tailieunhanh - PERIPHERAL BLOOD BASED C-PCR ASSAY FOR DIAGNOSING EXTRA-PULMONARY TUBERCULOSIS

The developed technique involves contrast enhancement using sequentially iterative smoothing filters, histogram equalization, and simultaneous application of two types of edge detection processes namely, maximum-difference edge detection [3] and Canny’s edge detection [4]. The post processed image is combined with the original image to accentuate the edges while eliminating noise. Smoothing is implemented because of its effect to reduce specific types of noise signals in the digitized image. However, singular application of smoothing filter does not always provide beneficial results, especially if it is applied to noisy images that are characterized by considerably low signal-to noise ratio. Hence, we proposed an iterative smoothing filter that apply the filter repetitively and obtain series of results for assessment | Indian Journal of Experimental Biology Vol. 47 June 2009 pp. 447-453 Peripheral blood based C-PCR assay for diagnosing extra-pulmonary tuberculosis Rajiv Khosla1a Alka Dwivedi1b B C Sarin2 P K Sehajpal1 1 Department of Molecular Biology and Biochemistry Guru Nanak Dev University Amritsar 143 005 India Department of Tuberculosis and Chest Diseases Sri Guru Ram Das Institute of Medical Sciences and Research Amritsar 143 005 India Received 8 February 2009 Extra pulmonary tuberculosis EPTB constitutes around 20 of all tuberculosis cases in India. Conventional methods are of limited use in diagnosing this form of the disease. Polymerase chain reaction PCR has emerged as a sensitive and specific tool for documenting the presence of Mycobacterium tuberculosis in clinical samples but lacks quantitative ability. The present study evaluates peripheral blood as an alternative clinical specimen for diagnosing EPTB. Peripheral blood samples from 38 EPTB and 89 non tuberculous subjects were analyzed for the presence of tubercle bacilli by MPB 64 gene based PCR method. The assay gave an overall sensitivity of with negative predictive value of which is superior to present gold standard of mycobacterial culture and . Additionally of non tuberculous subjects gave positive results with the PCR thus mitigating the clinical utility of this test. An in-house Competitive PCR C-PCR assay was used to determine the mycobacterial load in peripheral blood from culture positive culture negative EPTB patients and non tuberculous controls which ranged from 7498 - 12498 602 - 4797 and 101 - 800 genome equivalent ge mL respectively. The data clearly demonstrated that C-PCR assay can furnish insightful information in diagnosing extra pulmonary disease. Keywords Competitive PCR Extra-pulmonary tuberculosis Mycobacterium tuberculosis PCR Incidence of extra pulmonary tuberculosis EPTB is on the increase world over and the same is higher in Asians than Caucasian .