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Ramkumar S, Ranjbar S, Ning S, Lal D, Zwart CM, Wood CP, Weindling SM, Wu T, Mitchell JR, Li J, Hoxworth JM. MRI-Based Texture Analysis to Differentiate Sinonasal Squamous Cell Carcinoma from Inverted Papilloma. AJNR Am J Neuroradiol 2017; 38:1019-1025. [PMID: 28255033 DOI: 10.3174/ajnr.a5106] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/13/2016] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND PURPOSE Because sinonasal inverted papilloma can harbor squamous cell carcinoma, differentiating these tumors is relevant. The objectives of this study were to determine whether MR imaging-based texture analysis can accurately classify cases of noncoexistent squamous cell carcinoma and inverted papilloma and to compare this classification performance with neuroradiologists' review. MATERIALS AND METHODS Adult patients who had inverted papilloma or squamous cell carcinoma resected were eligible (coexistent inverted papilloma and squamous cell carcinoma were excluded). Inclusion required tumor size of >1.5 cm and preoperative MR imaging with axial T1, axial T2, and axial T1 postcontrast sequences. Five well-established texture analysis algorithms were applied to an ROI from the largest tumor cross-section. For a training dataset, machine-learning algorithms were used to identify the most accurate model, and performance was also evaluated in a validation dataset. On the basis of 3 separate blinded reviews of the ROI, isolated tumor, and entire images, 2 neuroradiologists predicted tumor type in consensus. RESULTS The inverted papilloma (n = 24) and squamous cell carcinoma (n = 22) cohorts were matched for age and sex, while squamous cell carcinoma tumor volume was larger (P = .001). The best classification model achieved similar accuracies for training (17 squamous cell carcinomas, 16 inverted papillomas) and validation (7 squamous cell carcinomas, 6 inverted papillomas) datasets of 90.9% and 84.6%, respectively (P = .537). For the combined training and validation cohorts, the machine-learning accuracy (89.1%) was better than that of the neuroradiologists' ROI review (56.5%, P = .0004) but not significantly different from the neuroradiologists' review of the tumors (73.9%, P = .060) or entire images (87.0%, P = .748). CONCLUSIONS MR imaging-based texture analysis has the potential to differentiate squamous cell carcinoma from inverted papilloma and may, in the future, provide incremental information to the neuroradiologist.
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Ramkumar S, Narayanasamy N. Collaboration and networking in research grant projects in speech, language and hearing sciences. COLLNET JOURNAL OF SCIENTOMETRICS AND INFORMATION MANAGEMENT 2017. [DOI: 10.1080/09737766.2016.1251558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ramkumar S, Yang H, Wang Y, Jansen HY, Nolan M, Marwick T, Negishi K. Is the Calibration Method for Central Blood Pressure Important in Assessing the Association Between Central Blood Pressure with LV and Left Atrial Strain? Heart Lung Circ 2017. [DOI: 10.1016/j.hlc.2017.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ramkumar S, Yang H, Wang Y, D’Elia N, Ochi A, West H, Nolan M, Negishi K, Marwick T. Left Atrial and Left Ventricular Strain in the Prediction of Atrial Fibrillation in a Community Cohort with Risk Factors. Heart Lung Circ 2017. [DOI: 10.1016/j.hlc.2017.06.511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ganesh A, Ramkumar S, Rajkumar M, Bhavyaa R, Ramkumar L, Balaji SK. Oral health-related knowledge, attitude, and practices among auto drivers in South Chennai. JOURNAL OF INDIAN ASSOCIATION OF PUBLIC HEALTH DENTISTRY 2017. [DOI: 10.4103/jiaphd.jiaphd_97_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Ramkumar S, Yang H, Wang Y, Nolan M, Negishi K, Marwick T. Prediction of Heart Failure and Atrial Fibrillation Using the CHARGE-AF and ARIC Risk Scores. Heart Lung Circ 2017. [DOI: 10.1016/j.hlc.2017.06.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ramkumar S, Vijayalakshmi S, Seetharaman N, Pajanivel R, Lokeshmaran A. Health-related quality of life among tuberculosis patients under Revised National Tuberculosis Control Programme in rural and urban Puducherry. Indian J Tuberc 2016; 64:14-19. [PMID: 28166911 DOI: 10.1016/j.ijtb.2016.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 08/25/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Globally, tuberculosis (TB) continues to be the major public health problem. Limited research is carried out on the impact of the disease on health-related quality of life (HR-QoL). The study aims to assess the HR-QoL among TB patients during and after Directly Observed Treatment Short-course (DOTS) therapy and to compare the HR-QoL of these patients with matched neighbourhood controls. METHODOLOGY A community-based longitudinal study was conducted in Ariyankuppam and Bahour communes of Puducherry from January 2014 to April 2015. 92 TB patients registered for DOTS therapy during January-June 2014 were interviewed in their DOTS centres during first visit using the SF-36 questionnaire to assess their HR-QoL. During the second visit, 9 TB patients were lost to follow-up; therefore, a total of 83 patients were interviewed in their houses and, simultaneously, 83 matched neighbourhood controls were interviewed. Non-parametric tests were used to compare the HR-QoL scores. p value <0.05 was considered as statistically significant. RESULTS The mean HR-QoL scores had improved among TB patients upon completion of DOTS (80.8±20.3), when compared to HR-QoL scores (48.3±30) during treatment with significant difference. The HR-QoL scores of TB patients after DOTS completion (80.8±20.3) had improved to levels comparable to that of non-TB controls (77.5±29.1) without significant difference. CONCLUSION HR-QoL of patients suffering from TB was low. However, the study provides evidence that DOTS treatment offers a demonstrable improvement of HR-QoL among TB patients almost to the level of general population. The findings can be used in advocating the effectiveness of DOTS in TB control efforts.
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Ramkumar S, Rashid H, Zaman S, McCormick L, Gooley R, Jackson D, Meredith I. Comparison of Outcomes Between Nonagenarians and Younger Patients Undergoing Transcatheter Aortic Valve Replacement (TAVR) with the LOTUS Valve. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rashid H, McCormick L, Gooley R, Ramkumar S, Meredith I. Simultaneous Transcatheter Aortic Valve Implantation and Drive-By Endovascular Aortic Aneurysm Repair with the Lotus Valve System. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Rashid H, Ramkumar S, Haji K, Nerlekar N, Mottram P, Moir S. Determining the Aortic Root Geometry of Congenital Bicuspid Aortic Valves Through 320-Slice Multidetector CT and its Implications for Transcatheter Aortic Valve Replacement. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ramkumar S, Yang H, Wang Y, Nolan M, Negishi K, Marwick T. Reduced Functional Capacity: An Independent Risk Predictor of Atrial Fibrillation. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Ramkumar S, Yang H, Wang Y, Nolan M, Negishi K, Marwick T. Left Ventricular Mechanics as an Independent Risk Predictor of Atrial Fibrillation. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ramkumar S, Yang H, Wang Y, Nolan M, Negishi K, Marwick T. Comparing the Prediction of Heart Failure Symptoms Using a Clinical Score Assessing Risk of Atrial Fibrillation (CHARGE-AF) to Traditional Heart Failure Risk Scores. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Nerlekar N, Cheng K, Ramkumar S, Rehmani H, Vasanthakumar S, Rashid H, Talman A, Muthalaly R, Barton T, Nasis A, Moir S, Meredith I, Mottram P. Prognostic Value of Exercise Stress Echocardiography in Potential Renal Transplant Recipients. Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ramkumar S, Rashid H, Zaman S, McCormick L, Gooley R, Jackson D, Meredith I. Does Pulmonary Hypertension Prior to Transcatheter Aortic Valve Replacement (TAVR) With the Lotus Valve Predict Poor Clinical Outcomes? Heart Lung Circ 2016. [DOI: 10.1016/j.hlc.2016.06.404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ramkumar S, Rao S, Waldie K. Dairy Cattle Rearing by Landless Rural Women in Pondicherry: A Path to Empowerment. INDIAN JOURNAL OF GENDER STUDIES 2016. [DOI: 10.1177/097152150401100204] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rearing one or two cows for milk is an important source of livelihood for landless women in Pondicherry in south Indin.1 Possession of dairy animals means more than increased income for them: it means financial security, status, self-confidence and an opportunity to liave some control over their lives. Preferring this alternative to exhnusting agricultural labour, the women are self-employed, with flexible work ing hours and maintain better health as a result. Recognition of the importance of this resource for rural women should be the first step towards improving service delivery to poor landless women rearing dairy cattle.
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Rao SVN, Rasheed Sulaiman V, Natchimuthu K, Ramkumar S, Sasidhar PVK. Improving the delivery of veterinary services in India. REV SCI TECH OIE 2016; 34:767-77. [PMID: 27044150 DOI: 10.20506/rst.34.3.2394] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In pursuit of effective veterinary service delivery, the objectives of this study were threefold: (i) reduce the shortage of technical personnel in veterinary universities (VUs) and animal husbandry departments (AHDs), (ii) identify collaborative areas between VUs and AHDs, and (iii) build the capacity of the veterinary and animal husbandry sector. Primary data were collected from all the 16 veterinary colleges and AHDs in five south Indian states on: (i) student intake and the out-turn of veterinary graduates, (ii) technical personnel--existing and required at various levels, (iii) specific areas of collaboration where VUs and AHDs need each other and can extend support to each other, and (iv) areas in which university faculty and field veterinarians would benefit from further training. Two focus group discussions were held with top administrators of VUs and AHDs to collect qualitative data. The results revealed that there are not enough veterinary graduates to meet the needs of the system and that there is a shortage of faculty, field veterinarians and para-veterinarians. Both focus groups identified areas for collaboration and capacity building to improve veterinary service delivery. The results conclusively demonstrated that India's veterinary service delivery is constrained, not due to a lack of organisations or programmes, but due to the inability of the organisations to collaborate with each other. To improve the effectiveness of veterinary service delivery it will be necessary to: admit more graduate students, support the establishment of new colleges; recruit faculty, field veterinarians and para-veterinarians; remandate the Directorates of Extension at VUs to develop linkages with AHDs; allocate funds ('special central grants') for infrastructure development to all AHDs and veterinary colleges; establish one model veterinary college that follows international standards on veterinary education and create four regional academic staff training colleges exclusively for the purpose of developing the capacity of the veterinary and animal husbandry sector. Action plans to implement these recommendations are also suggested.
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Vijayaraju D, Prakash G, Yoganandh T, Subramanian SR, Ramkumar S. Salt and Pepper Pigmentation - Skin Manifestation of Systemic Sclerosis. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2015; 63:70. [PMID: 27608870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A 50 year old male presented with progressive difficulty in swallowing both liquid and solid food with no history of Raynaud's phenomenon. A general examination revealed skin changes in the form of thickening, hyperpigmentation and tightening of skin of fingers, hand, forearm and legs. The patient had painless skin induration over the legs, forearm and hand. Salt and pepper pigmentation was seen on the upper back (Figure 1a), over mastoid process (Figure 1b) and the concha of pinna (Figure 1c). Anti-Scl 70 was positive. Anti-centromere antibodies were negative. Pulmonary function testing (PFT) revealed very severe restrictive lung disease. Barium swallow study was normal. Despite being advised to undergo oesophageal manometry test in view of dysphagia, patient was not willing for the same. Diagnosis of systemic sclerosis was made. Systemic sclerosis is a disease in which extensive fibrosis, vascular alterations and autoantibodies against various cellular antigens being the principal features with a female to male ratio of 4:1. Skin pigmentation changes among other features of skin involvement include a salt-and-pepper appearance due to diffuse hyperpigmentation with sparing of the perifollicular areas. This may be due to the richer capillary network that may warm the perifollicular skin and preserve melanogenesis producing the perifollicular pigment retention in systemic sclerosis.1,2 Both cellular and humoral immune factors in combination with external factors such as trauma or inflammation may trigger the destruction of melanocytes.3 Moreover, various physical factors like temperature changes as well as genetic, hormonal factors may influence pigment formation. Such changes in pigmentation is also seen during repigmentation around hair follicles in vitiligo. Clinically, both vitiligo and depigmented lesions of systemic sclerosis present as chalk-white macules with well-defined borders. However, mucosal involvement is commonly seen in vitiligo while depigmented lesions are usually not observed involving the lips or oral cavity in systemic sclerosis.
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Ramkumar S, Tung M, Cameron J, Pang B, Nerlekar N, Kotschet E, Alison J. Do all patients need intense anticoagulation and antiplatelet regimens following WATCHMAN device implantation? A case series of five patients. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Tung M, Ramkumar S, Cameron J, Pang B, Nerlekar N, Kotschet E, Alison J. Reduced intensity antiplatelet and anticoagulation regimens post WATCHMAN implant. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Padmanabhan S, Juvvadi S, Chithranjan AB, Ramkumar S, Kumar NN. Orthodontic-surgical management of a case of severe mandibular deficiency due to condylar ankylosis. Indian J Dent Res 2014; 25:667-71. [PMID: 25511071 DOI: 10.4103/0970-9290.147122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Dentofacial deformities involve deviations from the normal facial proportions and dental relationships and can range from mild to being severe enough to be severely handicapping.The term handicapping malocclusions though not a term commonly used, involves a fortunately small section (2-4%) of patients who can suffer from esthetic,psychological and functional problems. Craniofacial Orthodontics is the area of orthodontics that treats patients with congenital and acquired deformities of the integument and it's underlying musculoskeletal system within the craniofacial area and associated structures.This case report of a young woman with severe mandibular deficiency and facial asymmetry due to condylar ankylosis highlights the importance of team work in rehabilitation of such severe craniofacial deformities.
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Ramkumar S, Dhingra A, Jyotsna VP, Ganie MA, Das CJ, Seth A, Sharma MC, Bal CS. Ectopic insulin secreting neuroendocrine tumor of kidney with recurrent hypoglycemia: a diagnostic dilemma. BMC Endocr Disord 2014; 14:36. [PMID: 24741994 PMCID: PMC4046058 DOI: 10.1186/1472-6823-14-36] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 03/06/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hypoglycemia secondary to ectopic insulin secretion of non-pancreatic tumors is rare. CASE PRESENTATION We describe a middle aged woman with recurrent hypoglycemia. On evaluation, she was detected to have hyperinsulinemic hypoglycemia and right sided renal mass lesion. 68Ga-Dotanoc and 99mTc-HYNICTOC scans confirmed the intrarenal mass to be of neuroendocrine origin. Right nephrectomy was done and it turned out to be an insulin secreting neuroendocrine tumour. Neuroendocrine nature of this tumour was further confirmed by ultra-structural examination. Her hypoglycemia did not recur after resection of this tumour. CONCLUSION Few cases of ectopic insulin secretion have been reported though some are not proven convincingly. This case addresses all the issues raised in previous case reports and proves by clinical, laboratory, functional imaging and immunohistochemical analysis that ectopic origin of insulin by non-pancreatic tumors does occur. To our knowledge, this is the first reported case of ectopic insulinoma arising from the kidney.
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S R, Kandasamy D, MK V, Tripathi M, VP J. Genu valgum and primary hyperparathyroidism in children. ACTA ACUST UNITED AC 2014. [DOI: 10.5348/ijcri-201455-cs-10041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Ramkumar S, Jyotsna VP, Mallick S, Kachhawa G, Kandasamy D, Kriplani A, Ammini AC. Bilateral thecoma presenting as premenopausal hirsutism: Laproscopic removal. Indian J Endocrinol Metab 2013; 17:S662-S664. [PMID: 24910832 PMCID: PMC4046596 DOI: 10.4103/2230-8210.123561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Hyperandrogenism is a common disorder among women in the reproductive age group. One of the rare causes for androgen excess is sex cord- stromal tumors of the ovary. These are usually unilateral. Here we report case of a 48 year old woman who presented with hyperandrogenism due to bilateral ovarian thecoma. Androgen levels normalized following resection of the tumor. This, to the best of our knowledge, is the first case of bilateral thecoma presenting as hirsutism in a premenopausal woman.
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Karthikeyan G, Ramkumar V, Kumar SP, Ramkumar S, Selvamani S, Vetriveeran B, Karuppasamy N, Moses IC. Intestinal infestation with Fasciolopsis buski leading to acute kidney injury. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2013; 61:936-938. [PMID: 24968560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Fasciolopsis buski is the largest intestinal fluke infecting human beings. This trematode is endemic in certain parts of the country. Migration poses the risk of spread of the worm to other parts of the country. We report fasciolopsis buski in a migrant from Bihar working in Coimbatore, Tamil Nadu. Acute kidney injury following intestinal obstruction occurred in this case which was never described before.
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Ramkumar S, Kaur P, Joshi A, Ammini, AC. Sexual precocity with pituitary macroadenoma and bilateral multicystic ovaries - a case report. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3850435 DOI: 10.1186/1687-9856-2013-s1-p200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ramkumar S, Ammini AC. Early initiation of insulin in a child with T2DM and clinical course - a case report. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3856501 DOI: 10.1186/1687-9856-2013-s1-p26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ramkumar S, Shivprakash, Ammini AC. Precocious puberty and ovarian tumors – 2 case reports. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2013. [PMCID: PMC3850124 DOI: 10.1186/1687-9856-2013-s1-p80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Malathi N, Radhika T, Thamizhchelvan H, Ravindran C, Ramkumar S, Giri G, Gopal D. Psammomatoid juvenile ossifying fibroma of the jaws. J Oral Maxillofac Pathol 2012; 15:326-9. [PMID: 22144839 PMCID: PMC3227263 DOI: 10.4103/0973-029x.86710] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Juvenile ossifying fibroma is an uncommon, benign, bone-forming neoplasm with aggressive local growth that is distinguished from other fibro-osseous lesions primarily by its age of onset, clinical presentation and aggressive behavior. Although a benign entity, juvenile ossifying fibroma is known to be locally aggressive and has a high tendency to recur. Two distinctive microscopic patterns have been described: A trabecular variant and a psammomatoid variant. This latter variant is predominantly a craniofacial lesion and occurs rarely in the jaws. We present herein two cases of psammomatoid juvenile ossifying fibroma involving the jaws. The first case was a mandibular lesion in a 31-year-old female whereas the second case presented with maxillary involvement in a 46-year-old female. In addition, the pathology of the lesion was analyzed with confocal laser scanning microscopy.
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Padmanabhan S, Chitharanjan AB, Ramkumar S, Nandakumar N, Ravindran C. Surgical-orthodontic management of severe sleep apnea. JOURNAL OF CLINICAL ORTHODONTICS : JCO 2011; 45:507-516. [PMID: 22094865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Senthilkumar B, Dhavamani V, Ramkumar S, Philominathan P. Measurement of gamma radiation levels in soil samples from Thanjavur using gamma-ray spectrometry and estimation of population exposure. J Med Phys 2011; 35:48-53. [PMID: 20177570 PMCID: PMC2825004 DOI: 10.4103/0971-6203.55966] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 06/18/2009] [Accepted: 06/25/2009] [Indexed: 12/05/2022] Open
Abstract
This study assesses the level of terrestrial gamma radiation and associated dose rates from the naturally occurring radionuclides 232Th, 238U and 40K in 10 soil samples collected from Thanjavur (Tamil Nadu, India) using γ-ray spectrometry. The activity profile of radionuclides has clearly showed the existence of low level activity in Thanjavur. The geometric mean activity concentrations of 232Th, 238U and 40K is 42.9±9.4 Bq.kg−1, 14.7±1.7 Bq.kg−1 and 149.5±3.1 Bq.kg−1 respectively are derived from all the soil samples studied. The activity concentration of 232Th, 238U and 40K in soil is due to the presence of metamorphic rocks like shale, hornblende-biotite gneiss and quartzofeldspathic gneiss in these areas. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 32 nGy.h−1 and 59.1 nGy.h−1 with an arithmetic mean of 43.3 ±9 nGy.h−1. This value is lesser than the population weighted world-averaged of 60 nGy.h−1. Inhabitants of Thanjavur are subjected to external gamma radiation exposure (effective dose) ranging between 39.2 and 72.6 μSv.y−1 with an arithmetic mean of 53.1±11 μSv.y−1. The values of the external hazard index determined from the soil radioactivity of the study area are less than the recommended safe levels.
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Rajaram S, Brindha JT, Sreedevi KR, Manu A, Thilakavathi A, Ramkumar S, Santhanakrishnan V, Balagurunathan MR, Jesan T, Kannan V, Hegde AG. Evaluation of 25 y of environmental monitoring data around Madras Atomic Power Station (MAPS), Kalpakkam, India. RADIATION PROTECTION DOSIMETRY 2010; 142:314-323. [PMID: 20829204 DOI: 10.1093/rpd/ncq215] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The Environmental Survey Laboratory at Kalpakkam, India carries out elaborate monitoring programme involving atmospheric, terrestrial and aquatic samples for radioactivity to evaluate the impact of operating two pressurised heavy water reactors. This paper presents the evaluation of 25 y (1983-2008) data. Statistical analysis of the environmental data for different radionuclides showed that the data best fits log-normal distribution. The data analysed showed that fission products such as (137)Cs, (90)Sr and (131)I were due to global fallout only. A ratio of 0.2 was obtained for (90)Sr to (137)Cs in air filter samples, only during Chernobyl accident period. The transfer factor of (137)Cs and (90)Sr for rice was computed to be 0.23 and 0.03 and vegetables 0.25 and 0.10, respectively. Activation products (3)H and (41)Ar are the only radionuclides that are related to MAPS operation. A strong correlation (r = 0.9) was observed between (3)H activity in air and (3)H discharged to the atmosphere. A similar correlation (r = 0.8) was observed in (3)H concentration in seawater and (3)H discharged in the liquid waste. The annual internal dose due to (3)H and annual external dose due to (41)Ar evaluated in the last 25 y show that the members of the public received less than 2 % of the dose limit (1 mSv y(-1)) set by ICRP 72.
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Sowmya M, Senthilkumar B, Seshan BRR, Hariharan G, Purvaja R, Ramkumar S, Ramesh R. Natural radioactivity and associated dose rates in soil samples from Kalpakkam, South India. RADIATION PROTECTION DOSIMETRY 2010; 141:239-247. [PMID: 20522563 DOI: 10.1093/rpd/ncq169] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The activity concentration of naturally occurring radioactive elements such as 226Ra, 232Th and 40K were measured for 46 soil samples collected in the vicinity of the Madras atomic power station, Kalpakkam, South India using gamma-ray spectroscopy. The average activity concentration of 226Ra, 232Th and 40K in soil samples were found to be 22.6 ± 12.6, 92.8 ± 44.3 and 434.1 ± 131.1 Bq kg(-1), respectively. The activity concentration of natural radionuclides is higher than the world average except for (226)Ra. The external absorbed gamma dose rates due to 226Ra, 232Th and 40K are observed to be 74.6 ± 30.8 nGy h(-1) with a corresponding annual effective dose of 91.5 ± 37.8 µSv y(-1), which are also above the world average. The values of radium equivalent activity and external hazard index are less than the world average. Whereas, the values of the radioactivity level index (I(γ)) and the total gamma dose rate were found to be above the required criterion.
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Majumder MK, S R, Mahajan DK, Basu S. Coarse-graining scheme for simulating uniaxial stress-strain response of glassy polymers through molecular dynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:011803. [PMID: 20365391 DOI: 10.1103/physreve.81.011803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Indexed: 05/29/2023]
Abstract
Simulation of the deformation of polymers below their glass transition through molecular dynamics provides an useful route to correlate their molecular architecture to deformation behavior. However, present computational capabilities severely restrict the time and length scales that can be simulated when detailed models of these macromolecules are used. Coarse-graining techniques for macromolecular structures intend to make bigger and longer simulations possible by grouping atoms into superatoms and devising ways of determining reasonable force fields for the superatoms in a manner that retains essential macromolecular features relevant to the process under study but jettisons unnecessary details. In this work we systematically develop a coarse-graining scheme aimed at simulating uniaxial stress-strain behavior of polymers below their glass transition. The scheme involves a two step process of obtaining the coarse grained force field parameters above glass transition. This seems to be enough to obtain "faithful" stress-strain responses after quenching to below the glass transition temperature. We apply the scheme developed to a commercially important polymer polystyrene, derive its complete force field parameters and thus demonstrate the effectiveness of the technique.
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Danda AK, S R, Chinnaswami R. Comparison of Gap Arthroplasty With and Without a Temporalis Muscle Flap for the Treatment of Ankylosis. J Oral Maxillofac Surg 2009; 67:1425-31. [DOI: 10.1016/j.joms.2008.12.049] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 09/29/2008] [Accepted: 12/19/2008] [Indexed: 11/15/2022]
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87
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Ramkumar S, Nanda Kumar N. Assessment of the regenerate in distraction osteogenesis. Int J Oral Maxillofac Surg 2009. [DOI: 10.1016/j.ijom.2009.03.211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ramkumar S, Sakac D, Binnington B, Branch DR, Lingwood CA. Induction of HIV-1 resistance: cell susceptibility to infection is an inverse function of globotriaosyl ceramide levels. Glycobiology 2008; 19:76-82. [DOI: 10.1093/glycob/cwn106] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Subhashraj K, Ramkumar S, Ravindran C. Pattern of mandibular fractures in Chennai, India. Br J Oral Maxillofac Surg 2008; 46:126-7. [PMID: 17098339 DOI: 10.1016/j.bjoms.2006.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2006] [Indexed: 10/23/2022]
Abstract
We describe the pattern of mandibular fractures in Chennai, and confirm that, as in most other large cities, the main cause is road traffic accidents.
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Ramkumar S, Kumar N, Ravindran C. A bifocal distractor to create symphysis—the turning point in distraction osteogenesis. Int J Oral Maxillofac Surg 2007. [DOI: 10.1016/j.ijom.2007.08.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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91
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Ramkumar S, Darcy C, Azzawi K, Graham KE. A helpful tip to reduce the incidence of possible implant contamination and capsule formation in breast augmentation. J Plast Reconstr Aesthet Surg 2007; 60:215-6. [PMID: 17223524 DOI: 10.1016/j.bjps.2006.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Accepted: 04/05/2006] [Indexed: 11/26/2022]
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92
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Durrant C, Townley WA, Ramkumar S, Khoo CTK. Forgotten digital tourniquet: salvage of an ischaemic finger by application of medicinal leeches. Ann R Coll Surg Engl 2007; 88:462-4. [PMID: 17002851 PMCID: PMC1964669 DOI: 10.1308/003588406x117052] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Individual finger tourniquets are appropriate to the management of a wide range of conditions presenting to an accident and emergency department. They are simpler and more comfortable to use than upper arm pneumatic tourniquets and commercially available digital tourniquets are not readily available in the accident and emergency unit. However, if a finger tourniquet is overlooked, ischaemia of the digit results, and gangrene may follow if the problem is not defused early enough, leading to potential disaster. We present one case where a digit was salvaged after 4 days of tourniquet application, using medicinal leeches.
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Ramkumar S, Narayanan V, Laing JHE. Twenty-four hours or 10 days? A prospective randomised controlled trial in children comparing head bandages following pinnaplasty. J Plast Reconstr Aesthet Surg 2006; 59:969-74. [PMID: 16920590 DOI: 10.1016/j.bjps.2006.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 01/27/2006] [Accepted: 01/27/2006] [Indexed: 10/24/2022]
Abstract
The perceived benefits of bandaging for 10 days following pinnaplasty have been questioned by previous studies. The problems arising from these dressings are many [Powell BWEM. The value of head dressings in the postoperative management of the prominent ear. Br J Plast Surg 1989;42:692-4. Bartley J. How long should ears be bandaged after otoplasty? J Laryngol Otol 1998;112:531-2. Wong MC, Sylaidis P. Head dressings for pinnaplasty: a tradition not supported by evidence. Br J Plast Surg 2001;54:81-2], including their slippage [Powell BWEM. The value of head dressings in the postoperative management of the prominent ear. Br J Plast Surg 1989;42:692-4. Bradbury ET, Hewison J, Timmons MJ. Psychological and social outcome of prominent ear correction in children. Br J Plast Surg 1992;45:97-100. Jeffery SLA. Complications following correction of prominent ears: an audit review of 122 cases. Br J Plast Surg 1999;52:588-90]. Eighty children were recruited into a prospective randomised controlled trial comparing the use of a head bandage for only 24 h with a standard practise of a 10-day head bandage. A preoperative measurement of the lateral ear projection (LEP) was made. The outcome measures recorded during the two planned postoperative visits at 10 days (visit 1) and 2 months (visit 2) were: patient satisfaction score, LEP, complications and any unscheduled hospital visits associated with the surgery. There was no significant difference in LEP and patient satisfaction between the two groups at both the scheduled postoperative visits. Differences between the groups in the number of unscheduled visits (p=0.21) did not reach statistical significance. The findings indicate that it is safe and effective to use head bandage for only 24 h following surgical correction of prominent ears. This study shows no benefit from the application of a formal head bandage for any longer than 1 day.
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Enguidanos L, Pfleiderer A, Smith W, Ramkumar S. Pneumomediastinum secondary to an apparently trivial stab wound to the neck: the value of the Hamman's sign and thorough radiological investigation. Emerg Med J 2005; 22:230-1. [PMID: 15735284 PMCID: PMC1726708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Perforation of the pharynx and upper oesophagus after stab wounds to the neck is easily overlooked because of the relative lack of symptoms. A case is reported in which pneumomediastinum occurred after an apparently trivial neck wound.
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Ramkumar S, Josty IC, Sykes PJ. Severe extensor tendon attrition and multiple tendon ruptures resulting from Kienböck's disease. Ann Plast Surg 2000; 45:647-50. [PMID: 11128766 DOI: 10.1097/00000637-200045060-00014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Kienböck's disease is a rare but recognized cause of chronic wrist pain. Occasionally, complications arise leading to tendon rupture. The authors present the first reported case of attrition to all extensors of the hand, and extensor tendon rupture to the little finger in a patient with a 45-year history of Kienböck's disease. This is also the first reported incidence of this complication in whites. Clinical features, surgical management, and the successful outcome are discussed.
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Sanyal S, Sood AK, Ramkumar S, Ramaswamy S, Kumar N. Novel polarization dependence in diffusing-wave spectroscopy of crystallizing colloidal suspensions. PHYSICAL REVIEW LETTERS 1994; 72:2963-2966. [PMID: 10056029 DOI: 10.1103/physrevlett.72.2963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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