ABSTRACT
INTRODUCTION: Tuberculosis is a major public health threat, annually affecting new individuals worldwide, especially those in developing countries. Rapid detection of the agent and effective treatment are two important factors in controlling this disease. METHODOLOGY: The present study aimed to evaluate polymerase chain reaction (PCR) as a rapid and direct molecular method for the diagnosis of Mycobacterium tuberculosis (MTB) in 70 clinical specimens (62 sputum samples, six cerebrospinal fluids, and two biopsies) using heat shock protein (hsp65) as the gene target. Automated sequencing of the same gene was used for the identification of MTB to the species level. RESULTS: The sensitivity of PCR was 81.13%, with specificity of 88.24%; the positive and negative predictive values were 95.56% and 60%, respectively. CONCLUSION: Based on these results, the hsp65 gene sequence can be used to differentiate the members of MTB complex from non-tuberculosis mycobacteria (NTM).
Subject(s)
Bacterial Proteins/genetics , Chaperonin 60/genetics , Mycobacterium tuberculosis/isolation & purification , Polymerase Chain Reaction/methods , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Spinal/diagnosis , Bacterial Proteins/chemistry , Base Sequence , Cerebrospinal Fluid/microbiology , Chaperonin 60/chemistry , Humans , Molecular Sequence Data , Morocco , Mycobacterium tuberculosis/classification , Mycobacterium tuberculosis/genetics , Predictive Value of Tests , Sensitivity and Specificity , Sequence Analysis, DNA , Sputum/microbiology , Tuberculosis, Pulmonary/microbiology , Tuberculosis, Spinal/microbiologyABSTRACT
Structure-cytotoxicity relationships were studied for a series of 90 HEPT derivatives by means of multiple linear regression (MLR) and artificial neural network (ANN) techniques. The values of log(1/CC50) (CC50=cytotoxic dose of compound required to reduce the proliferation of normal uninfected MT-4 cells by 50%) of the studied compounds were correlated with the descriptors encoding the chemical structures. Using the pertinent descriptors revealed by the regression analysis, a correlation coefficient of 0.935 ( s=0.149) for the training set ( n=81) was obtained for the ANN model with a 5-6-1 configuration. The results obtained from this study indicate that the cytotoxicity of HEPT derivatives is strongly dependent on hydrophobic factors, mainly log P(R1), and dependent on the steric factors, especially SigmaMW(R3+R4). Comparison of the descriptors' contribution obtained in MLR and ANN analysis shows that the contribution of some of the descriptors to cytotoxicity may be non-linear.
Subject(s)
Anti-HIV Agents/chemistry , Anti-HIV Agents/toxicity , Reverse Transcriptase Inhibitors/chemistry , Reverse Transcriptase Inhibitors/toxicity , Thymine/analogs & derivatives , Thymine/chemistry , Thymine/toxicity , Animals , Cell Line , Cell Survival/drug effects , Linear Models , Neural Networks, Computer , Structure-Activity RelationshipABSTRACT
Structure-toxicity relationships were studied for a set of 47 insecticides by means of multiple linear regression (MLR) and artificial neural network (ANN). A model with three descriptors, including shape surface [S(R2)], hydrogen-bonding acceptors [HBA(R2)] and molar refraction [MR(R1)], showed good statistics both in the regression (r = 0.875, s = 0.417 and q2 = 0.675) and artificial neural network model with a configuration of [3-5-1] (r = 0.966, s = 0.200 and q2 = 0.647). The statistics for the prediction on toxicity [log LD50 (lethal dose 50, oral, rat)] in the test set of 20 organophosphorus insecticides derivatives is (r = 0.849, s = 0.435) and (r = 0.748, s = 0.576) for MLR and ANN respectively. The model descriptors indicate the importance of molar refraction and shape contributions toward toxicity of organophosphorus insecticides derivatives used in this study. This information is pertinent to the further design of new insecticides.
