological functions of the metabolites were then studied by MSEA pipeline from Metaboanalyst, and the enrichment ratio, p-value, and Variably Importance Projection scores of the metabolites were calculated. Degeneration responsive changes in the abundance of the microbial metabolites were calculated based on the peak intensities between the control and cases. Mass spectrometry identified a total of 17601 and 15003 metabolites, respectively, in the control and degenerated discs. Preliminary mapping of the above metabolites against HMDB indicated the multiple sources, and of these, 64 metabolites were of microbial origin, accounting for 1.6% of the total IVD metabolome. Principle Component Analysis and Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA) showed distinct clustered patterns between control and disc degene'ration, indicating a strong variation in concentration, peak, and spectral values of the 64 metabolites between controls and cases. After the exclusion of metabolites that were also associated with humans, drugs, and food, 39 metabolites specific to bacteria were isolated. Nine were primary metabolites related to bacterial growth and survival, and the remaining 30 were secondary metabolites related to different environmental stress response activities. The three significant pathways (p<.001) which were predominant in the bacterial metabolites were autoinducer-2 biosynthesis, peptidoglycan biosynthesis, and chorismate pathway. In addition, a significant fold change of >1.0 was found for nine metabolites which included (S)-14-Methyilhexadecanoic acid related to P. acnes , 9-OxoODE, and 13-OxoODE related to gut flora, vibriobactin – a siderophore, tuberculosinol and iso-tuberculosinol, virulence factors of M. tuberculosis. There was also upregulation of Autoinducer- 2, an important "Quorum sensing molecule" involved in bacterial cross-talk. We identified several bacterial-specific metabolites participating in bacterial growth, survival, and cross-talk pathways. These were found in both groups but up-regulated in degenerated discs. The presence of Quorum sensing molecules and cell-cell interactions provides firm proof of colonization and growth. These findings indicate that the bacterial presence may not be mere contamination but could be colonization with a possible role in infection-mediated inflammation in DD. Proof of subclinical infection as an initiator of DD and documentation of exact germ and drug sensitivity will change the way millions of patients with non-specific low back pain (NSLBP) are treated across the world. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Inflammaging determines health and disease in lumbar discs-evidence from differing proteomic signatures of healthy, aging, and degenerating discs.
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Rajasekaran, S., Tangavel, Chitraa, K.S., Sri Vijay Anand, Soundararajan, Dilip Chand Raja, Nayagam, Sharon Miracle, Matchado, Monica Steffi, Raveendran, M, Shetty, Ajoy Prasad, Kanna, Rishi Mugesh, Dharmalingam, K., Anand, Sri Vijay, and Raja, Dilip Chand
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INTERVERTEBRAL disk , *COMPLEMENT inhibition , *COMPLEMENT activation , *PROTEIN expression , *DISCECTOMY , *GENE ontology , *RESEARCH , *SPINE diseases , *RESEARCH methodology , *EVALUATION research , *MEDICAL cooperation , *PROTEOMICS , *LUMBAR vertebrae , *COMPARATIVE studies , *AGING - Abstract
Background Context: The true understanding of aging and disc degeneration (DD) is still elusive. MRI has not helped our attempts to understand the health and disease status of the discs as it reflects mainly the end morphologic changes and not the changes at a molecular level. Understanding degeneration at a molecular level through proteomics might allow differentiation from normal aging and also aid in the development of biomarkers for early diagnosis and preventive therapies.Purpose: To utilize proteomics to understand the molecular basis of healthy, aging, and degenerating discs and conclusively differentiate normal aging and degeneration.Study Design: Proteomic analysis of human intervertebral disc samples.Methods: L4-L5 disc samples from three groups were acquired and subjected to proteomic analysis. Samples from individuals aged in the second, third, and fourth decades were used to represent young healthy discs (Group A). Those from MRI normal donors aged in the fifth, sixth, and seventh decades represented normal aging (Group B). Five degenerated discs obtained from patients at surgery represented degeneration (Group C). The entire proteome map and alteration in protein expressions were further analyzed using bioinformatics analysis. This was a self-funded project.Results: There were 84 common proteins. Specific proteins numbered 225 in A, 315 in B, and 283 in C. By gene ontology biological process identification, Group A predominated with extracellular matrix organization, cytoskeletal structural and normal metabolic proteins. Group B differed in having additional basal expression of immune response, complement inhibitors, and senescence proteins. Group C was different, with upregulation of proteins associated with oxidative stress response, positive regulators of apoptosis, innate immune response, complement activation and defense response to gram positive bacteria indicating ongoing inflammaging.Conclusions: Our study documented diverse proteome signatures between the young, aging and degenerating discs. Inflammaging was the main differentiator between normal biological aging and DD.Clinical Significance: Multiple inflammatory molecules unique to DD were identified, allowing the possibility of developing specific biomarkers for early diagnosis and thereby provide evidence-based metrics for preventive measures rather than surgical intervention and also to monitor progress of the disease. [ABSTRACT FROM AUTHOR]- Published
- 2020
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17. How Reliable Are the Reported Genetic Associations in Disc Degeneration?: The Influence of Phenotypes, Age, Population Size, and Inclusion Sequence in 809 Patients.
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Rajasekaran, S., Kanna, Rishi Mugesh, Reddy, Ranjani Raja, Natesan, Senthil, Raveendran, Muthuraja, Cheung, Kenneth M. C., Chan, Danny, Kao, Patrick Y. P., Yee, Anita, and Shetty, Ajoy Prasad
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SPINAL cord injuries , *THERAPEUTICS , *NEURODEGENERATION , *SPINAL cord regeneration , *SINGLE nucleotide polymorphisms , *MAGNETIC resonance imaging , *AGE distribution , *CELL receptors , *DISEASE susceptibility , *GENETIC polymorphisms , *GENETIC techniques , *HYDROLASES , *INTERVERTEBRAL disk , *SPINE diseases , *PROTEINS , *PROTEOLYTIC enzymes , *PHENOTYPES , *CROSS-sectional method - Abstract
Study Design: Prospective genetic association study.Objective: The aim of this study was to document the variations in the genetic associations, when different magnetic resonance imaging (MRI) phenotypes, age stratification, cohort size, and sequence of cohort inclusion are varied in the same study population.Summary Of Background Data: Genetic associations with disc degeneration have shown high inconsistency, generally attributed to hereditary factors and ethnic variations. However, the effect of different phenotypes, size of the study population, age of the cohort, etc have not been documented clearly.Methods: Seventy-one single-nucleotide polymorphisms (SNPs) of 41 candidate genes were correlated to six MRI markers of disc degeneration (annular tears, Pfirmann grading, Schmorl nodes, Modic changes, Total Endplate Damage score, and disc bulge) in 809 patients with back pain and/or sciatica. In the same study group, the correlations were then retested for different age groups, different sample, size and sequence of subject inclusion (first 404 and the second 405) and the differences documented.Results: The mean age of population (M: 455, F: 354) was 36.7 ± 10.8 years. Different genetic associations were found with different phenotypes: disc bulge with three SNPs of CILP; annular tears with rs2249350 of ADAMTS5 and rs11247361 IGF1R; modic changes with VDR and MMP20; Pfirmann grading with three SNPs of MMP20 and Schmorl node with SNPs of CALM1 and FN1 and none with Total End Plate Score.Subgroup analysis based on three age groups and dividing the total population into two groups also completely changed the associations for all the six radiographic parameters.Conclusion: In the same study population, SNP associations completely change with different phenotypes. Variations in age, inclusion sequence, and sample size resulted in change of genetic associations. Our study questions the validity of previous studies and necessitates the need for standardizing the description of disc degeneration, phenotype selection, study sample size, age, and other variables in future studies.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]- Published
- 2016
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18. Phenotype variations affect genetic association studies of degenerative disc disease: conclusions of analysis of genetic association of 58 single nucleotide polymorphisms with highly specific phenotypes for disc degeneration in 332 subjects.
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Rajasekaran, S., Kanna, Rishi Mugesh, Senthil, Natesan, Raveendran, Muthuraja, Cheung, Kenneth M.C., Chan, Danny, Subramaniam, Sakthikanal, and Shetty, Ajoy Prasad
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OSTEOARTHRITIS , *PHENOTYPES , *SINGLE nucleotide polymorphisms , *INTERVERTEBRAL disk diseases , *SPINE radiography , *HERNIA , *GENETICS - Abstract
Abstract: Background context: Although the influence of genetics on the process of disc degeneration is well recognized, in recently published studies, there is a wide variation in the race and selection criteria for such study populations. More importantly, the radiographic features of disc degeneration that are selected to represent the disc degeneration phenotype are variable in these studies. The study presented here evaluates the association between single nucleotide polymorphisms (SNPs) of candidate genes and three distinct radiographic features that can be defined as the degenerative disc disease (DDD) phenotype. Purpose: The study objectives were to examine the allelic diversity of 58 SNPs related to 35 candidate genes related to lumbar DDD, to evaluate the association in a hitherto unevaluated ethnic Indian population that represents more than one-sixth of the world population, and to analyze how genetic associations can vary in the same study subjects with the choice of phenotype. Study design: A cross-sectional, case-control study of an ethnic Indian population was carried out. Methods: Fifty-eight SNPs in 35 potential candidate genes were evaluated in 342 subjects and the associations were analyzed against three highly specific markers for DDD, namely disc degeneration by Pfirrmann grading, end-plate damage evaluated by total end-plate damage score, and annular tears evaluated by disc herniations and hyperintense zones. Genotyping of cases and controls was performed on a genome-wide SNP array to identify potential associated disease loci. The results from the genome-wide SNP array were then used to facilitate SNP selection and genotype validation was conducted using Sequenom-based genotyping. Results: Eleven of the 58 SNPs provided evidence of association with one of the phenotypes. For annular tears, rs1042631 SNP of AGC1 and rs467691 SNP of ADAMTS5 were highly significantly associated (p<.01) and SNPs in NGFB, IL1B, IL18RAP, and MMP10 were also significantly associated (p<.05). The rs4076018 SNP of NGFB was highly significant (p<.01) and rs2292657 SNP of GLI1 was significantly (p<.05) correlated to disc degeneration. For end-plate damage, the rs2252070 SNP of MMP 13 showed a significant association (p<.05). Previously associated genes such as COL 9, SKT, CHST 3, CILP, IGFR, SOXp, BMP, MMP 2-12, ADH2, IL1RN, and COX2 were not significantly associated and new associations (NGFB and GLI1) were identified. The validity of all the associations was found to be phenotype dependent. Conclusions: For the first time, genetic associations with DDD have been performed in an Indian population. Apart from identifying new associations, the highlight of the study was that in the same study population with DDD, SNP associations completely changed when different radiographic features were used to define the DDD phenotype. Our study results therefore indicate that standardization of the phenotypes chosen to study the genetics of disc degeneration is essential and should be strongly considered before planning genetic association studies. [Copyright &y& Elsevier]
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- 2013
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19. ISSLS Prize Winner: A Study of Effects of In Vivo Mechanical Forces on Human Lumbar Discs With Scoliotic Disc as a Biological Model.
- Author
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Rajasekaran, S., Vidyadhara, S., Subbiah, M., Kamath, Vijay, Karunanithi, R., Shetty, Ajoy Prasad, Venkateswaran, Krishna, Babu, Mary, and Meenakshi, J.
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PHYSIOLOGIC strain , *INTERVERTEBRAL disk diseases , *SCOLIOSIS , *LUMBAR vertebrae abnormalities , *DEGENERATION (Pathology) - Abstract
This article presents a study which investigates the effects of in vivo compressive and tensile mechanical forces on the lumbar discs with scoliotic disc as the biological model. It observes significant decrease in cell density and viability in all discs on both convex and concave sides compared to the control disc. It reveals changes in the endplate and nucleus pulposus even in discs with minimal wedging. It indicates nutritional factors as primary mechanism of degeneration induced by mechanical stress.
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- 2010
- Full Text
- View/download PDF
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