Browsing by Author "Krishnakumar, N"

Now showing 1 - 11 of 11
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    Acute phase reactants predict mitral regurgitation following mitral valvuloplasty
    (INTERNATIONAL JOURNAL OF CARDIOLOGY, 2006) Harikrishnan, S; Rajeev, E; Tharakan, JA; Thomas, T; Ajith, K; Sivasankaran, S; Krishnamoorthy, KM; Santhosh, D; Krishnakumar, N; Namboodiri, KKN
    This report evaluated whether acute phase reactants can predict the development of mitral regurgitation following percutaneous mitral valvotomy. 58 patients who developed significant mitral regurgitation following valvotomy were retrospectively compared with 58 age, sex and procedure technique matched control patients, who had valvotomy without mitral regurgitation. ESR and total leucocyte count were significantly higher in the group who developed mitral regurgitation, than in the control group. Higher ESR and total leucocyte count may be indicative of ongoing low grade sub-clinical inflammatory process, which makes the valve tissue friable which can give way during balloon stretch and lead onto mitral regurgitation. (c) 2005 Published by Elsevier Ireland Ltd.
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    Combined Mitral and Pulmonary Valvotomy with Inoue Balloon in Rheumatic Quadrivalvular Disease
    (JOURNAL OF HEART VALVE DISEASE, 2011) Harikrishnan, S; Bijulal, S; Krishnakumar, N; Ajithkumar, VK
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    Endogenous porphyrin fluorescence as a biomarker for monitoring anti-angiogenic effect in antitumor response to hesperetin loaded nanoparticles in experimental oral carcinogenesis
    (RSC Advances, 2014-09) Krishnakumar, N; Gurushankar, K; Gohulkumar, M; Nazeer, SS; Jayasree, RS; Madhavan, NR
    The purpose of the present study is to evaluate the antitumor efficacy of hesperetin loaded nanoparticles (HETNPs) in comparison with native hesperetin (HET) for monitoring endogenous porphyrin emission against 7,12-dimethyl benz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. The effort has been further complemented by immunohistochemical analysis in an attempt to provide a correlation between the emission intensity of endogenous porphyrin and changes in the vascular endothelial growth factor (VEGF) expression observed in control and the experimental animals. A total of 60 autofluorescence spectra were successfully acquired from different anatomic locations of the control and the experimental tissues. Significant differences in the autofluorescence spectral signatures between the control and that of experimental animals have been noticed under the excitation wavelength of 410 nm with emission ranging from 440–750 nm. DMBA-induced tumor tissues are associated with increased endogenous porphyrin emissions at 630 nm, 670 nm and 705 nm. Moreover, oral administration of HET and its nanoparticulates restored the status of endogenous porphyrin emission in the buccal mucosa of DMBA-painted animals. On a comparative basis, the treatment of nanoparticulate hesperetin was found to be more effective than native hesperetin in reducing the formation of squamous cell carcinoma and in improving the status of endogenous porphyrins to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. These endogenous porphyrin emissions may be used as a spectral biomarker for monitoring tumor hypervascularity. The hypervascularity in tumors might be due to angiogenesis. Complementary immunohistochemical analysis of the DMBA-induced tumor tissues showed an abundant expression of VEGF (a marker used for angiogenesis), suggesting that increased endogenous porphyrin intensities may be correlated with angiogenesis. Furthermore, the spectral data are also analyzed using a multivariate data analysis and yielded diagnostic sensitivities of 100%, 76.0%, 93.0% and 80.0% and specificities of 100%, 73.3%, 86.0% and 86.6%, respectively, for classification of control vs.DMBA, DMBA vs. DMBA + HET, DMBA vs. DMBA + HETNPs and DMBA + HET vs. DMBA + HETNPs treated tissues. The present study further suggests that endogenous porphyrin fluorescence could be considered as a reliable spectral marker and a very useful tool for monitoring the anti-angiogenic effect of cancer.
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    Endogenous porphyrin fluorescence as a biomarker for monitoring the anti-angiogenic effect in antitumor response to hesperetin loaded nanoparticles in experimental oral carcinogenesis
    (RSC ADVANCES, 2014) Gurushankar, K; Nazeer, SS; Gohulkumar, M; Jayasree, RS; Nirmal, MR; Krishnakumar, N
    The purpose of the present study is to evaluate the antitumor efficacy of hesperetin loaded nanoparticles (HETNPs) in comparison with native hesperetin (HET) for monitoring endogenous porphyrin emission against 7,12-dimethyl benz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. The effort has been further complemented by immunohistochemical analysis in an attempt to provide a correlation between the emission intensity of endogenous porphyrin and changes in the vascular endothelial growth factor (VEGF) expression observed in control and the experimental animals. A total of 60 autofluorescence spectra were successfully acquired from different anatomic locations of the control and the experimental tissues. Significant differences in the autofluorescence spectral signatures between the control and that of experimental animals have been noticed under the excitation wavelength of 410 nm with emission ranging from 440-750 nm. DMBA-induced tumor tissues are associated with increased endogenous porphyrin emissions at similar to 630 nm, similar to 670 nm and similar to 705 nm. Moreover, oral administration of HET and its nanoparticulates restored the status of endogenous porphyrin emission in the buccal mucosa of DMBA-painted animals. On a comparative basis, the treatment of nanoparticulate hesperetin was found to be more effective than native hesperetin in reducing the formation of squamous cell carcinoma and in improving the status of endogenous porphyrins to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. These endogenous porphyrin emissions may be used as a spectral biomarker for monitoring tumor hypervascularity. The hypervascularity in tumors might be due to angiogenesis. Complementary immunohistochemical analysis of the DMBA-induced tumor tissues showed an abundant expression of VEGF (a marker used for angiogenesis), suggesting that increased endogenous porphyrin intensities may be correlated with angiogenesis. Furthermore, the spectral data are also analyzed using a multivariate data analysis and yielded diagnostic sensitivities of 100%, 76.0%, 93.0% and 80.0% and specificities of 100%, 73.3%, 86.0% and 86.6%, respectively, for classification of control vs. DMBA, DMBA vs. DMBA + HET, DMBA vs. DMBA + HETNPs and DMBA + HET vs. DMBA + HETNPs treated tissues. The present study further suggests that endogenous porphyrin fluorescence could be considered as a reliable spectral marker and a very useful tool for monitoring the anti-angiogenic effect of cancer.
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    Entrapped catheter in the left ventricular posterior venous radicle of the coronary sinus in a case of hemianomalous pulmonary venous connection of left pulmonary veins to coronary sinus
    (INTERNATIONAL JOURNAL OF CARDIOLOGY, 2007) Krishnakumar, N; Misra, M; Dora, S; Bohora, SR
    A 25-year old acyanotic lady with unclear pulmonary venous drainage and a dilated coronary sinus was catheterized. Left pulmonary veins drained into coronary sinus in a left pulmonary vein angiogram done through the coronary sinus with a National Institute of Health 7F catheter. After the angiogram, the catheter got entrapped in a coronary sinus tributary and could be removed only by surgery. The left pulmonary veins were rerouted into the left atrium by unroofing the coronary sinus. Surgery is the treatment of choice for entrapped catheters when the primary condition itself merits surgical correction. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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    Evaluation of Antitumor Activity of Hesperetin-Loaded Nanoparticles Against DMBA-Induced Oral Carcinogenesis Based on Tissue Autofluorescence Spectroscopy and Multivariate Analysis
    (J Fluoresc, 2015-06) Gurushankar, K; Nazeer, SS; Jayasree, RS; Krishnakumar, N
    The present study is designed to understand the nature of endogenous fluorophores and cellular metabolism that occur in the experimental oral carcinogenesis and to assess their feasibility for antitumor efficacy of hesperetinloaded nanoparticles (HETNPs) in comparison with native hesperetin (HET) against 7,12-dimethyl benz(a) anthracene (DMBA)-induced oral carcinogenesis using fluorescence spectroscopy. The fluorescence emission spectra of the control and the experimental buccal mucosa are recorded at an excitation wavelength of 320 nm with an emission ranging from 350 to 550 nm. The results show that there is a reduced contribution from the emission of collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), inDMBA-induced tumor tissues as compared with the control tissues. Furthermore, there was significant decrease in the optical redox ratio [(FAD/ (NADH+FAD)] is observed in DMBA-induced tumor tissues, which indicates an increased metabolic activity when compared to the control tissues. Oral administration of HET and its nanoparticulates restored the status of endogenous fluorophores emission and would have a higher redox ratio in the buccal mucosa of DMBA painted animals. Taken together, the treatment of nanoparticulate hesperetin was found to be more effective than native hesperetin in improving the status of endogenous fluorophores to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. The results of this study raise the important possibility that fluorescence spectroscopy in conjunction with PC-LDA has tremendous potential for monitor or potentially predict response to therapy
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    Monitoring the metabolic response of nanoencapsulated silibinin treatment in DMBA-induced oral carcinogenesis using endogeneous fluorescence
    (Analytical Methods, 2014-10) Krishnakumar, N; Gohulkumar, M; Nazeer, SS; Jayasree, RS; Gurushankar, K
    Autofluorescence spectroscopy is a very sensitive tool for detecting early metabolic response after cancer treatment. The present work aims to investigate the chemopreventive effect of the prepared silibinin-loaded nanoparticles (SILNPs) relative to the efficacy of free silibinin (SIL) for monitoring the changes in the endogenous fluorophore emission and to quantify the metabolic changes in the redox state during 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis using autofluorescence spectroscopy. Significant differences in the autofluorescence spectral signatures between the control and the experimental animals have been noticed under the excitation wavelength at 320 nm with emission ranging from 350–550 nm. The tumor tissues are characterized by a decrease in the emission of collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) compared to the control tissues. Further, the optical oxidation–reduction (redox) ratio is a measure of cellular metabolism and can be determined by the relative change in the fluorescence emission intensity of NADH and FAD. The optical redox ratio will provide sufficient information on metabolic changes associated with tumor transformation. The results revealed that a significant decrease in the optical redox ratio is observed in DMBA-induced tumor tissues, which indicates increased metabolic activity compared to the control tissues. Moreover, an oral administration of SIL and its nanoparticulates restored the status of endogenous fluorophore emission and led to a higher redox ratio in the buccal mucosa of DMBA-painted animals. On a comparative basis, treatment with nanoparticulate silibinin was found to be more effective than free silibinin for reducing the formation of squamous cell carcinoma and improving the status of endogenous fluorophore emission to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. Furthermore, the diagnostic algorithms based on principal component analysis followed by linear discriminant analysis (PC–LDA) achieved an overall diagnostic sensitivity of 96.46% and specificity of 93.64% for separating the control from the experimental groups. The results of this study further suggest that the fluorescence spectroscopic technique in conjunction with PC–LDA has a potential for rapid and sensitive detection of specific metabolic alteration and changes in the endogenous fluorophores in response to anti-cancer drug treatments.
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    Monitoring the metabolic response to nanoencapsulated silibinin treatment in DMBA-induced oral carcinogenesis using endogenous fluorescence
    (ANALYTICAL METHODS, 2014) Gohulkumar, M; Nazeer, SS; Jayasree, RS; Gurushankar, K; Krishnakumar, N
    Autofluorescence spectroscopy is a very sensitive tool for detecting early metabolic response after cancer treatment. The present work aims to investigate the chemopreventive effect of the prepared silibinin-loaded nanoparticles (SILNPs) relative to the efficacy of free silibinin (SIL) for monitoring the changes in the endogenous fluorophore emission and to quantify the metabolic changes in the redox state during 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch (HBP) carcinogenesis using autofluorescence spectroscopy. Significant differences in the autofluorescence spectral signatures between the control and the experimental animals have been noticed under the excitation wavelength at 320 nm with emission ranging from 350-550 nm. The tumor tissues are characterized by a decrease in the emission of collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) compared to the control tissues. Further, the optical oxidation-reduction (redox) ratio is a measure of cellular metabolism and can be determined by the relative change in the fluorescence emission intensity of NADH and FAD. The optical redox ratio will provide sufficient information on metabolic changes associated with tumor transformation. The results revealed that a significant decrease in the optical redox ratio is observed in DMBA-induced tumor tissues, which indicates increased metabolic activity compared to the control tissues. Moreover, an oral administration of SIL and its nanoparticulates restored the status of endogenous fluorophore emission and led to a higher redox ratio in the buccal mucosa of DMBA-painted animals. On a comparative basis, treatment with nanoparticulate silibinin was found to be more effective than free silibinin for reducing the formation of squamous cell carcinoma and improving the status of endogenous fluorophore emission to a near normal range in DMBA-induced hamster buccal pouch carcinogenesis. Furthermore, the diagnostic algorithms based on principal component analysis followed by linear discriminant analysis (PC-LDA) achieved an overall diagnostic sensitivity of 96.46% and specificity of 93.64% for separating the control from the experimental groups. The results of this study further suggest that the fluorescence spectroscopic technique in conjunction with PC-LDA has a potential for rapid and sensitive detection of specific metabolic alteration and changes in the endogenous fluorophores in response to anti-cancer drug treatments.
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    Multifunctional amino functionalized graphene quantum dots wrapped upconversion nanoparticles for photodynamic therapy and X-ray CT imaging.
    (Inorganic Chemistry Communications,, 2023-03) Anjusha, AJ; Thirunavukkarasu, S; Resmi, AN; Jayasree, RS; Dhanapandian, S; Krishnakumar, N
    Herein, we designed and developed a multifunctional nanocomposites by complexing NaGdF4:Yb/Er nanoparticles (UCNPs) with amino functionalized graphene quantum dots (af-GQDs). In the as-prepared nanocomposite (af-GQD/UCNPs), properties of UCNPs and af-GQDs were incorporated into a single nanoplatform to endow therapeutic and diagnostic functions. The UCNPs were employed as an imaging probe and a contrast agent for CT imaging, and the af-GQDs served as a therapeutic agent and photosensitizer (PS) by generating singlet oxygen for photodynamic therapy (PDT). Furthermore, the nanocomposites were investigated by electron microscopy, FTIR spectroscopy, zeta potential measurement, UV–vis spectroscopy, upconversion luminescence measurement, and cytotoxicity assessment. The in vitro experiments displayed excellent X-ray attenuation ability and PDT effects of af-GQD/UCNPs. Hence, the proposed multifunctional nanocomposites, which possesses upconversion luminescence, photodynamic, and X-ray attenuation properties, might be a viable option for application in bio-imaging and photodynamic therapy.
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    Optical redox ratio using endogenous fluorescence to assess the metabolic changes associated with treatment response of bioconjugated gold nanoparticles in streptozotocin-induced diabetic rats
    (Laser Physics Letters, 2017-12) Adavallan, K; Gurushankar, K; Nazeer, SS; Gohulkumar, M; Jayasree, RS; Krishnakumar, N
    Fluorescence spectroscopic techniques have the potential to assess the metabolic changes during disease development and evaluation of treatment response in a non-invasive and label-free manner. The present study aims to evaluate the effect of mulberry-mediated gold nanoparticles (MAuNPs) in comparison with mulberry leaf extract alone (MLE) for monitoring endogenous fluorophores and to quantify the metabolic changes associated with mitochondrial redox states during streptozotocin-induced diabetic liver tissues using fluorescence spectroscopy. Two mitochondrial metabolic coenzymes, reduced nicotinamide dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD) are autofluorescent and are important optical biomarkers to estimate the redox state of a cell. Significant differences in the autofluorescence spectral signatures between the control and the experimental diabetic animals have been noticed under the excitation wavelength at 320 nm with emission ranging from 350–550 nm. A direct correlation between the progression of diabetes and the levels of collagen and optical redox ratio was observed. The results revealed that a significant increase in the emission of collagen in diabetic liver tissues as compared with the control liver tissues. Moreover, there was a significant decrease in the optical redox ratio (FAD/(FAD + NADH)) observed in diabetic control liver tissues, which indicates an increased oxidative stress compared to the liver tissues of control rats. Further, the extent of increased oxidative stress was confirmed by the reduced levels of reduced glutathione (GSH) in diabetic liver tissues. On a comparative basis, treatment with MAuNPs was found to be more effective than MLE for reducing the progression of diabetes and improving the optical redox ratio to a near normal range in streptozotocin-induced diabetic liver tissues. Furthermore, principal component analysis followed by linear discriminant analysis (PC-LDA) has been used to classify the autofluorescence emission spectra from the control and the experimental group of diabetic rats. The results of this study raise the important possibility that fluorescence spectroscopy in conjunction with multivariate statistical analysis has tremendous potential for monitoring or potentially predicting responses to therapy.
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    Self-blood letting in congestive cardiac failure
    (INTERNATIONAL JOURNAL OF CARDIOLOGY, 2007) Krishnakumar, N; Hankrishnan, S; Tharakan, JM
    A 33-year-old male with idiopathic restrictive cardiomyopathy had dilated and tortuous veins over both lower limbs and over the scrotum with multiple hyperpigmented scars. He was in the habit of puncturing the veins to let out blood during episodes of worsening of dyspnoea, thereby relieving dyspnoea by decreasing the preload. (c) 2005 Elsevier Ireland Ltd. All rights reserved.