Iranian Journal of Basic Medical Sciences
Volume:10 Issue: 4, Winter 2008

The aim of this study was to compare the sensitivity and specificity of Acid fast and Auramine-Rhodamine staining and Multiplex PCR for the detection of Mycobacterium tuberculosiscomplex and non tuberculosis Mycobacteria on formalin fixed paraffin embedded tissues (FFPE).Forty cases of FFPE pleural and bronchial tissue with chronic granulomatous inflammation and caseous necrosis and 10 cases with bronchogenic carcinoma as controls were investigated. We designed a Multiplex PCR DNA amplification method with two targets: 123bp DNA fragment from IS6110, which is present only in mycobacterium tuberculosis complex and 162bp DNA encoding Ag 85complex which is present in all of mycobacteria. The FFPE also stained by Acid fast and Rhodamine-Auramine staining method.In 26 samples (65%) 123 bp and 162 bp DNA fragments were detected together (12 in bronchial samples and 14 in pleural samples).The 162 bp fragment wasn''t detected alone. The sensitivity of PCR was 65% and the specificity was 100%. Eleven cases were positive for Acid fast staining. There was 27.5% sensitivity and 100% specificity. Thirteen cases were positive for Auramine-Rhodamine staining (A-R-S); there was 32.5% sensitivity and 100% specificity. All of the 10 controls were negative for 123 bp, 162 bp DNA fragments, for Acid fast and Auramine-Rhodamine staining.Multiplex PCR is a sensitive, specific and rapid method for detection of M. tuberculosis in FFPE tissues.

High concentration of iron and other trace elements could restrict bacterial growth and modify their metabolic pattern as well. However, this study aimed to find out the influence of iron, chromium, cadmium and synergism or antagonism between these elements on the growth of a gram positive bacterium. In a series of experiments, Bucillus cereus was cultured in a nutrient broth which supplemented with Fe+2, Fe+3, Cr+3, Cd+2 separately, or in combination with each other, at 37° C for 5 hours. Bacterial growth was measured every half – hour, using spectrophotometer.The results indicated that bacterial growth rate reduced in the presence of 0.5 mM/L concentration of Fe+2 or Fe+3, in comparison with control and the growth of bacteria was inhibited by 1 mM/L concentration of iron. The results also revealed that Fe (III) as well as Fe (II) was toxic for bacteria. Chromium had partial inhibitory effects on the growth of bacteria and cadmium was very toxic. Cr+3 and Cd+ had antagonistic effect with iron on the growth of bacteria. Data obtained here provide a potentially interesting conceptual advance in toxic effects of trace elements on pathogenic bacteria.

This study was initiated to investigate the effect of Portulaca oleraceae on morphine dependence in mice.Dependence was induced using the subcutaneous injections of morphine for 3 days. On the day 4, morphine injected 2 h prior to intraperitoneal injection of naloxone. The plant extracts ethanolic or aqueous administered 0.5 h before the final dose of morphine. The number of jumping during the 30 min period after naloxone injection was considered as a measure of withdrawal syndrome. Both extracts reduced the jumping episodes dose-dependently. The maximum effect was observed at doses of 0.28 g/kg and 1.4 g/kg for the aqueous and ethanolic extracts, respectively. Clonidine and extracts decreased the total activity in locomotion test.These findings indicated that Portulacea oleraceae extracts can decrease morphine dependence in mice.

Mycophenolate mofetil (MMF) is commonly administered concomitantly with ganciclovir for managing transplant recipients who infected with CMV. This study was conducted to evaluate the probable effects of ganciclovir on Mycophenolic acid (MPA) pharmacokinetic.Ten kidney transplant recipients who full field inclusion and exclusion criterias enrolled in this study. The first full profile blood sampling was taken during the combination therapy of gancyclovir and MMF. The second sampling was taken one week after discontinuation of gancyclovir. Serum concentrations of MPA and its glucuronide metabolite (MPAG) were determined by high-performance liquid chromatography (HPLC) method. The pharmacokinetic parameters of MPA were measured, in two conditions, for each patient. There was no significant differencebetween MPA clearance alone and in combination with ganciclovir (28.2±21.9 L/hvs 31.9±21.3 L/h, p=0.207) and also no significant difference was seen between the MPA Area Under the Curve (AUC) in two conditions (43.48±16.27 µg/ml.h vs 39.80±20.18 µg/ml.h, p=0.221). MPAG AUC was increased significantly when the drugs were administrated in combination (957.8±675.2 µg/ml.h vs 1348.6±1095.1µg/ml.h, p=0.036). Also ganciclovir induced entrohepatic recirculation of MPA in two patients. The pharmacokinetic parameter of MPA was not affected by ganciclovir. But ganciclovir increased MPAG AUC and induced enterohepatic recirculation of MPA.

The extensive pollution of natural ecosystems has occurred by organophosphorus pesticides, being used for improvement of crop production in agriculture. Biodegradation is interested in application of multifunctional bacteria containing genetical elements which specially degrade organophosphorus compounds. In this paper the detection of two bacteria species, Pseudomonas and Flavobacterium, which harbouring organophosphorus degrading elements from environmental samples is reported.Several resistant strains isolated from different cultures that previously were cultivated with related sources such as soils and waters. These bacteria had been isolated from organophosphorus enriched mineral solutions, and following inoculation, visible colonies were observed on mineral and MacConkey’s agar medium. The resistant bacteria were identified by conventional procedures and monitored with certain properties like stability, tolerance, resistance to organophosphorus compounds and different antibiotics. The genetical elements for organophosphate degradation were confirmed by adding acridine orange to culture of resistant strains which could delete these capabilities. Fifty strains were optimally grown in presence of three classes of organophophoruses like guthion, dimethoate and methyl parathion with concentrations of 2.5, 4, and 8 gl-1 respectively. The gram-negative bacteria were identified using conventional diagnostic procedures, asPseudomonas and Flavobacterium species. These strains were harbouring organophosphorus degrading elements which were deleted by acridine orange as mutagen. Also, most of these bacteria were resistant to different antibiotics that used as biomarkers in discrimination of sensitive strains to organophosphoruses.The genetical elements such as resistance to organophosphoruses and antibiotics were transferred to the sensitive bacteria by matting technique and cured as multifunctional organisms which had high capability for various organophosphoruses. The multi-degrading strains might be suggested as useful tools for detoxification of harmful organophosphoruses in agriculture.

Cerebrospinal fluid (CSF), its secretion, circulation and absorption have been the subject of recent researches. There is a general agreement that the main site of CSF secretion is in the choroids plexus. However, the main absorption site is controversial. Some believe that arachnoid granulations are the principle sites of CSF absorption. In this study, different locations of CSF absorption in cats are investigated. 2 ml (100 mg), of ferrous dextran was injected into the subarachnoid compartment of seven cats. After 15 days the animals were euthanized, and the central nervous system (CNS) and its relative tissues were analyzed for any iron amlumulation. Several tissue samples were taken and stained with Prussian blue and Hematoxylin-eosin.The light microscopic study of different tissues showed amlumulation of the tracer in olfactory and optic nerves, dorsal root ganglia as well as spinal nerve roots.The main locations of CSF absorption were the spinal nerve roots and their surrounding lymphatic tissue. There is reason to believe that some endothelial fenestrate within these roots were involved in this process.

Bacterial adhesion is governed by specific and nonspecific interactions such as hydrophobicity. Hydrophobic interactions play a role in the adherence of microorganisms to a wide variety of surfaces and facilitate biofilm formation due to bacterial adhesion. In this article the relation between cell surface hydrophobicity and antibiotic resistance was studied.We studied antibiotic susceptibility of isolated Streptococci from dental plaque and caries (by disk diffusion method) and cell suface hydrophobicity (by microbial adhesion to hydrocarbon).The results indicated that the mean surface hydrophobicity of all mutans and other than mutans Streptococci, without considering their location (caries or plaque) showed significant differences (mean 78%, 59%, respectively). No significant differences among caries and plaque isolated Streptococci were found regarding the antibiotic susceptibility. Chi square test with contingency table showed significant qualitative correlation between classes of hydrophobicity (high, moderate and low) and antibiotic resistance (p= 0.001), but according to the regression models we could not find any linear correlation between cell surface hydrophobicity and the diameter of inhibition zone for each antibiotic separately.The high overall proportion of hydrophobic bacteria found in this study suggests that cell- surface hydrophobicity may play a role in adherence of certain oral species to the tooth surface. If bacteria attach to surfaces and form biofilm they can be more resistant, but these two factors (antibiotic resistance and cell surface hydrophobicity) did not show a linear correlation in this study.