IRANIAN JOURNAL OF BIOLOGY
Year:2010 | Volume:22 | Issue:4|Papers Count:20

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Demyelination is a classical feature of MS lesion. Toxic demyelination by ethidium bromide (EB) is one of the most commonly used models for investigating the repairing capacity of the CNS. EB induces focal demyelination in the CNS. The present study investigates contribution of mature oligodendrocyte in remyelination after EB induced demyelination in the brain stem of normal Wistar rats after treatment with bee venom (BV). Bee venom therapy is widely used agaist MS but to undrestand its functions previous studies suggests that the primary allergic components of bee venom histamine and phophplipase A2 induced IL-10 production by Th-2 cells and suppressed T-cell proliferation. Studies suggest that anti-inflammatory and analgesic properties of bee venom are related to modulation of adrenoreceptor activity and serotonergic neurotransmission. In this study thirty male Wistar rats (200-250 gr) were used. The rats were divided into four groups and all (excepte control) had intracisternal injection of 10 days after injection EB and saline intracisternal injection of either 10 ml EB or 0.9% saline as follows in group 2 and 4 receive BV. 9 days after injection EB, removed brainstem and prepared for histotechnicue poccessing and brainstem tissue stained with Luxol fast blue and solochrome cyanine and confirmed local demyelination. 13 days after injection EB followed by bee venom intraperitoneally for 10 days. The animals were anesthetized in 9, 13 and 27day injection and brainstem section were collected and processed for light microscopy. The results of statistic were analyzed by SPSS software (one way ANOVA) and P less than 0.05 were considered as significant. In this study we observed that BV has positive effect on remyelination of the lost myelin axons, this maens that BV can cause decreas inflammatory and improved migration oligodendrocyte progenitor cells in demyelinated areas. More studies are required to determinate immunohistochemectry growth factors in brain stem tissu and CSF in this process.

This study carried out in four months from May to Agust 2006 in fish culture and propagation of bony fish center of Sijaval. Food habit of larvae and fingerlings in eight earthen ponds of 2 ha for each were studied.ponds fertilized with manure, for enrichment of live foods. Sampling of larvae and fingerling were done every two weeks and in each sampling 100 specimens from each pond were taken. Specimens were eriscreated and gut contents were observed under microscope with X40 magnification. Frequency of feeding items in different period of life was determinated. Span such as larvae and fingerling stages were counted.Gut contents in both stages were: daphnia, cyclops, rot, ferns, detritus, concentrated food, chironomid, algae cell muscus of gut, and some partly digested particles which were not indetified. These items were accumulated in the end of intestine. Algae in the gut content were green algae, which had the highest percentage, blue-green algae etc. Situtation of each organisms from the feeding point of veiw in different weight was determinated. In such a way that the organism fed is main food, marginal food, non-selective food. In larvae stage of specimens, rotifer (main food), algae and concentrated food were found in gut content. In fingerling stage detrit and algae were found as main food items. While Cyclops, Daphnia and Chironomid were taken as marginal food.

The most important order of crustacean is decapoda. They have several larval stages which the youngest of them named nauplius. The naupliar development in some of the species of decapods occurs in the embryon and free larvae hatches. Because of the embryonized nauplius, identification of the embryonic developmental stages has been difficult yet and new methods are required to compartment. In this study, we examined using of the Eye Index to identify the embryonic developmental stages of the three species of decapoda i.e. Palaemon elegans, Homarus gammarus and Astacus leptodactylus which have different life histories and inhabit in brackish water, marine and fresh water, respectively. Eye index determines by the method which was innovated by Perkins (1972). Hatching eye index is 156 mm for P. elegans, 430 mm for A. leptodactylus and 640 mm for H. gammarus. The results show that eye index can be used for the determination of the embryonic developmental stages as a simple method. When the eye index receives to the half part of the hatching EI, half part of the developmental process passed. When the EI reaches to the one third of the hatching eye index, one third of the embryonic development passed. Eclosion occurs in the maximum embryonic eye index. So we propose to use the eye index as a useful and easy method to distinguish the successive developmental stages of the embryonized nauplius.

An initial knowledge of range quality is essential for determining Gazella subgutturosa habitat nutritional carrying capacity and sustainable range management, for this aim a study was designed in which changes in forage quality that consumed by gazelle. The study was conducted in Kalmand-Bahadoran protected area, Yazd Province, Food preference was also investigated by direct observation. The result revealed that Stipagrostis plumose, Tecrium polinim, Artemisia siberi, Salsola tomentosa are of the main food preference for Persian gazelle. Protein contents of each consumed plant species was estimated by utilizing Kjeldal method. This study showed that A. siberi has the maximum rate of protein around 11.37 percent. Despite high amount of protein in A. siberi, it could not provide food needed for Gazella subgutturosa.

The rotifer Brachionus calyciflorus is one of the very important zooplankton which lives in freshwater that uses algae, protozoa and bacteria of 1-200 m as food. It will be highly digested in digestive tract of aquatics and the obsorption rate is 97%.Also,its size is smaller than the mouth of aquatics which initiated exogenous feeding where as the highest survival rate was observed in Barbus barbu larvae which consumed Brachionus calyciflorus as the initial food. So, this study investigates on the effects offive different diet treatments including yeast, Chlorella vulgaris , Senedesmus oblquus, (C. vulgaris +S. oblquus) and mixture of (yeast+ C. vulgaris +S. oblquus) on increasing rotifers size. The feeding intensity was 1x106 cells/ml. Water sample was collected from pond no.11 of the Shahid Beheshti hatchery. The rotifers were maintained at stocking density of 50 ind/ml for a period of seven months to acclimatize them to laboratory conditions. Three replicates were used for each treatment. Experiments were carried out in test tubes placed in water baths. The maximum volume of each experimental group was 20 ml and the pH of the medium was 7.6. The density of rotifers in mild aeration was provided and test tubes were exposed to 1000 lux light intensity and 27ºC temperature. The experiment carried out for 10 days .The size of lorica (chitin cover of rotifer) was measured by Biocom visiol software which was connected to camera and Nikon microscope (E-600). The highest difference observed in treatments 1, 2 and 5, 1. The results indicated the most increase in lorica length ,eeg length respeictivly ( 219.2±5.84 m ), (117.9±2.1 m) observed in feeding by Senedesmus oblquus and the least increase in lorica length,eeg length respeictivly (189.6±1.17 m), (111.2±1.17 m) observed in feeding by yeast. In this study, also the lorica area and its egg volume was investigated to determine the relationship between diet and rotifer size and its effect on egg.

Leptospirosis is a worldwide zoonotic disease with a much greater incidence in tropical and temperate regions. It has now been identified as one of the emerging infectious diseases. Since, the incidence of Leptospirosis is significantly high in temperate regions among rice field workers and livestock animals at Mazandaran province, it is neccessery to evaluate condition of Leptospirosis that will help to recognize the most prevalent for vaccine development. In this survey, 127 serum samples of suspected human were collected from different parts of Mazandaran during eight months (during november 2006 to july 2007) and were tested by indirect immunoflurescence assay (IFA) in Amol Branch, Institute Pasteur of Iran. To recognize common pathogenic serotypes, collected samples were tested using Microscopic agglutination test (MAT) in Leptospira Research Laboratory, Faculty of Veterinary Medicine, University of Tehran. Prevalence rate of Leptospirosis in Mazandaran province was 58.26% using IFA and MAT. In this survey, 74 samples were positive which 82.43% of them were belonged to male and 17.52% to female. Rice field workers showed the most frequent occurrence of infection, so among positive cases 66.22% were to the rice field workers and showed significant difference with other occupations (P=0.007). Among 107 samples that were collected from males and 20 from females, 57% and 65% samples were positive, respectively. There was no significant difference between gender and Leptospirosis (P>0.05). Living place (urban or rural) and contact with animals did show no significant difference with Leptospirosis. The most positive cases were found in age range of 40-50 years (25.67%). The most prevalent serotypes which were recognized in Mazandaran province using MAT, included, Ballum (16.77%), Sejroe (14.29%), Tarassovi (13.64%), Australis (11.69%), Pyrogenes (7.79%), Javanica (6.5%), Icterohaemorrhagiae (6.5%). Using a MAT titer of ³ 1:100 as the gold standard, The sensitivity of IFA for the detection of Leptospirosis was 38.8%, the specificity was 88.33%, the positive predictive value was 78.78%, and the negative predictive value was 56.38%. It seems that Leptospifrosis is widespread in Mazandaran province and the authorities should pursue prevention and control measures of this multifaceted disease with more enthusiasm to prevent spread of the disease. Demographic analysis of the results indicates that leptospirosis is typically an occupational disease in the region.

This study carried out in the Shahid Marjani sturgeon reproduction center from July to October 2006. MeHg bioaccumulation trends were measured in gill, liver, intestine, kidney and muscle tissues of the Beluga. The groups of Beluga juveniles were exposed to four dietary containing different concentration of MeHg during 70 days. The treatments were: 1- Control group (0.04 mg/kg) 2- Low dose group (0.76 mg/kg) 3- Medium dose group (7.8 mg/kg) 4- High dose group (16.22 mg/kg). The results indicated that bioaccumulation levels in all tissues were correlated positively with MeHg concentration in food and exposure duration. MeHg concentration in liver with 98% correlation was the highest and with 72% correlation in intestine had the least relationship with treatment duration. Final analysis showed that liver, muscle and kidney of Beluga can be considered as the index tissues for investigation of Hg bioaccumulation.

Cadmium is a heavy metal with high biological toxicity which accumulates in soil usually by using chemical fertilizers or industrial pollutants. In order to study the effects of cadmium on biological nitrogen fixation and finding more resistant strains, the effects of cadmium on microbial growth, nodulation and symbiotic function of four different strains of Sinorhizobium meliloti were considered. They were cultured in TY liquid medium with different concentrations of CdCl2 and their growth was measured by OD (Optical Density) test. More over the effect of cadmium on legume-rhizobium symbiosis was studied by culturing the germinated alfalfa seeds in perlit medium. Plants at three leaves stage were infected by Sm strains mentioned above and the pots were placed in a growth chamber with 16 h light, 18-22ºC temperature and 50% humidity for eight weeks. After this time the number and weight of nodules, root length, root and whole plants dry weight; root and shoot total proteins, photosynthetic pigments content, and nitrogenase activity were measured. The results showed decrease of growth, nodulation and N2 fixation ability of all Sm strains, by increasing Cd concentration. But there were significant differences between strains; so that Sm nifK- (pSRK9) has the most sensitivity to Cd. Sm WT, Sm WT (pSRK9) and Sm nifH- (pSRK9) growth egregiously in presence of cadmium compare to Sm nifK- (pSRK9). Sm WT (pSRK9) has more nodulation and N2 fixation ability in presence of cadmium. Plants with the more nitrogen fixation ability have the more ability for protective component biosynthesis. Protection of the photosynthetic system against oxidative stress may be one of the reasons that cause better growth of the plants with active nitrogen fixing system, compare to others.

Temperature is one of the main factors which affect fruit and seed formation. In this study the effect of heat stress on in-vitro pollen germination and pollen tube growth in capsicum annuum L.var. Malali were investigated. After onset of reproductive phase the plants were divided into two groups; control group were held into temperature regime treatment (25±3ºC day/ 18±3ºC night) and treatment group were held into temperature regime treatment (38±3ºC day/ 28±3ºC night) Pollen grains were collected from both control and those which were under heat stress were cultured on culture medium containing 10% sucrose , 0.1 mM boric acid, 1mM calcium chloride and 1% agar. The plates contained pollen grains were then transferred to growth chamber with different temperature from o to 40°C with 5°C interval. Pollen germination percentage and the rate of pollen tube growth during 1, 2 and 3 hours after treatment were calculated. Pollen germination in control flowers was 80% in 20-25°C and reached to lower than 5% in temperature treatments of >35°C and <5°C. Pollen germination in flowers from treatment group was about 15% in 20-25°C and reached to lower than 5% in temperature treatments of >30°C and <10°C. Pollen tube growth in control plants decreased from 0.5 mm in 20-25°C to lower than 0.005 mm in temperature treatments of >35°C and <10°C. Pollen tube growth in treatment group decreased from 0.07 mm in 20-25°C 0 mm in temperature treatments of >35°C and <10°C. Cross sections of anther for both control and heat stressed samples showed a significant increase in grains which were irregular, infertile and hollow in heat treated plants. The results from this research indicated that male reproduction organs in pepper plants are highly sensitive to heat stress.

In this research, plant diversity of Artemisia sieberi habitats has been studied in Iran. The habitats situated in hammadas and alluvial plains of central plateau of Iran, with semi-arid, arid and hyper-arid climates. Altitude range of the habitats is 830–2350 m, annual precipitation range 59.5–350.1 mm and average of annual temperature 12.5–20.8°C. Plant specimens were collected from 34 A. sieberi habitats in 10 provinces within three vegetative seasons, 2005-2006. The specimens were determined in Central herbarium of Iran by using several floras. Their life forms were recognized according to Raunkiaer method. A total of 372 plant species were identified in A. sieberi habitats. They are including two gymnosperms, 318 dicotyledones and 52 monocotyledones, which belong to 42 families and 195 genera. Gymnosperms have one family and one genus, dicotyledones 34 families and 166 genera and monocotyledones seven families and 28 genera. Asteraceae (18%), Chenopodiaceae (10.2%), Fabaceae (8.9%) and Poaceae (7.8%) have the higher numbers of species, respectively. Therophytes with 40 % are the most frequent life form in A. sieberi habitats. Hemicryptophytes with 28.8% are situated after them.

The amount of ethylene increases in stress conditions in plants. Some of plant growth rhizobacteria contain ACC deaminase enzyme that is capable to convert 1-aminocyclopropane-1-carboxylate, the immediate precursor of ethylene in higher plants to ammonia and a-ketobutyrate that causes decrease in stress ethylene level. In this study 330 strains of indigenous rhizobia including Sinorhizobium meliloti (168 strains), Rhizobium leguminosarum bv. viciae (44 strains), R. leguminosarum bv. phaseoli (58 strains) and Mesorhizobium ciceri (60 strains) native to different soils of Iran were evaluated for ACC deaminase production. The results showed that 28.2% of strains synthesized ACC deaminase enzyme. The most number was belonged to the Sinorhizobium meliloti (46.5%) and the least number to the Mesorhizobium ciceri (6.7%). The strains with ACC deaminase enzyme were categorized in five groups of 0, 2-4, 4-6, 6-8 and 8-10 mm based on the colony diameter as compared to control. Four isolates of each group were selected for future investigation. The selected isolates did not show phosphate solubilizing properties and HCN production as well. The selected strains synthesize auxine (IAA) between 0-21 μgr.ml-1.24h-1. In these strains, the ability to produce siderophores based on the ratio of corona to colony diameter on CAS agar medium was zero up to 2.7. The future work on these strains would be the development of biofertilizers with ACC deaminase properties.

In other to study the effects of different root zone temperature (RZT) and two strains (Tehran and Zanjan strains) on some grass-pea (Lathyrus sativus) varieties, an experiment was conducted in a controlled-environment chamber in air constant temperature 25°C. In this experiment, 3 varieties of grass-pea namely ardabil, shahrekord and zanjan and four root-zone temperatures included 5, 10, 15 and 25°C was evaluated as factorial with treatments organized following a randomized complete block design, with 3 replications. Result showed that there were differences among the grass-pea varieties for nodulation and nitrogen fixation, growth and development and dry weight. RZT enhancement increased nodulation and nitrogen fixation in varieties. Strains had different effect on measured traits of varieties, as that Inoculated plants with tehran strain increased plant height, leaf number and area, nitrogen concentration in comparison with inoculated plants with strain zanjan. Inoculated plants of zanjan and tehran strains produced the most nodule number and nodule colonization number, plant nitrogen concentration and nitrogen fixation at 15 and 25°C RZT respectively.

Endoglucanase is a subgroup of cellulases that are able to cut cellulose at accessible points along its length and produces oligosaccharide fragments. In this research β-1, 4 endoglucanase activity of isolate R4 of Aspergillus niger was assayed under various environmental conditions, including carbone source, pH, inducer and culture period. The results showed that isolate R4 showed the highest enzyme specific activity in optimum conditions as follow: CMC as carbone source, pH=8, lactose as inducer and culture period of 2 days. For amplification and study of β-1, 4 endoglucanase gene, CTAB method used for DNA extraction. The expected PCR product with 1297 bp was amplified using pfu DNA polymerase and two specific primers (EGAF/EGAB). The amplified fragment was confirmed by restriction pattern using PstI and HindII. The amplified DNA fragment was cloned into pUC19 and sequenced. Homology between this sequence and other reported related genes in GenBank are discussed.

Effects of two elicitors methyl jasmonate (MJA) and salicylic acid (SA) on the activity of antioxidant enzymes catalase (CAT) and ascorbate peroxidase (APX), and activity of phenyl alanin ammonialyase (PAL), and contents of phenolics and flavonoids in 65-days old roots of in vitro cultured plants were studied. Activities of CAT and APX enzymes in aerial parts were increased after 24 h post treatment with 2mM MJ, while similar increment was observed in roots after 48 h. Activities of these enzymes increased in roots of treated plants with 1 and 2 mM SA after 24h. Activity of CAT decreased in roots of all treated plants; while activity of APX was decreased in roots of treated plants with 1 and 2 mM SA after 48h. Moreover, significant increase in contents of phenolics and flavonoids was observed after 24 h elicitation with MJ and SA. The activity of PAL increased after 24h elicitation and for both elicitors. This observation was in accordance with increment of phenolics and flavonoids contents at similar times of elicitation.

Crimean–Congo hemorrhagic fever (CCHF) is a potentially fatal disease caused by a tick–borne virus in the family Bunyavirdae. The disease occurs in parts of Africa, Asia, Middle East, and Eastern Europe. During recent years, an increasing number of human CCHF cases have been diagnosed in Iran, but very little in formation is available on the prevalence and genetic diversity of CCHF in Iran. In the present study, CCHF virus (CCHFv) isolate from five Iranian patients infected during 2002 were examined genetically. Nucleotede sequencing of the S-segment encoding the nucleocapsid protein (NP), respectively, revealed that the different isolates were related closely to one another. Phylogenetic analysis of partial S-segment nucleotide sequences showed that the viruses clustered along with strain from Pakistan in one distinct lineage. (99.4%) and this viruses probably is transmitted from Pakistan to Iran. However due to the spread of the disease in a broad territory around Iran and nieghbouring countries like, Turkey, Iraq, Pakistan, Afghanistan, Russia the possibility of transmission of the disease from these countries cannot be excluded.

In this study, samples were taken from different sites of Parishan lake in 12 months at regular intervals.The amounts of fecal bacteria Escherichia coli and Enterococcus faecalis were determined by Most Probable Number method. The results indicate there are a direct relationship between precipitation rate and the microbial pollution of the lake. The calculated fecal coliform ranges in April, November, February and March were more than 100CFU/100ml which were beyond the WHO normal ranges. To determine the human or animal fecal pollution origins, Fecal coliform/Fecal streptococci ratio was calculated in different months of the year, 50% of which were above 4 and in the rest of the cases it was above 0.7, Consequently it can be concluded that the entry of human wastes from villages around the lake is the main source of the Parishan lake pollution while domestic and wild animal wastes probably have played lesser role in the pollution of the lake.

Sugar beet is a recalcitrant plant for genetic manipulation. An efficient and simple method for shoot regeneration can facilitate sugar beet gene transformation. In this research, shoot tips were cultured in different pretreatments including 0.1, 0.5 and 1mgl-1 BAP and 1mgl-1 BAP with 1 mgl-1 NAA. The leaf explants were cultured in different hormonal treatments and percentage of responsive leaves to shoot regeneration were determined. Data were analyzed in factorial experiment with randomized complete block design. Leaf explants derived from pretreatment containing 1 mgl-1 BAP produced the highest (65.4%). Effect of hormonal treatment on shoot regeneration from leaf explants was not significant. Pretreatment containing 1 mgl-1 BAP was an important factor in shoot induction. Individual plants of 9597-P26 sugar beet half-sib family as different genotypes were screened for their ability to form adventitious shoots on leaf explants. Effect of genotype on adventitious shoot regeneration was significant. Though, shoot regeneration of leaf explants derived from 1 mgl-1 BAP pretreatment was less dependent genotype.

Campylobacter is the most common cause of acute bacterial gastroenteritis in humans worldwide. The common source of infection is contaminated food, particularly poultry. To investigate the occurrence of Campylobacter jejuni in kerman poultry farms, 90 cecal samples from 9 poultry farms (10 samples each farm) were taken. Samples enriched in Preston Enrichment broth, then were plated on campylobacter selective agar supplemented with defibrinated sheep blood and incubated for 48 hour at 42ºC under micoaerophilic condition. Presumptive campylobacter colony from each plate was cultured and tested for Gram staining, production of catalase and oxidase. Campylobacter positive colonies were confirmed with polymerase chain reaction (PCR). Campylobacter jejuni was isolated and confirmed from 3.3% samples.