Faculty Publications
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Item Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images to reduce storage and transmission overheads. The text data are encrypted before interleaving with images to ensure greater security. The graphical signals are compressed and subsequently interleaved with the image. Differential pulse-code-modulation and adaptive-delta-modulation techniques are employed for data compression, and encryption and results are tabulated for a specific example.(Compact storage of medical images with patient information) Acharya, A.U.; Anand, D.; P, S.B.; C, N.U.2001Item Automated identification of diabetic retinopathy stages using digital fundus images(2008) Nayak, J.; Subbanna Bhat, P.S.; Acharya, R.; Lim, C.M.; Kagathi, M.Diabetic retinopathy (DR) is caused by damage to the small blood vessels of the retina in the posterior part of the eye of the diabetic patient. The main stages of diabetic retinopathy are non-proliferate diabetes retinopathy (NPDR) and proliferate diabetes retinopathy (PDR). The retinal fundus photographs are widely used in the diagnosis and treatment of various eye diseases in clinics. It is also one of the main resources for mass screening of diabetic retinopathy. In this work, we have proposed a computer-based approach for the detection of diabetic retinopathy stage using fundus images. Image preprocessing, morphological processing techniques and texture analysis methods are applied on the fundus images to detect the features such as area of hard exudates, area of the blood vessels and the contrast. Our protocol uses total of 140 subjects consisting of two stages of DR and normal. Our extracted features are statistically significant (p<0.0001) with distinct mean±SD as shown in Table 1. These features are then used as an input to the artificial neural network (ANN) for an automatic classification. The detection results are validated by comparing it with expert ophthalmologists. We demonstrated a classification accuracy of 93%, sensitivity of 90% and specificity of 100%. © 2007 Springer Science+Business Media, LLC.Item Particle deposition in human respiratory system: Deposition of concentrated hygroscopic aerosols(2009) Varghese, S.K.; Gangamma, S.In the nearly saturated human respiratory tract, the presence of water-soluble substances in the inhaled aerosols can cause change in the size distribution of the particles. This consequently alters the lung deposition profiles of the inhaled airborne particles. Similarly, the presence of high concentration of hygroscopic aerosols also affects the water vapor and temperature profiles in the respiratory tract. A model is presented to analyze these effects in human respiratory system. The model solves simultaneously the heat and mass transfer equations to determine the size evolution of respirable particles and gas-phase properties within human respiratory tract. First, the model predictions for nonhygroscopic aerosols are compared with experimental results. The model results are compared with experimental results of sodium chloride particles. The model reproduces the major features of the experimental data. The water vapor profile is significantly modified only when a high concentration of particles is present. The model is used to study the effect of equilibrium assumptions on particle deposition. Simulations show that an infinite dilution solution assumption to calculate the saturation equilibrium over droplet could induce errors in estimating particle growth. This error is significant in the case of particles of size greater than 1 ?m and at number concentrations higher than 105/cm3. © 2009 Informa UK Ltd.Item Microbial transformation of bioactive natural products(2010) Gopkumar, P.; Mugeraya, G.In the present study, the fungal biotransformation of 1, 2, 3, 9-tetra hydrpyrrolo [2, 1-b] quinazolin-3-ol (I) is presented. Biocatalysis, isolation and subsequent structure elucidation of the newly transformed metabolite (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) is presented. Microbial transformation of Vasicine (I) by Aspergillus niger, Rhizopus arrhizus, Pencillium notatum and Trematus versicolor afforded (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) (100%) as the sole metabolic product. 1, 2, 3, 9-tetra hydrpyrrolo [2, 1-b] quinazolin-3-ol (I) and (-)-3-hydroxy -2, 3-dihydro pyrrolo [2, 1-b] quinazoline-9(1H)-one (II) screened for antibacterial and antifungal activity.Item Synthesis, chemical characterization of novel 1,3-dimethyl acridones as cytotoxic agents, and their DNA-binding studies(2010) Sathish, N.K.; Gopkumar, P.; Rajendra Prasad, V.V.S.; Shanta Kumar, S.M.; Mayur, Y.C.A series of new 1,3-dimethyl acridone derivatives were synthesized with different alkyl side chain (propyl and butyl) substitution at N 10-position and highly basic amine groups at terminal end of alkyl side chain. All the synthesized molecules were screened for their cytotoxic activity against human breast adenocarcinoma (MCF-7) and human promyelocytic leukemia (HL-60) cell lines. DNA binding constants (Ki) of selected compounds were determined with calf-thymus DNA. Results showed that the molecules 7, 8, 10, 11, 12, 13, 14, and 15 exhibited good cytotoxic activity with IC50 value <10 ?M. Compound 14 having (?- hydroxyethyl) piperazine butyl side chain exhibited potent cytotoxic activity against MCF-7 cell line and DNA-intercalating properties. Examination of the relationship between lipophilicity and acridone derivatives showed poor correlation. © Birkhäuser Boston 2009.Item Synthesis, characterization and in vitro cytotoxic properties of some new Schiff and Mannich bases in Hep G2 cells(Birkhauser Boston, 2011) Dhanya, D.; Isloor, A.M.; Shetty, P.; Chandrakantha, B.; Satyamoorthy, K.A series of 5-substituted-4-amino-3-mercapto- 1,2,4-triazoles were synthesized and were treated with various 3-substituted pyrazole aldehydes to obtain a series of new Schiff bases (3a-l). Few of the selected Schiff bases were converted into Mannich bases by reaction with diphenylamine/morpholine in presence of formaldehyde in ethanol media (4a-e, 5a-e). These newly synthesized compounds were characterized by elemental analysis, IR, NMR and mass spectrometry studies. A comparative study on the cytotoxic activities of few selected Schiff and Mannich bases was done in HepG2 cells using MTT assay. Few of the screened Schiff bases, 3a, 3d, 3e, 3g and 3h showed dose dependent cytotoxic activity, 3a being the most potent with an IC50 value of 0.018 g/l comparable to the standard drug doxorubicin. Among the Mannich bases, 5b was the most active with an IC50 value of 0.034 g/l. The Schiff bases were found to be more active, when compared to Mannich bases derived from them. The morpholine derived Mannich bases were more potent than those obtained from diphenyl amine. © Springer Science+Business Media, LLC 2010.Item Item Reproductive health financing in Kenya: An analysis of national commitments, donor assistance, and the resources tracking process(Elsevier Ltd, 2013) Sidze, E.M.; Pradhan, J.; Beekink, E.; Maina, T.M.; Maina, B.W.Understanding the flow of resources at the country level to reproductive health is essential for effective financing of this key component of health. This paper gives a comprehensive picture of the allocation of resources for reproductive health in Kenya and the challenges faced in the resource-tracking process. Data are drawn from Kenyan budget estimates, reproductive health accounts, and the Resource Flows Project database and compare budgets and spending in 2005-06 with 2009-10. Despite policies and programmes in place since 1994, services for family planning, maternity care and infant and child health face serious challenges. As regards health financing, the government spends less than the average in sub-Saharan Africa, while donor assistance and out-of-pocket expenditure for health are high. Donor assistance to Kenya has increased over the years, but the percentage of funds devoted to reproductive health is lower than it was in 2005. We recommend an increase in the budget and spending for reproductive health in order to achieve MDG targets on maternal mortality and universal access to reproductive health in Kenya. Safety nets for the poor are also needed to reduce the burden of spending by households. Lastly, we recommend the generation of more comprehensive reproductive health accounts on a regular basis. © 2013 Reproductive Health Matters.Item Synthesis, characterization, anticancer, and antioxidant activity of some new thiazolidin-4-ones in MCF-7 cells(2013) Isloor, A.M.; Dhanya, D.; Shetty, P.; Malladi, S.; Pai, K.S.R.; Maliyakkal, N.There are limited studies centring on the potential of thiazolidin-4-ones as anticancer agents. In this study, a new series of 2-(3-substituted-1H- pyrazol-4-yl)-3-(3-substituted-5-sulfanyl-1,2,4-triazol-4-yl)-1, 3-thiazolidin-4-one (4a-o) have been synthesized by cyclo-condensation reaction of 5-substituted-4-[(3-substituted-1H-pyrazol-4-ylmethylidene)amino]-2H-1,2,4- triazole-3-thione (3a-o) and thioglycolic acid. The structures of all the synthesized compounds were confirmed by elemental analysis, spectral techniques like IR, 1H NMR, and mass spectroscopy. Few compounds exhibited dose-dependent cytotoxic effect in MTT assay in human breast cancer (MCF-7) cells. Apoptotic degradation of DNA due to action of potent thiazolidin-4-ones was analysed by agarose gel electrophoresis and visualized by ethidium bromide staining (comet assay). A concentration-dependent increase in tail length and olive tail moment was observed when treated with thiazolidin-4-ones. In vitro antioxidant studies like DPPH and ABTS-free radical scavenging assays-indicated moderate activity of thiazolidin-4-ones. © 2012 Springer Science+Business Media, LLC.