Amit Mitra
University of Minnesota - Twin Cities, Genetics, Faculty Member
Research Interests: Engineering, Applied Mathematics, Statistics, Statistical Signal Processing, Control, and 14 moreBusiness and Management, Mathematical Sciences, Cramer Rao Lower Bound, American, Simulation Study, Simulation experiment, Discrete random variable, Small samples, Stable Distribution, Multivariate Normal Distribution, Electrical And Electronic Engineering, Information Sciences, Asymptotic Properties, and Additive noise(Business and Management, Mathematical Sciences, Cramer Rao Lower Bound, American, Simulation Study, Simulation experiment, Discrete random variable, Small samples, Stable Distribution, Multivariate Normal Distribution, Electrical And Electronic Engineering, Information Sciences, Asymptotic Properties, and Additive noise)
(Business and Management, Mathematical Sciences, Cramer Rao Lower Bound, American, Simulation Study, Simulation experiment, Discrete random variable, Small samples, Stable Distribution, Multivariate Normal Distribution, Electrical And Electronic Engineering, Information Sciences, Asymptotic Properties, and Additive noise)
ABSTRACT In this paper, we consider the problem of estimating the number of components of a superimposed nonlinear sinusoids model of a signal in the presence of additive noise. We propose and provide a detailed empirical comparison of... more
ABSTRACT In this paper, we consider the problem of estimating the number of components of a superimposed nonlinear sinusoids model of a signal in the presence of additive noise. We propose and provide a detailed empirical comparison of robust methods for estimation of the number of components. The proposed methods, which are robust modifications of the commonly used information theoretic criteria, are based on various M-estimator approaches and are robust with respect to outliers present in the data and heavy-tailed noise. The proposed methods are compared with the usual non-robust methods through extensive simulations under varied model scenarios. We also present real signal analysis of two speech signals to show the usefulness of the proposed methodology.
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Coronary artery disease, leading to myocardial infarction and ischaemia, affects millions of persons and is one of the leading causes of morbidity and mortality worldwide. Invasive techniques such as coronary artery bypass grafting are... more
Coronary artery disease, leading to myocardial infarction and ischaemia, affects millions of persons and is one of the leading causes of morbidity and mortality worldwide. Invasive techniques such as coronary artery bypass grafting are used to alleviate the sequelae of arterial occlusion. Unfortunately, restenosis or occlusion of the grafted conduit occurs over a time frame of months to years with a gradual reduction in patency, especially in vein grafts. The events leading to intimal hyperplasia (IH) formation involve numerous cellular and molecular components. Various cellular elements of the vessel wall are involved as are leucocyte-endothelial interactions that trigger the coagulation cascade leading to localized thrombus formation. Subsequent phenotypic modification of the medial smooth muscle cells and their intimal migration is the basis of the lesion formation that is thought to be propagated by an immune-mediated reaction. Despite intense scrutiny, the pathophysiology of IH...
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Internal mammary artery (IMA) coronary artery bypass grafts (CABG) are remarkably resistant to intimal hyperplasia (IH) as compared to saphenous vein (SV) grafts following aorto-coronary anastomosis. The reason behind this puzzling... more
Internal mammary artery (IMA) coronary artery bypass grafts (CABG) are remarkably resistant to intimal hyperplasia (IH) as compared to saphenous vein (SV) grafts following aorto-coronary anastomosis. The reason behind this puzzling difference still remains an enigma. In this study, we examined the effects of IGF-1 stimulation on the PI3K-AKT/PKB pathway mediating proliferation of smooth muscle cells (SMCs) of IMA and SV origin and the specific contribution of phosphatase and tensin homologue (PTEN) in regulating the IGF-1-PI3K-AKT/PKB axis under these conditions. Mitogenic activation with IGF-1, time-dependently stimulated the phosphorylation of PI3K and AKT/PKB in the SV SMCs to a much greater extent than the IMA. Conversely, PTEN was found to be significantly more active in IMA SMCs. Transient overexpression of PTEN in SMCs of SV and IMA inhibited AKT/PKB activity and upstream of AKT/PKB, caused a reduction of IGF-1 receptors. Downstream, PTEN overexpression in SV SMCs induced the...
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Research Interests: Enterprise Architecture, Natural Language Processing, OPERATING SYSTEM, Meta-model, Life Cycle, and 10 moreEnvironment and Development, Development Methodology, Web Service, Domain Specificity, Model Generation, Development Process, Department of Defense, Service Provider, Simulation Model, and Rule Based
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Low-velocity firearms represent the majority of civilian gunshot wounds to the hand, yet much of the literature is based on high-velocity injuries. The authors reviewed their treatment regimen for civilian gunshot wounds to the hand and... more
Low-velocity firearms represent the majority of civilian gunshot wounds to the hand, yet much of the literature is based on high-velocity injuries. The authors reviewed their treatment regimen for civilian gunshot wounds to the hand and offer a treatment algorithm that emphasizes early debridement and fracture stabilization. They also address the economic impact on society. The authors reviewed 121 fractures in 90 patients with gunshot wounds to the hand treated at an urban trauma center during the last 5 years. All patients were managed with irrigation and debridement, elevation, intravenous antibiotics, and early fracture stabilization. Sixty fractures were managed with rigid internal or external fixation: Kirshner wires (26%), miniplates (16%), and external fixation (8%). Fifty-six fractures were managed with closed reduction. Five fractures required amputation. There was one subsequent infection and two late amputations. The cost of hospitalization and operative care was more than $1.7 million. For gunshot wounds to the hand the authors advocate immediate irrigation and debridement, intravenous antibiotics, early fracture stabilization, and a low threshold for internal fixation. This regimen is supported by their low infection and complication rates.
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The purpose of this article is to report the increased incidence of community-acquired methicillin-resistant S. aureus in hand infections at an urban medical center. The authors performed a retrospective review of all patients with hand... more
The purpose of this article is to report the increased incidence of community-acquired methicillin-resistant S. aureus in hand infections at an urban medical center. The authors performed a retrospective review of all patients with hand infections over a 21-month period, and all patients with culture-positive methicillin-resistant S. aureus were identified. Cases determined to be nosocomial were excluded. The study period was divided into three 7-month periods. A total of 343 hand infections were treated over a 21-month period. Eighty-nine patients (26 percent) with culture positive methicillin-resistant S. aureus were identified; of these, 75 were determined to be community-acquired methicillin-resistant S. aureus patients. Statistical analysis was performed using the Fisher's exact test (p < 0.0001), the chi-square test for equal proportions, the Cochran-Armitage trend test, and two-way analysis of variance. The demographics of the patients were compared using two-way analy...
Research Interests: Algorithms, Comorbidity, Plastic and Reconstructive Surgery, Humans, Female, and 15 moreMale, Staphylococcus aureus, Plastic, Risk factors, Clinical Sciences, Philadelphia, Prevalence, Middle Aged, Adult, Retrospective Studies, Methicillin Resistance, Hand, Urban Population, Risk Factors, and Methicillin Resistant Staphylococcus Aureus
Inheritance of common genetic variants at one or more base excision repair (BER) genes may result in a reduced DNA repair capacity and in an increased risk of cancers like breast cancer. The present case-control study with 390 north... more
Inheritance of common genetic variants at one or more base excision repair (BER) genes may result in a reduced DNA repair capacity and in an increased risk of cancers like breast cancer. The present case-control study with 390 north Indian women (155 breast cancer cases and 235 controls) was aimed to investigate the association of seven nonsynonymous BER gene polymorphisms viz. rs1130409/T1865G (APEX1), rs1799782/T22142C (XRCC1), rs25487/G23990A (XRCC1), rs4989588/T3337A (FEN1), rs4989586/ G3259A (FEN1), rs4989587/C3315T (FEN1), and rs1050525/G6941T (PCNA) with breast cancer susceptibility. Statistically significant association with breast cancer risk was observed for rs1130409 homozygous mutant GG [odds ratio (OR) 3.35, 95% confidence interval (CI) 1.36-8.26), heterozygous GT (OR 2.42, 95% CI 1.56-3.76), and combined mutant (GT + GG) (OR 2.52, 95% CI 1.65-3.86] genotypes and rs25487 homozygous mutant AA (OR 2.91, 95% CI 1.66-5.10) and combined mutant (AA + AG) (OR 1.41, 95% CI 0.90...
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Research Interests: Pakistan, Cleft Palate, Cleft Lip and Palate, Resource use, Plastic and Reconstructive Surgery, and 16 morePregnancy, Humans, Female, Male, Plastic, Incidence, Risk factors, Clinical Sciences, Newborn Infant, Adult, Consanguinity, Cleft Lip, Risk Factors, Epidemiologic Studies, Laboratory Tests, and Prenatal Care
Intimal hyperplasia occurs primarily as a part of the pathogenesis of coronary artery disease or secondary to therapeutic intervention in relieving vascular occlusion. Intimal hyperplasia involving vascular smooth muscle cells is found in... more
Intimal hyperplasia occurs primarily as a part of the pathogenesis of coronary artery disease or secondary to therapeutic intervention in relieving vascular occlusion. Intimal hyperplasia involving vascular smooth muscle cells is found in atherosclerosis, post-balloon angioplasty restenosis, in-stent restenosis and vein graft disease, predominantly involving the use of saphenous vein conduits in coronary artery bypass grafting procedures. One potentially exciting area is that of gene therapy. Gene and protein expression patterns at the site of vasculoproliferative lesions have been widely studied and several target areas have been identified on the basis of whether the gene has an antiproliferative, proapoptotic, matrix degrading or endothelial protective action. Blood vessels are easily accessible for the delivery of the gene product, and experimental studies using animal models have used catheter-delivered gene products at the site of vascular injury. Currently, the application of antisense technology and adenoviral vector-mediated delivery has shown significant promise, albeit in in vitro or animal model settings. In this review, we discuss the current knowledge in the application of gene therapy in fibroproliferative vasculopathies. We examine some of the cellular mechanisms and intermediaries which could be potential candidates for gene targeting. We also present some of the advances in biomedical technology that might provide useful vehicles for pinpoint delivery of the gene product. Could the future of restenosis treatment be in gene therapy or is it misplaced enthusiasm?
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Cytochrome P-450 (CYP) 1A1 is a candidate gene for low penetrance breast cancer (BC) susceptibility. Evidences demonstrate that ethnic differences in BC incidence may be partly due to genetic factors, including polymorphisms in the genes.... more
Cytochrome P-450 (CYP) 1A1 is a candidate gene for low penetrance breast cancer (BC) susceptibility. Evidences demonstrate that ethnic differences in BC incidence may be partly due to genetic factors, including polymorphisms in the genes. In the present case control study four CYP1A1 gene polymorphisms, m1 (T6235C), m2 (A4889G), m3 (T5639C), and m4 (C4887A) were studied for their association with BC conjointly with the known risk factors such as age, menopausal status, diet, and life style. Polymorphisms of CYP1A1 gene were detected by PCR-RFLP method. The homozygous mutant (G/G) of m2 polymorphism was significantly associated with BC. Consequently, association of both m2 heterozygous mutant genotype (A/G) and combined group [homozygous (G/G) plus heterozygous (A/G) mutant genotype] showed association with postmenopausal women. Incidences of BC were also found to be independent of clinicopathological factors except heterozygous mutant genotype (A/G) m2 showed association with dietary factors and high grade tumors while homozygous mutant (G/G) m2 showed association with ER/PR-positive BC cases. Wild-type m3 was observed in all the subjects in cases as well as in controls. No significant association was observed between m1 and m3 polymorphisms and BC risk in all the subjects as well as when stratified into pre- and postmenopausal subjects. This indicates that out of ml and m2 polymorphisms that have been reported in Asians, only m2 is associated with North Indians.
Research Interests: Oncology, Polymorphism, Breast Cancer, Diet, India, and 8 moreHumans, Mutation, Female, Risk factors, Aged, Middle Aged, Adult, and Risk Factors
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Research Interests: Kidney diseases, Cytokines, Inflammation, Lipopolysaccharide, Erythropoietin, and 15 moreAcute renal failure, Kidney, Mice, Nitric oxide, Animals, Male, Sepsis, Superoxide Dismutase, Clinical Sciences, Super oxide dismutase, Lipopolysaccharides, ENDOTOXEMIA, Tumor necrosis factor-alpha, Renal Dysfunction, and Glomerular Filtration Rate
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Cytosolic... more
Cytosolic 5&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-nucleotidase II (NT5C2) is involved in the development of 1-β-d-arabinofuranosylcytosine (ara-C) resistance and has been associated with clinical outcome in patients receiving ara-C-based chemotherapy. NT5C2 inactivates ara-C by dephosphorylating ara-C monophosphate to ara-C. In this study, we sequenced NT5C2 in genomic DNA samples from International HapMap project panels with European [Centre d&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;Etude du Polymorphisme Humain (CEU); n = 90] or African [Yoruba people in Ibadan, Nigeria (YRI); n = 90] ancestry. We identified 41 genetic variants [one insertion-deletion and 40 single nucleotide polymorphisms (SNPs)], including three nonsynonymous SNPs (Y3A, K47R, and Q136R). Twenty-five SNPs were novel and 16 overlapped with the HapMap data. Subjects with African ancestry had NT5C2 mRNA expression levels that was significantly higher than those with European ancestry (p = 0.005). Furthermore, there was a correlation between NT5C2 mRNA expression and ara-C sensitivity in CEU but not in YRI cell lines. None of the nonsynonymous SNPs demonstrated any effect on NT5C2 activity. The genotypes of several SNPs were significantly associated with NT5C2 mRNA expression and/or ara-C sensitivity in CEU cell lines, but very few were significant in YRI cell lines. Of most interest, SNPs (linkage disequilibrium group CEU.12) in the 5&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;-untranslated region were associated with NT5C2 expression and ara-C sensitivity in HapMap cell lines and with NT5C2 mRNA expression and ara-C sensitivity in diagnostic leukemic blasts from pediatric patients with acute myeloid leukemia. Functional genomics analysis demonstrated that the promoter SNP rs11191612 was associated with altered luciferase activation in reporter assays and altered DNA-protein binding in gel shift assays. These results suggest that genetic variations in NT5C2 influence its expression and, potentially, cellular responses to nucleoside analogs.
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Research Interests: Polymorphism, Breast Cancer, DNA repair, India, Association study, and 19 moreHead and Neck, Humans, Female, Polymerase Chain Reaction, Squamous Cell Carcinoma, Statistical Significance, Nucleotide Excision Repair, Risk factors, Oral Squamous Cell Carcinoma (OSCC), Experimental, Genotype, Single Nucleotide Polymorphism, Group, Genomic instability, Asian Continental Ancestry Group, Risk Factors, Case Control Study, Confidence Interval, and Case Control Studies(Head and Neck, Humans, Female, Polymerase Chain Reaction, Squamous Cell Carcinoma, Statistical Significance, Nucleotide Excision Repair, Risk factors, Oral Squamous Cell Carcinoma (OSCC), Experimental, Genotype, Single Nucleotide Polymorphism, Group, Genomic instability, Asian Continental Ancestry Group, Risk Factors, Case Control Study, Confidence Interval, and Case Control Studies)
(Head and Neck, Humans, Female, Polymerase Chain Reaction, Squamous Cell Carcinoma, Statistical Significance, Nucleotide Excision Repair, Risk factors, Oral Squamous Cell Carcinoma (OSCC), Experimental, Genotype, Single Nucleotide Polymorphism, Group, Genomic instability, Asian Continental Ancestry Group, Risk Factors, Case Control Study, Confidence Interval, and Case Control Studies)
Acute renal failure (ARF), characterized by sudden loss of the ability of the kidneys to excrete wastes, concentrate urine, conserve electrolytes, and maintain fluid balance, is a frequent clinical problem, particularly in the intensive... more
Acute renal failure (ARF), characterized by sudden loss of the ability of the kidneys to excrete wastes, concentrate urine, conserve electrolytes, and maintain fluid balance, is a frequent clinical problem, particularly in the intensive care unit, where it is associated with a mortality of between 50% and 80%. In this review, the epidemiology and pathophysiology of ARF are discussed, including the vascular, tubular, and inflammatory perturbations. The clinical evaluation of ARF and implications for potential future therapies to decrease the high mortality are described.
Research Interests: Early Intervention, Acute kidney injury, Inflammation, World War II, Vietnam, and 13 moreCritical Care, Acute renal failure, Humans, INTENSIVE CARE, Clinical, Hemodialysis, Experimental Study, Intensive Care Unit, Urinary Tract, Clinical Investigation, Renal Replacement Therapy, Clinical evaluation, and Experimental Model
I. INTRODUCTION IN MANY problems in signal processing, the signal model is a function of a set of parameters that is dependent upon some integer order . CramérRao bounds (CRB) and estima-tion methods are then often derived for the... more
I. INTRODUCTION IN MANY problems in signal processing, the signal model is a function of a set of parameters that is dependent upon some integer order . CramérRao bounds (CRB) and estima-tion methods are then often derived for the parameter vector as-suming the ...
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Page 1. SPECIAL ARTICLES Exchange Rate of the Rupee and Purchasing Power Parity Ashok K Nag Amit-Mitra The authors examine the rupee-dollar rate, the principal exchange rate in the Indian market, in the light of the Purchasing Power... more
Page 1. SPECIAL ARTICLES Exchange Rate of the Rupee and Purchasing Power Parity Ashok K Nag Amit-Mitra The authors examine the rupee-dollar rate, the principal exchange rate in the Indian market, in the light of the Purchasing Power Parity theory. ...