Browsing by Author "Jayakumar, K"

Now showing 1 - 12 of 12
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    A Shunt From the Brain: Left Internal Carotid Artery Arising From the Left Pulmonary Artery in Tetralogy of Fallot
    (ANNALS OF THORACIC SURGERY, 2015) Idhrees, AM; Mathew, T; Menon, S; Dharan, BS; Jayakumar, K
    Origin of a common carotid artery from a pulmonary artery is extremely rare, but isolated origin of an internal carotid artery from a pulmonary artery with intracardiac anomaly has not been reported before. We report a case of the left internal carotid artery arising from the left pulmonary artery in a case of tetralogy of Fallot. The possible embryologic mechanism and the surgical management of this unique lesion are described. (C) 2015 by The Society of Thoracic Surgeons
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    Constitution of FibrinBased Niche for In Vitro Differentiation of Adipose-Derived Mesenchymal Stem Cells to Keratinocytes
    (BioResearch Open Access, 2015-04) Unnikrishnan, S; Jayakumar, K; Krishnan, LK
    Epithelialization of chronic cutaneous wound is troublesome and may require use of skin/cell substitutes. Adipose- derived mesenchymal stem cells (ADMSCs) have immense potential as autologous cell source for treating wounds; they can cross the germ layer boundary of differentiation and regenerate skin. When multipotent adult stem cells are considered for skin regeneration, lineage committed keratinocytes may be beneficial to prevent undesirable post-transplantation outcome. This study hypothesized that ADMSCs may be directed to epidermal lineage in vitro on a specifically designed biomimetic and biodegradable niche. Cells were seeded on the test niche constituted with fibrin, fibronectin, gelatin, hyaluronic acid, laminin V, platelet growth factor, and epidermal growth factor in the presence of cell-specific differentiation medium (DM). The ADMSCs grown on bare tissue culture polystyrene surface in DM is designated DM-control and those grown in basal medium (BM) is the BM-control. Lineage commitment was monitored with keratinocyte-specific markers such as cytokeratin 14, cytokeratin 5, cytokeratin 19, and integrin a6 at the transcriptional/translational level. The in vitro designed biomimetic fibrin composite matrix may have potential application as cell transplantation vehicle.
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    Costing of homograft valve-Based on the experience from a homograft valve bank programme at a tertiary referral hospital in India
    (J Academy Hospital Administration., 2013-04) Jawahar, SK; Beena, B; Jayakumar, K; Antony, M
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    Differential response of human cardiac stem cells and bone marrow mesenchymal stem cells to hypoxia-reoxygenation injury
    (Molecular and Cellular Biochemistry, 2017-03) Deepthi, RS; Jayakumar, K; Nair, RR
    Cardiosphere-derived cells (CDCs) and bone marrow mesenchymal stem cells (MSCs) are popularly used in stem cell therapy for myocardial regeneration. The cell type that survives and maintains stem cell characteristics in the adverse microenvironment following ischemia–reperfusion injury is presumed to be ideal for transplantation. The study was therefore aimed at identifying the cell type with relatively greater resistance to ischemia–reperfusion injury. CDCs were isolated from the right atrial appendage and MSCs from bone marrow of patients who underwent coronary artery bypass graft surgery. Ischemia–reperfusion injury was simulated in vitro by subjecting the cells to hypoxia (0.5% O2) followed by reintroduction of oxygen (HR injury). Greater resistance of CDCs to HR injury was apparent from the decreased expression of senescence markers and lower proportion of apoptotic cells (one-sixth of that in MSCs). HR injury retarded cell cycle progression in MSCs. Consequent to HR injury, cell migration and secretion of stromal-derived growth factor were stimulated, significantly in CDCs. The differentiation to myocyte lineage and angiogenesis assessed by tube formation ability was better for CDCs. Release of vascular endothelial growth factor was relatively more in CDCs and was further stimulated by HR injury. Differentiation to osteogenic and angiogenic lineage was stimulated by HR injury in MSCs. Compared to MSCs, CDCs appear to be the cell of choice for promoting myocardial regeneration by virtue of its survival capacity in the event of ischemic insult along with higher proliferation rate, migration efficiency, release of growth factors with paracrine effects and differentiation to cardiac lineage.
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    Evaluation of intermediate term cardiac and neurodevelopmental outcomes of children undergoing corrective arterial switch operation for complete transposition of great arteries ( Project - 5367 )
    (SCTIMST, 2019-12-31) Arun, Gopalakrishnan; Sowmya, Ramanan; Soumya, Sundaram; Ajitkumar, VK; Jayakumar, K; Baiju S, Dharan
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    Intra-operative assessment of biventricular function using trans-esophageal echocardiography pre/post-pulmonary thromboembolectomy in patient with chronic thromboembolic pulmonary hypertension.
    (Annals of cardiac anaesthesia, 2009)
    Postoperative studies in patients with chronic thromboembolic pulmonary hypertension (CTPH) have shown that pulmonary thromboembolectomy (PTE) results in a rapid decrease of right ventricular (RV) size, improvement in the RV systolic function and left ventricular (LV) diastolic function. However, the extent to which the biventricular function recovers immediately after embolectomy in post-cardiopulmonary bypass period is not clear. A 45-year-old male patient was operated for retrieval of thrombus from pulmonary trunk and right pulmonary artery. Intraoperative transesophageal echocardiography (TOE) before surgery revealed signs of RV dysfunction and enlargement. The interventricular septum was seen moving paradoxically during end-systole and early-diastole. E/A ratio on transmitral Doppler flow velocity profile was about 0.63 and S/D ratio on pulmonary venous Doppler profile was 2.25, indicative of LV diastolic dysfunction. After weaning the patient from bypass, navigation on TOE showed marginal recovery of the RV systolic function and abatement of septal paradox to some extent. However, significant improvement was observed in the LV diastolic parameter (normal E/A ratio, S/D ratio of 1.08). We conclude that the geometrically altered LV recovers more than the hypertrophied and hypokinetic RV in a patient with CTPH in the post-bypass period.
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    Matrix-directed differentiation of human adipose derived mesenchymal stem cells to dermal-like fibroblasts that produce extracellular matrix
    (JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, 2015-04) Unnikrishnan, S; Jayakumar, K; Krishnan, LK
    Commercially available skin substitutes lack essential non-immune cells for adequate tissue regeneration of non-healing wounds. A tissue-engineered, patient-specific, dermal substitute could be an attractive option for regenerating chronic wounds, for which adipose-derived mesenchymal stem cells (ADMSCs) could become an autologous source. However, ADMSCs are multipotent in nature and may differentiate into adipocytes, osteocytes and chondrocytes in vitro, and may develop into undesirable tissues upon transplantation. Therefore, ADMSCs committed to the fibroblast lineage could be a better option for in vitro or in vivo skin tissue engineering. The objective of this study was to standardize in vitro culture conditions for ADMSCs differentiation into dermal-like fibroblasts which can synthesize extracellular matrix (ECM) proteins. Biomimetic matrix composite, deposited on tissue culture polystyrene (TCPS), and differentiationmedium(DM), supplemented with fibroblast-conditioned medium and growth factors,were used as a fibroblast-specific niche (FSN) for cell culture. For controls, ADMSCswere cultured on bare TCPS with either DM or basal medium (BM). Culture of ADMSCs on FSN upregulated the expression of differentiation markers such as fibroblast-specific protein-1 (FSP-1) and a panel of ECM molecules specific to the dermis, such as fibrillin-1, collagen I, collagen IV and elastin. Immunostaining showed the deposition of dermal-specific ECM,which was significantly higher in FSN compared to control. Fibroblasts derived from ADMSCs can synthesize elastin, which is an added advantage for successful skin tissue engineering as compared to fibroblasts fromskin biopsy. To obtain rapid differentiation of ADMSCs to dermal-like fibroblasts for regenerative medicine, a matrix-directed differentiation strategy may be employed. Copyright © 2014 John Wiley & Sons, Ltd
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    Matrix-directed differentiation of human adipose-derived mesenchymal stem cells to dermal-like fibroblasts that produce extracellular matrix
    (JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, 2016) Sivan, U; Jayakumar, K; Krishnan, LK
    Commercially available skin substitutes lack essential non-immune cells for adequate tissue regeneration of non-healing wounds. A tissue-engineered, patient-specific, dermal substitute could be an attractive option for regenerating chronic wounds, for which adipose-derived mesenchymal stem cells (ADMSCs) could become an autologous source. However, ADMSCs are multipotent in nature and may differentiate into adipocytes, osteocytes and chondrocytes in vitro, and may develop into undesirable tissues upon transplantation. Therefore, ADMSCs committed to the fibroblast lineage could be a better option for in vitro or in vivo skin tissue engineering. The objective of this study was to standardize in vitro culture conditions for ADMSCs differentiation into dermal-like fibroblasts which can synthesize extracellular matrix (ECM) proteins. Biomimetic matrix composite, deposited on tissue culture polystyrene (TCPS), and differentiationmedium(DM), supplemented with fibroblast-conditioned medium and growth factors, were used as a fibroblast-specific niche (FSN) for cell culture. For controls, ADMSCs were cultured on bare TCPS with either DM or basal medium (BM). Culture of ADMSCs on FSN upregulated the expression of differentiation markers such as fibroblast-specific protein-1 (FSP-1) and a panel of ECM molecules specific to the dermis, such as fibrillin-1, collagen I, collagen IV and elastin. Immunostaining showed the deposition of dermal-specific ECM, which was significantly higher in FSN compared to control. Fibroblasts derived from ADMSCs can synthesize elastin, which is an added advantage for successful skin tissue engineering as compared to fibroblasts fromskin biopsy. To obtain rapid differentiation of ADMSCs to dermal-like fibroblasts for regenerative medicine, a matrix-directed differentiation strategy may be employed. Copyright (C) 2014 John Wiley & Sons, Ltd.
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    Mitochondrial metabolism and function in type 2 diabetic heart ( Project - 5289 )
    (SCTIMST, 2018-06-17) Srinivas, G; Jayakumar, K; Vivek V, Pillai
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    Multiple Muscular Ventricular Septal Defects: Use of Fluorescein Dye to Identify Residual Defects
    (ANNALS OF THORACIC SURGERY, 2014) Mathew, T; Kundan, S; Abdulsamad, MI; Menon, S; Dharan, BS; Jayakumar, K
    Multiple muscular ventricular septal defects remain a challenge for the congenital heart surgeon. The optimal strategy for an infant or neonate with multiple muscular ventricular septal defects is still unclear. Perioperative identification and secure closure of these defects pose significant difficulties. We describe a novel technique of using fluorescein dye to identify small muscular ventricular septal defects. (C) 2014 by The Society of Thoracic Surgeons
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    Role of intraoperative echocardiography in surgical correction of the superior sinus venosus atrial septal defect.
    (Annals of cardiac anaesthesia, 2010)
    Superior type of sinus venosus atrial septal defect (SVASD) is invariably associated with the unroofing of right upper pulmonary vein (RUPV). Warden procedure and pericardial patch repair with rerouting of the RUPV are commonly performed operations for the superior SVASD. Both operations involve the risk of obstruction to the flow of superior vena cava or rerouted pulmonary vein in the postoperative period. The sinus venosus defects are well visualized on the transesophageal echocardiography (TEE) because of the proximity of the TEE probe to these structures. We are reporting two cases operated for the superior SVASD with unroofed RUPV, highlighting the intraoperative echocardiographic features before and after the surgery.
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    Successful repair of aortobronchial fistula using circulatory arrest
    (ANZ JOURNAL OF SURGERY, 2007) Bhuyan, RR; Rajendran, S; Unnikrishnan, M; Jayakumar, K