فهرست مطالب عبدالرحیم آبسالان

Anthropogenic pollutants are known to have adverse effect on ecosystem, and human health. Biodegradation is an option that has been widely used to remediate organic contaminants and reduce the risk of these hazardous materials. Microorganisms are readily available to screen and can be rapidly characterized to be applied in many extreme environmental conditions. Actinomycetes have a great potential for the production of bioactive secondary metabolites which have biodegradation activity. This study aimed to screen and characterize Nocardia species with biodegradation potential from diverse Iranian ecosystems. The isolates were screened from 90 collected environmental samples, identified and characterized using conventional and molecular microbiological methods including the PCR amplification and sequencing analysis of 16S rRNA and rpoB genetic markers. Growth rate in presence of pollutants, chromatography, Gibbs and turbidometric methods were used to determine bioremediation ability. A total of 19 Nocardia isolates were recovered from the cultured samples (21.1%) that belonged to 10 various species. The most prevalent species was N. farcinica; 4 isolate (21%), followed by N. cyriacigeorgica and N. cashijiensis; 3 isolates each (15.7%) and N. asteroides 2 isolates (10.5%). In this study isolates showed biodegradation activity against PAHs, phenol and oil derivations. Discussion and Our results showed that various Nocardia species isolated from Iranian ecosystems have great potential for biodegradation of environmental contaminant, therefore we can used this bacteria in bioremediation process, although they have not received much attention for such significant usage.

Tertiary (3D) structure determination using X-ray diffraction crystallography is a time consuming method, needs special facilities and expert operators. 3D structure determination by bioinformatics software is worth in experimental research, especially for drug discovery purposes and evolutionary relationships. Using computational biology software and databases, we have determined probable 3D structure of human voltage-gated sodium ion channels (VGSCs) and their developmental associations.
Amino acid sequences of VGSCs were obtained from Uniprot and used to predict their 3D structure using SWISS-MODEL server and by its definitive algorithm for protein basic local alignment search tool (BLAST)-(followed by visualization using Molegro Virtual Viewer software). Phylogenic tree was plotted using Mega 5 application for VGSCs sequences. VGSCs interactions were determined by String-db server.
According to the Neuron data-base, there are 9 types of human VGSCs named SCN1A-5A and SCN8A-11A. SWISS-MODEL software was just only able to predict some domains of VGSCs with high identity percentages. The identity percentages were variable for each VGSC and varied from 16.57% (SCN4A) to 100% (SCN2A, SCN5A). Blast results and drawing phylogenetic trees practice showed that animals, such as chimpanzee, gibbon, and gorilla have the most similar protein sequences.
In most cases, modeling using SWISS-MODEL is not enough decisive for prediction of protein 3D structure. Thus, we propose that researchers use mentioned animals for experiments of VGSCs, characterized structures for bioinformatics and drug designing surveys. In this case, the results of animal trials could be generalized to human more precisely.

Myocardial infarction as a leading cause of death in most populations is associated with blood clot formation in coronary artery, and rapid clot lysis is important for patient treatment. Some reports have indicated the effects of some trace elements on blood coagulation and clot lysis. The aim of this study was to evaluate the effects of zinc, copper and aluminum on in-vitro coagulation and clot lysis by streptokinase.

The citrated fasting fresh-pooled plasma prepared from healthy individuals was divided to zinc, copper, aluminum and control groups. Calcium chloride and streptokinase were used for induction of plasma coagulation and Fibrinolysis, respectively. Clot formation and lysis were monitored turbidimetrically, and quantitative parameters including lag time for coagulation, clot lysis, time of coagulation and time for half lysis were calculated after plotting a kinetic curve of time versus absorbance. SPSS software and independent t-test were used for statistical analysis.

In comparison with control, addition of zinc reduced lag time of coagulation(216.8±4.4 vs 229.2±2.6 sec, P= 0.001) and copper reduced coagulation time(194.4±3.7 vs 280±3.5 sec, P= 0.001). Addition of aluminum increased lag time for coagulation(563.6±8.8 Sec, P= 0.001), lag time for clot lysis(194±3.6 sec, P= 0.001), coagulation time(484±7 sec, P= 0.001), and time for half lysis of clot (328.4±6.1 sec, P=0.001).

Results indicated that essential trace elements including zinc and copper at low levels do not have important effects on coagulation and fibrinolysis, but aluminum as a toxic element affects these processes and partially inhibits them even at very low levels.

Infected surfaces are a means of transporting infection, especially in health-care centers. Thus an appropriate sterilization method can help controlling hospital infection. In this study the antibacterial effect of Hydrogen peroxide and silver ions composition (H2O2 + Ag+) on growth inhibition of Escherichia Coli as well as Proteus Mirabilis and Klebsiella Pneumonia on a steel surface were tested. Initially we sterilized each 10-part bacterium, overall 30 steel surfaces using alcohol and fire. Then we contaminated the surfaces with a heavy suspension of aforementioned bacteria and contacted the H2O2+Ag+ solution (concentrations were 30 ppm ad 30 ppb respectively). After each step, bacterial cultures were performed on Eosin Methylen Blue (EMB) agar. Cultures were interpreted using Mc Nemar analysis method in 37O C after 24 h. Statistical analysis showed a significant difference before and after performing H2O2+ Ag+ solution (P= 0.008 for E.coli, P=0.014 for Klebsiella, P=0.002 for Proteus). Previous studies focused mostly on Hydrogen peroxide vapor disinfection, but here we indicated its effect as a surface disinfectant in the form of solution and composition with silver, a heavy metal with antibacterial property. Our future objective is to evaluate the effect of such disinfectant in hospital and health-care centers that is underway.

β thalassaemia is an inherited blood disorder that needs repeated blood transfusions. Serum lipid abnormalities have been repeatedly reported in these patients. Although thalassemia is common in some regions of Iran, there is little evidence on serum lipids and lipoproteins profile in these patients.�The aim of this study was to evaluate plasma lipids and lipoproteins in thalassemic patients referring to Yazd Blood Transfusion Center. In this cross-sectional case-control study, serum lipids, lipoproteins and lipoprotein(a) from 58 patients (32 females, 26 males) with β thalassemia major, were compared to 68 (40 females, 28 males) age matched healthy control. Blood samples were taken after at least 12 hours fasting and before the patient's blood transfusion. Total cholesterol (TC), triglycerides (TG), and high-density lipoprotein-cholesterol (HDL-C), were determined enzymatically using laboratory test kits. Lipoprotein (a) assay was done by electro-immunoassay method. SPSS software (V.11), t-test and U-test were used to compare lipids, lipoprotein, and lipoprotein (a) and Pearson correlation test was used to determine the correlation between variables. β thalassemic patients had significantly lower TC, HDL-C and LDL-C values compared to the control (113.8±17.7, 32.3±8, 58.2±14.7 vs 158.3±30.6, 43.8±9.2, 96.2±26.4, p<0.001), while serum TG and lipoprotein(a) levels had no significance difference in two groups. Nineteen percents of patients and 27% of controls had serum lipoprotein (a) levels equal to or higher than 30 mg/dl. There was no significant correlation between lipids, lipoproteins and age in two groups, however in control group a significant correlation was seen (r = 0.5, p < 0.001). The results indicate that in patients with β thalassemia major, cholesterol and its carrier lipoproteins are lower than those in the healthy controls, but triglycerides and lipoprotein (a) have no significant difference. It seems that endocrine disorders in patients with β thalassemia has more effects on serum lipid profile. Further studies are needed to clarify the exact effect of different conditions on lipid profile in thalassemic patients.