Iranian Journal of Basic Medical Sciences
Year:2000 | Volume:3 | Issue:1 (6)|Papers Count:9

Employment of nuclear power as a main source, of energy and ever increasing application of radioisotopes in medicine and industry have increased the importance of ionizing radiation studies. Environmental γ radiation is one of the natural radiation components. In this research γ radiation levels have been measured for some stations in Azarbayjan. One of the major aims of this research was to determine the base line for γ radiation at the regions of interest and to recognize the effective factors. In this study, the dose rate due to environmental γ radiation in open air and one meter above the ground level was measured with RDS-110 Survey Meter. The average dose rates for Tabriz, Orumiyeh, Sarein, Iran-Turkey border line, Iran –Armanestan border line and Koojonogh village were 114, 114,164, 86, 66 and 260 nSv/h respectively. These results could be utilized to assess any change at the level of environmental y radiation in future due to geological phenomena or establishment of nuclear power stations in the regions of interest.    

The gene grmA of Bacillus megaterium ATCC 12872 encodes a protein responsible for early spore germination events. In order to determine whether a homologuous of the grmA is present in B. cereus chromosome, a PCR cloning strategy with degenerate primers was exploited. The amplicon with the expected size was purified, cloned into two different B. subtilis integrational vectors, and sequenced. Analysis of the cloned DNA using tBLASTn revealed high homology to B. magaterium grmA. This is the first report of identification of a grmA homologue in B. cereus. We suggest that grmA genes family has a common function in spore germination of both B. megaterium and B. cereus. It would be interesting to investigate the role of an antiporter in the complicated process of spore germination.    

It is clear that thyroid hormones are required for the normal development of brain and without them, the protein synthesis, myelinogenesis and axonal ramification decrease. In order to investigate the effects of maternal hypothyroidism and thyroxine therapy during Pregnancy and lactation on learning abilities of offsprings of hypothyroid mothers, twelve virgin Wistar rats were chemically thyroidectomized by 500 mg/lit propylthiouracil (PTU) dissolved in drinking water. After mating, thyroidectomized rats were randomly divided in three experimental groups 1, 2 and 3 and were treated, respectively, as follows; PTU during pregnancy and lactation; PTU+ 1mg/lit L-thyroxine during pregnancy and PTU+ 1mg/lit L-thyroxine during pregnancy and lactation. After delivery, from each litter, one male and one female offspring were randomly selected and were examined in a T-complex maze and their learning behaviour was measured by the number of errors and the time of reaching the goal. The results indicate that thyroxine therapy improves the learning abilities of offsprings specially in experimental group 3, which may be a reflect of thyroxine therapy effects on developmental processes of the nervous system.      

Matrix based controlled release tablets of Isosorbide Dinitrate (ISDN) were formulated using insoluble polymer of Methacrylic acid copolymer (Eudragits) and swellable polymers of Hydroxypropyl methylcellulose (HPMC) and Carbomer. The effect of those polymers on the release rate of relatively hydrophobic drug of ISDN were investigated. The drug release from basic types of formulations and two brand products of Isoket and Arya ISDN tablets were studied and evaluated. Both Methocel and Eudragit matrices were found to provide tablets with good qualities. The  dissolution data also indicated that it was possible to prepare a dosage form from Eudragit NE30D polymer capable of delivering the drug at constant rate.      

Sport medicine researchers have recently paid attention to positive and negative effects of physical activities on the immune system. It has been shown that moderate and regular moderate and regular exercise increases some aspects of immune system functions in general. In contrast, intensive exercise can result in inflammatory responses of the immunological system and acute or chronic damage of the immune system in athletes. The aim of this study was to evaluate the effects of eccentric exercise on T lymphocyte sub - populations, IL-6, CPK and LDH concentration in female athletes twelve female athletes (mean age 21±0.75 years, mean weight 57±5.34kg and mean height 162±2.71cm) were selected to participate in this study. Subjects performed a 13 minutes eccentric Exercise with pacing on treadmill according to Ellestad protocol. Blood samples were collected before, immediately after, one and two hours after exercise. Absolute numbers of T lymphocyte sub - populations including: CD4+, CD8+, CD3+ , CD56+(NKC) and the ratio of CD4+/CD8+ were determined in blood samples using flowcytometry and IL-6 concentration was determined using ELISA . The results showed that, absolute numbers of CD4+, CD3+, CD8+, CD56+(NKC) increased Significantly immediately after exercise and decreased significantly after one hour compared to the resting status levels. IL-6 concentrations showed significant increase after eccentric exercise. The concentration of CPK and LDH in serum increased significantly immediately after exercise and returned to normal level one hour after exercise. Our results indicated that short term but heavy exercise can temporary suppress the immune system. This effect will increase individuals susceptibility to pathogens in long term.      

Biofilm formation is a major problem in different industrial fields; including pharmaceutical, agricultural and medicinal industries. It is possible to select materials for making containers with lowest probability of biofilm formation. In this study, the biofilm formation on the glass, plastic and some other materials, at 2, 6 and 10 days intervals, in nutrient broth medium, already inoculated with Bacillus subtilis, was investigated. Different temperatures for biofilm formation were used. Also glycocalyx, developed by biofilm formation, quantitatively determined using a biochemical method. The results showed that biofilm formation was maximum at 30°C. Total counts of bacteria detached from biofilm, indicates that, it can develop biofilm on the polypropylene surface much more than the other surfaces and after 10 days, the formation of biofilm reached to its maximum level. Also surfaces with similar physical properties had no difference on biofilm formation while surfaces with different physical properties showed 10-20 times difference on biofilm formation. Quantitative determination of glycocalyx showed that, by increasing the time, the glycocalyx formation was increased and the yield was more on polypropylene surface and less on glass. The results of this study could be used in selecting the material for pharmaceutical containers.      

One of the most allergenic pollen in the world is related to Chenopodium family. As the antigenic and allergenic variation among different regional species have been reported, in the present study the pollen grains were collected from the flowering Chenopodium album of Karaj region. Highly pure pollen (>95 %) was dried, defatted, and then aqueous extract was prepared. As the most allergens are proteins or glycoproteins with molecular weights of 5-75kDa, the crude extract was ultrafiltered. SDS-PAGE was performed to characterize and compare various allergenic extracts with commercial allergens. Crossed Immunoelecterophoresis was carried out to study the number of antigenic components of crude allergenic extract using rabbit anti-allergen antibodies. Considering the results of in-vitro and in-vivo experiments on Ch. album extract, more research is suggested to evaluate the usefulness of this product in diagnostic and therapeutic purposes.      

Grass pollen is one of the major causes of worldwide-allergy. Saffron (Crocus sativus) is a monocotyledon plant that belongs to the family of Iridiaceae. Saffron is a native plant of Iran which is cultivated widely in the central and southern parts of Khorassan in Iran. In this study, allergenicity of saffron pollen and pistil was investigated. The results for saffron pistil within 234 subjects who referred to allergy clinic, showed only positive skin prick test in 3 subjects. On the other hand, in 267 subjects (referred to allergy clinic) 47 subjects showed positive skin prick test to saffron's pollen. 79% of subjects, who had positive skin prick test, have rhinitis. Other symptoms including asthma, urticaria and persistent cough were seen.