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Thakar S, Raj V, Neelakantan S, Vasoya P, Aryan S, Mohan D, Hegde AS. Spinal Morphometry As A Novel Predictor For Recurrent Lumbar Disc Herniation Requiring Revision Surgery: Results of A Case Control Study. Neurol India 2022; 70:S211-S217. [PMID: 36412371 DOI: 10.4103/0028-3886.360932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Introduction There is conflicting data on the risk factors for recurrent lumbar disc herniation (rLDH). Most of the predictors for rLDH identified so far are acquired risk factors or radiological factors at the level of the herniation. Whole lumbar spine (WLS) morphometry has not been evaluated as a possible predictor of rLDH. Objectives We aimed to evaluate if preoperative spinal morphometry can predict the occurrence of rLDH requiring revision surgery. Methods This retrospective case-control study on 250 patients included 45 patients operated for rLDH, 180 controls without rLDH who had previously undergone microdiscectomy for a single level lumbar disc prolapse, and a holdout validation set of 25 patients. Morphometric variables related to the WLS were recorded in addition to previously identified predictors of rLDH. Logistic regression (LR) analysis was performed to identify independent predictors of rLDH. Results LR yielded four predictors of which two were WLS morphometric variables. While increasing age and smoking positively predicted rLDH, increasing WLS interfacet distance and WLS dural-sac circumference negatively predicted rLDH. The LR model was statistically significant, χ2 (4) =15.98, P = 0.003, and correctly classified 80.3% of cases. On validation, the model demonstrated a fair accuracy in predicting rLDH (accuracy: 0.80, AUC: 0.70). Conclusions Larger mean lumbar bony canals and dural sacs protect from the occurrence of symptomatic rLDH. These WLS morphometric variables should be included in future risk stratification algorithms for lumbar disc disease. In addition to the previously recognized risk factors, our study points to an underlying developmental predisposition for rLDH.
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Affiliation(s)
- Sumit Thakar
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Vivek Raj
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Sankar Neelakantan
- Department of Radiodiagnosis, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Pavan Vasoya
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Saritha Aryan
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Dilip Mohan
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Alangar S Hegde
- Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
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Neelakantan S, Kumaran SP, Viswamitra S, Ghosal N. Myriad of MR imaging phenotypes of primary central nervous system lymphoma in a cohort of immunocompetent Indian patient population. Indian J Radiol Imaging 2021; 28:296-304. [PMID: 30319205 PMCID: PMC6176660 DOI: 10.4103/ijri.ijri_23_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PCNSL (primary central nervous system lymphoma) is a chemosensitive and radiosensitive tumor, and early diagnosis has a significant impact on management. Unlike many other brain tumors, radical surgical excision of PCNSLs is not indicated because these lesions are highly infiltrative and even partial resection leads to a bad prognosis. The goal of this study is to highlight the unusual radiological presentation of PCNSLs and increase the awareness, familiarity, and global database of our observations that pose a challenge on management.
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Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bengaluru, Karnataka, India
| | - Sunitha P Kumaran
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bengaluru, Karnataka, India
| | - Sanjaya Viswamitra
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bengaluru, Karnataka, India
| | - Nandita Ghosal
- Department of Pathology, Sri Sathya Sai Institute of Higher Medical Sciences, Bengaluru, Karnataka, India
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3
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Kumaran SP, Thippeswamy PB, Reddy BN, Neelakantan S, Viswamitra S. An Institutional Review of Tuberculosis Spine Mimics on MR Imaging: Cases of Mistaken Identity. Neurol India 2020; 67:1408-1418. [PMID: 31857525 DOI: 10.4103/0028-3886.273630] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Although MRI has a spectrum of findings which help in the diagnosis of tuberculosis (TB) spine, a broad spectrum of spine pathologies resemble Pott's spine on MRI and are often missed due to inadequate clinical details. As a result, patients are often subject to unnecessary biopsy. A blinded radiologist may misdiagnose such mimic cases as TB. Our aim is to enable the reader to learn the main criteria that differentiate spine TB from other spine etiologies that mimic TB. A retrospective search was done and authors collected only MRI spine reports that showed a differential diagnosis or diagnosis of TB spine from the computer-based data records of the institution over a four-year period. This revealed 306 cases of TB spine out of which 78 cases with an alternate diagnosis that resembled TB spine were included. We describe a single institute review of 78 such cases that resemble and mimic Pott's spine on MRI. The cases being: (n = 15) pyogenic spondylitis, (n = 1) brucellar spondylodiscitis, (n = 12) rheumatoid arthritis, (n = 12) metastases, (n = 8) lymphoma, (n = 5) post-trauma fractures, (n = 10) degenerative disc disease, (n = 2) Baastrup's disease, (n = 9) osteoporotic fracture, (n = 3) spinal neuropathic arthritis, and (n = 1) case of Rosai-Dorfman disease. The clinical and radiological findings of all these cases were correlated with lab findings and histopathology wherever necessary. Appropriate recognition of these entities that resemble and mimic TB spine on MRI is important for optimal patient care. This paper exposes radiologists to a variety of spine pathologies for which biopsy is not indicated, and highlights key imaging findings of these entities to facilitate greater diagnostic accuracy in clinical practice.
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Affiliation(s)
- Sunitha Palasamudram Kumaran
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru, Karnataka, India
| | | | - Bhavana Nagabhushan Reddy
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru, Karnataka, India
| | | | - Sanjaya Viswamitra
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bengaluru, Karnataka, India
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Samireddypalle Y, V. UMR, Deepak C, Neelakantan S, KS AV. A Case of Needle-Directed Pulse-Spray Pharmacomechanical Thrombolysis of Acute Brachial Artery Thrombosis. J Clin Interv Radiol ISVIR 2019. [DOI: 10.1055/s-0039-3401326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
AbstractAcute limb ischemia is a serious disabling condition. The management options depend upon the patient symptoms and signs of ischemia in the affected limb. The management options include surgical thrombo-embolectomy and catheter directed thrombolysis. Catheter directed thrombolysis has now become the first line of management in symptomatic cases. Here, we discuss a case of acute left brachial artery thrombosis which was successfully managed by needle-directed pulse-spray thrombolysis.
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Affiliation(s)
| | - Uma Maheshwara Reddy V.
- Department of Radiology, Narayana Medical College and Hospital, Nellore, Andhra Pradesh, India
| | - Chinmay Deepak
- Department of Radiology, Manipal Hospitals, Bangalore, Karnataka, India
| | - Sankar Neelakantan
- Department of Radiology, Sakra World Hospital, Bangalore, Karnataka, India
| | - Amitha Vikrama KS
- Department of Radiology, Sakra World Hospital, Bangalore, Karnataka, India
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Neelakantan S, Samant R, Prasad J, Reddy B, Reddy P, Das B, Viswamitra S, Mohan D. Digital Subtraction Neuroangiography: What a Resident Should Know. J Clin Interv Radiol ISVIR 2019. [DOI: 10.1055/s-0039-1681979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
AbstractNeuroangiography (NA) is an integral investigation in the management of patients with neurovascular diseases. NA is basically used for diagnosis, but in many instances, it may be followed up with treatment in the same sitting. Indications for diagnostic NA range from extracranial diseases (vertebra-basilar insufficiency from subclavian steal, extracranial carotid stenosis, cavernous-carotid fistula, neck trauma, epistaxis, etc.) to intracranial diseases (nontraumatic subarachnoid hemorrhage, cerebral aneurysms, cerebral arteriovenous malformations, cerebral vasospasm, acute stroke, etc.). A sound understanding of the principles of appropriate periprocedural care and anatomy, catheter technique, and basic disease pathology are vital for the test to be diagnostic. This pictorial review illustrates normal neurovascular anatomy along with an approach to analyze a spectrum of neurovascular pathologies and also explains a step-wise checklist for appropriate preprocedural assessment, technique of procedure, and postprocedural care of the patient. Basic knowledge on how to interpret these images and principles on how to perform it is important.
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Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Rohan Samant
- Department of Radiology, UAMS, Arkansas, Texas, United States
| | - Jagadish Prasad
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Bhavana Reddy
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Prashanth Reddy
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Bharath Das
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Sanjaya Viswamitra
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
| | - Dilip Mohan
- Department of Neruosurgery, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore, Karnataka, India
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Samireddypalle Y, S. A, Neelakantan S. Endovascular Management of Massive Hematemesis due to Aorto-Esophageal Fistula. J Clin Interv Radiol ISVIR 2019. [DOI: 10.1055/s-0039-1681120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
| | - Amitha S.
- Department of Interventional Radiology, Sakra World Hospital, Bangalore, Karnataka, India
| | - Sankar Neelakantan
- Department of Interventional Radiology, Sakra World Hospital, Bangalore, Karnataka, India
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Neelakantan S, Anandarajan R, Shyam K, Philip B. Multimodality imaging in Bertolotti's syndrome: an important cause of low back pain in young adults. BMJ Case Rep 2016; 2016:bcr-2016-217121. [PMID: 27873760 DOI: 10.1136/bcr-2016-217121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, St. Johns medical college and hospital, Bangalore, Karnataka, India
| | - Rakesh Anandarajan
- Department of Radiology, St. Johns medical college and hospital, Bangalore, Karnataka, India
| | - Karthik Shyam
- Department of Radiology, St. Johns medical college and hospital, Bangalore, Karnataka, India
| | - Babu Philip
- Department of Radiology, St. Johns medical college and hospital, Bangalore, Karnataka, India
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8
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Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, St Johns Medical College and Hospital, Bangalore, Karnataka, India
| | - Rakesh Anandarajan
- Department of Radiology, St Johns Medical College and Hospital, Bangalore, Karnataka, India
| | - Anil Kumar Swamy
- Department of Radiology, St Johns Medical College and Hospital, Bangalore, Karnataka, India
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9
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Neelakantan S, Babu AAS, Anandarajan R. 'Dot in circle sign': a characteristic finding in ultrasound and MR imaging of soft tissue mycetomas. BMJ Case Rep 2016; 2016:bcr-2016-216502. [PMID: 27702932 PMCID: PMC5073639 DOI: 10.1136/bcr-2016-216502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, HealthCare Global Enterprises Ltd, Bangalore, Karnataka, India
| | | | - Rakesh Anandarajan
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
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10
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Neelakantan S, Babu AAS, Anandarajan R, Philip B. Hepatic hydatid disease presenting as secondary Budd-Chiari syndrome. BMJ Case Rep 2016; 2016:bcr-2016-217118. [PMID: 27681355 PMCID: PMC5051358 DOI: 10.1136/bcr-2016-217118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, HealthCare Global Enterprises, Bangalore, Karnataka, India
| | | | - Rakesh Anandarajan
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Babu Philip
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
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Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, St. Johns Medical College and Hospital, Bangalore, Karnataka, India
| | - Ravikanth Reddy
- Department of Radiology, St. Johns Medical College and Hospital, Bangalore, Karnataka, India
| | - Anil Kumar Swamy
- Department of Radiology, St. Johns Medical College and Hospital, Bangalore, Karnataka, India
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12
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Affiliation(s)
- Asthik Biswas
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | | | - Sankar Neelakantan
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Partha Sarathi Sarkar
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
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14
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Neelakantan S, Jose W, Cicilet S, Biswas A. Multimodality imaging of a paediatric pancreatic fracture. BMJ Case Rep 2016; 2016:bcr-2016-215708. [PMID: 27194677 DOI: 10.1136/bcr-2016-215708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Sankar Neelakantan
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Warun Jose
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Soumya Cicilet
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Asthik Biswas
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
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15
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Biswas A, Furruqh F, Thirunavukarasu S, Neelakantan S. Benign enlargement of subarachnoid spaces: a cause of subdural haemorrhage in toddlers. BMJ Case Rep 2016; 2016:bcr-2016-215753. [PMID: 27143167 DOI: 10.1136/bcr-2016-215753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Asthik Biswas
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Farha Furruqh
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
| | - Suresh Thirunavukarasu
- Department of Neurology, Indira Gandhi Government General Hospital and Post Graduate Institute, Puducherry, Puducherry, India
| | - Sankar Neelakantan
- Department of Radiology, St Johns Medical College Hospital, Bangalore, Karnataka, India
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Young G, Mahlangu J, Kulkarni R, Nolan B, Liesner R, Pasi J, Barnes C, Neelakantan S, Gambino G, Cristiano LM, Pierce GF, Allen G. Recombinant factor VIII Fc fusion protein for the prevention and treatment of bleeding in children with severe hemophilia A. J Thromb Haemost 2015; 13:967-77. [PMID: 25912075 DOI: 10.1111/jth.12911] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/16/2015] [Indexed: 08/31/2023]
Abstract
BACKGROUND Prophylactic factor replacement, which prevents hemarthroses and thereby reduces the musculoskeletal disease burden in children with hemophilia A, requires frequent intravenous infusions (three to four times weekly). OBJECTIVE Kids A-LONG was a phase 3 open-label study evaluating the safety, efficacy and pharmacokinetics of a longer-acting factor, recombinant factor VIII Fc fusion protein (rFVIIIFc), in previously treated children with severe hemophilia A (endogenous FVIII level of < 1 IU dL(-1) [< 1%]). METHODS The study enrolled 71 subjects. The starting rFVIIIFc regimen was twice-weekly prophylaxis (Day 1, 25 IU kg(-1) ; Day 4, 50 IU kg(-1) ); dose (≤ 80 IU kg(-1) ) and dosing interval (≥ 2 days) were adjusted as needed. A subset of subjects had sequential pharmacokinetic evaluations of FVIII and rFVIIIFc. The primary endpoint was development of inhibitors (neutralizing antibodies). Secondary endpoints included pharmacokinetics, annualized bleeding rate (ABR), and number of infusions required to control a bleed. RESULTS No subject developed an inhibitor to rFVIIIFc. Adverse events were typical of a pediatric hemophilic population. The rFVIIIFc half-life was prolonged relative to that of FVIII, consistent with observations in adults and adolescents. The median ABR was 1.96 overall, and 0.00 for spontaneous bleeds; 46.4% of subjects reported no bleeding episodes on study. Ninety-three per cent of bleeding episodes were controlled with one to two infusions. The median average weekly rFVIIIFc prophylactic dose was 88.11 IU kg(-1) . At study end, 62 of 69 subjects (90%) were infusing twice weekly. Among subjects who had been previously receiving FVIII prophylaxis, 74% reduced their dosing frequency with rFVIIIFc. CONCLUSION Twice-weekly infusions with rFVIIIFc were well tolerated and yielded low bleeding rates in children with severe hemophilia A.
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Affiliation(s)
- G Young
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - J Mahlangu
- University of the Witwatersrand Faculty of Health Sciences, Johannesburg, South Africa
| | - R Kulkarni
- Michigan State University, East Lansing, MI, USA
| | - B Nolan
- Our Lady's Children's Hospital, Dublin, Ireland
| | - R Liesner
- Great Ormond Street Hospital for Children, London, UK
| | - J Pasi
- Barts and the London Comprehensive Care Centre, London, UK
| | - C Barnes
- Royal Children's Hospital, Melbourne, Victoria, Australia
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Shapiro AD, Ragni MV, Kulkarni R, Oldenberg J, Srivastava A, Quon DV, Pasi KJ, Hanabusa H, Pabinger I, Mahlangu J, Fogarty P, Lillicrap D, Kulke S, Potts J, Neelakantan S, Nestorov I, Li S, Dumont JA, Jiang H, Brennan A, Pierce GF. Recombinant factor VIII Fc fusion protein: extended-interval dosing maintains low bleeding rates and correlates with von Willebrand factor levels. J Thromb Haemost 2014; 12:1788-800. [PMID: 25196897 DOI: 10.1111/jth.12723] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/01/2014] [Indexed: 08/31/2023]
Abstract
BACKGROUND Routine prophylaxis with replacement factor VIII (FVIII) - the standard of care for severe hemophilia A - often requires frequent intravenous infusions (three or four times weekly). An FVIII molecule with an extended half-life could reduce infusion frequency. The A-LONG study established the safety, efficacy and prolonged pharmacokinetics of recombinant FVIII Fc fusion protein (rFVIIIFc) in previously treated adolescents and adults with severe hemophilia A. OBJECTIVE In this post hoc analysis, we investigated the relationship between subjects' prestudy (FVIII) and on-study (rFVIIIFc) regimens. METHODS We analyzed two subgroups of subjects: prior prophylaxis and on-study individualized prophylaxis (n = 80), and prior episodic treatment and on-study weekly prophylaxis (n = 16). Subjects' prestudy dosing regimens and bleeding rates were compared with their final rFVIIIFc regimens and annualized bleeding rates (ABRs) in the last 3 months on-study. Dosing regimen simulations based on population pharmacokinetics models for rFVIII and rFVIIIFc were performed. RESULTS As compared with their prestudy regimen, 79 of 80 (98.8%) subjects on individualized rFVIIIFc prophylaxis decreased their infusion frequency. Overall ABRs were low, with comparable factor consumption. Longer dosing intervals, including 5-day dosing, were associated with higher baseline von Willebrand factor antigen levels. Simulated dosing regimens predicted a greater proportion of subjects with steady-state FVIII activity trough levels of ≥ 1 IU dL(-1) (1%) with rFVIIIFc than with equivalent rFVIII regimens. CONCLUSION These results suggest that patients on rFVIIIFc prophylaxis can reduce their infusion frequency as compared with their prior FVIII regimen while maintaining low bleeding rates, affording more patients trough levels of ≥ 1 IU dL(-1) than with rFVIII products requiring more frequent dosing regimens.
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Affiliation(s)
- A D Shapiro
- Department of Hematology, Indiana Hemophilia and Thrombosis Center, Indianapolis, IN, USA
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18
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Garg SK, Neelakantan S. Effect of nutritional factors on cellulase enzyme and microbial protein production by Aspergillus terreus and its evaluation. Biotechnol Bioeng 2009; 24:109-25. [PMID: 18546104 DOI: 10.1002/bit.260240110] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The biomass yield, cellulolytic activity, and protein recovery using Aspergillus terreus GN1 with alkali-treated sugarcane bagasse was studied using different levels (250-600 mg of N/L of broth) of organic and inorganic nitrogen sources. e.g., cattle urine, urea, cornsteep liquor, ammonium sulfate, ammonium nitrate, ammonium iron sulfate, ammonium chloride, and sodium nitrate. Among different levels of alkali-treated bagasse substrate concentrations (0.5-4.0% w/v) tested, 1.0% substrate yielded the highest crude protein content, protein recovery, and cellulolytic activity. The biomass recovery with 1.0% substrate ranged from 290-380 mg/500 mg bagasse substrate in a 50-mL broth with a nitrogen level of 250-600 mg of N/L in all the sources except ammonium iron sulfate, which yielded 402-439 mg/500 mg bagasse substrate. However, crude protein content of biomass obtained with an ammonium iron sulfate nitrogen source was the lowest. Cornsteep liquor nitrogen source at the rate of 600 mg of N/L yielded the maximum crude protein of 32.9%, protein recovery of 22.2 g/100 g of bagasse, and carboxymethyl cellulase and filter paper enzyme activities of 1.1 and 0.09 units/mL, among the organic and inorganic nitrogen sources studied. In general, the organic nitrogen sources and inorganic nonammonium nitrogen sources were utilized preferentially for protein production over the inorganic ammonium nitrogen sources. The fermentation time required under optimum cultural and nutritional conditions for A. terreus GN1 was also evaluated. The crude protein content of the biomass increased gradually up to the seventh day of fermentation, but the protein recovery rate was high up to two or three days. It was observed that the cellulose utilization rate increased after an initial lag of one day up to the third day and gradually increased further, which corresponded positively with protein content, biomass protein recovery, and cellulase enzyme activity. On the seventh day of fermentation, the crude protein content, biomass protein recovery, water-soluble carbohydrate, bagasse cellulose utilization, CMCase, and FPase activities were 32.8%, 20.1 g/100 g of bagasse, 6.2%, 82.7%, 1.0. and 0.08 U/mL, respectively. The final biomass recovered contained 32.8% crude protein content and had an in vitro rumen digestibility (IVRD) coefficient of 68.8%. The biomass contained almost all the essential and nonessential amino acids and was comparable with FAO reference protein. It is concluded that a fermentation time of 72 h gave a faster rate of protein production of 16.9 g/100 g of bagasse with 69.8% bagasse cellulose utilization with 76.0% IVRD. and contained almost all the essential and nonessential amino acids.
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Affiliation(s)
- S K Garg
- Dairy Microbiology Division, National Dairy Research Institute, Karnal 132001, India
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19
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Abstract
A 'bottom-up' PK/PD analysis approach employing system analysis principles of convolution/deconvolution and special nonparametric estimation procedures is presented to resolve the complex 'endo-PK/PD' of the endogenous form of recombinant drugs using erythropoietin (EPO) as an example. A novel cellular deconvolution algorithm is presented that facilitates the identification of the functional relationship between the variables involved in EPO's complex PK/PD. Five sheep each underwent two phlebotomies spaced 4-6 weeks apart when their hemoglobin levels were reduced from 12 g/dl to 3-4 g/dl. EPO levels and reticulocyte counts were frequently sampled. The data were analysed using end-constrained cubic splines. The rate of reticulocyte production was determined using the novel deconvolution methodology. The erythroid progenitor cells activation rate by EPO was estimated from the reticulocyte production rate using a lag-time parameter which determines the delay in the reticulocyte appearance in the blood relative to the activation of erythroid progenitors. Hysteresis minimization combined with cellular deconvolution was employed to determine the population PK/PD transduction function relating the progenitor activation rate to EPO concentrations in a nonparametric manner without assuming a specific structure. The proposed approach provides a rational informative starting point for developing parametric PK/PD models to resolve the complex endo-PK/PD of recombinant drugs.
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Affiliation(s)
- S. Neelakantan
- College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA
| | - J.A. Widness
- Department of Pediatrics, College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - R.L. Schmidt
- Department of Pediatrics, College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - P. Veng-Pedersen
- College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA
- Correspondence to: College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA.
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Neelakantan S, Veng-Pedersen P. Determination of drug absorption rate in time-variant disposition by direct deconvolution using beta clearance correction and end-constrained non-parametric regression. Biopharm Drug Dispos 2005; 26:353-70. [PMID: 16088968 DOI: 10.1002/bdd.468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A novel numerical deconvolution method is presented that enables the estimation of drug absorption rates under time-variant disposition conditions. The method involves two components. (1) A disposition decomposition-recomposition (DDR) enabling exact changes in the unit impulse response (UIR) to be constructed based on centrally based clearance changes iteratively determined. (2) A non-parametric, end-constrained cubic spline (ECS) input response function estimated by cross-validation. The proposed DDR-ECS method compensates for disposition changes between the test and the reference administrations by using a "beta" clearance correction based on DDR analysis. The representation of the input response by the ECS method takes into consideration the complex absorption process and also ensures physiologically realistic approximations of the response. The stability of the new method to noisy data was evaluated by comprehensive simulations that considered different UIRs, various input functions, clearance changes and a novel scaling of the input function that includes the "flip-flop" absorption phenomena. The simulated input response was also analysed by two other methods and all three methods were compared for their relative performances. The DDR-ECS method provides better estimation of the input profile under significant clearance changes but tends to overestimate the input when there were only small changes in the clearance.
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Affiliation(s)
- S Neelakantan
- College of Pharmacy, The University of Iowa, Iowa City, IA 52242, USA
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Abstract
Six of the 2100 colonies of lactic acid bacteria isolated from 4 month old Cheddar cheese and raw buffalo milk showed antifungal activity against Aspergillus flavus IARI when tested by the well agar diffusion assay on Potato Dextrose Agar containing 0.1% Triton X-100. Out of these, the most promising isolate having a broad spectrum of antifungal activity including Aspergillus flavus IARI, A. flavus NCIM 555, A. parasiticus NCIM 898 and Fusarium spp. was identified as Lactococcus lactis subsp. lactis CHD-28.3. Among the mold cultures used as indicator strains, the most sensitive towards antifungal substance produced by the test culture was A. flavus IARI. The cell-free supernatant of the test culture in Elliker's broth adjusted to pH 6.8 produced an inhibition zone of 15-19 mm against A. flavus IARI, A. flavus NCIM555 and A. parasiticus NCIM898. The isolate when grown at 30 degrees C for 48 h in Elliker's broth showed optimum antifungal activity. When the supernatant was neutralized to pH 7.0 or 7.5, there was little reduction in activity. However, after enzymatic treatment of supernatant with chymotrypsin, trypsin and pronase E, the antifungal activity disappeared which indicated the proteinaceous nature of the antifungal substance.
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Affiliation(s)
- U Roy
- Molecular Biology Unit, National Dairy Research Institute, Haryana, India
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Garg SK, Neelakantan S. Effect of Different Nitrogen Sources and Cultural Conditions on Fermentation of Bagasse byAspergillus terreus. Journal of Applied Animal Research 1992. [DOI: 10.1080/09712119.1992.9705905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Neelakantan S, Mishra MM, Bhardwaj SK, Vyas SR. Qualitative microbiological changes during decomposition of plant material in a sandy sierozem soil. Folia Microbiol (Praha) 1974; 19:55-8. [PMID: 4430478 DOI: 10.1007/bf02874503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Neelakantan S, Padmasani R, Seshadri T. Synthesis of atranorin. Tetrahedron Lett 1962. [DOI: 10.1016/s0040-4039(00)70868-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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