RESEARCH JOURNAL OF UNIVERSITY OF ISFAHAN "SCIENCE"
Year:2008 | Volume:31 | Issue:2 (BIOLOGY)|Papers Count:13

The phosphatidylinositol 3-kinases (PI3Ks) are a family of serin/thereonin kinase enzymes which are activated in response to external stimuli by tyrosine kinase receptors. Active PI3K participate in various signaling pathway including proliferation, differentiation, cell cycle control and apoptosis through producing PIP3 as second messenger and activating AKT. Class I of this family enzyme is heterodimer comprised of a catalytic and a regulatory subunit. Mutations of catalytic subunit can increase the enzyme activity and cause uncontrolled growth of the cells. This finally results in the cells, becoming cancerous. Previous studies indicate high percentage of mutation in this gene.Considering the high incidence of breast cancer in Isfahan, in this study mutations of this gene in breast cancer patients are investigated. DNA from 60 patient samples and 35 controls were extracted and the exons were amplified by PCR. Then mutations of this gene were analyzed by SSCP technique. Based on the results of this study, 28% mutations in this gene were reported, which approves the oncogenic feature of the PI3K. Positive association between mutations of the gene and lymph node involvement with P=0.0 and odd ratio=7 indicates the role of this pathway in" metastasis. The high percentage of mutation in this gene and its role in metastasis show the importance of this pathway for therapeutic purposes in order to prevent and stop the growth of breast cancer.

Teucrium polium belongs to Labiatae family that grown wild in most of regions of Iran. Germander (Teucrium polium) is an edible plant which is also widely used in folk medicine. This plant was collected from Broujerd Mountains of Lorestan province in Iran. The air-dried epigeous parts were subjected to hydrodistillation method (in a yield 0.1% w/w). Identification of essential oil costitiuents was made by GC and GC/MS. The antibacterial tests were carried out by drilling well and measuring diameter of inhibition zone. The major component is a-pinene (13.95%), b- caryophyllene (12.35%), germacrene- B (11.74%), b- pinene (8.75%) and limonene (7.60%). The results of the antibacterial activity showed that the oil has notable antibacterial activities aginest of most the Gram- positive and Gram-negative bacteria which these antibacterial activities were more than gentamicine.

Colorectal cancer is the most prevalence malignancy that affect on stomachic system. After lung and breast cancer, colorectal cancer is the most common of death in the western world. Colorectal adenocarcinoma accounts for over 90% of the malignant tumors of the large bowel. Modification in cell adherent molecules and enzymes that degrade intra cellular membrane have important role for colorectal tumor creation. Matrix metalloproteinase enzymes degrade different component of extra cellular matrix and cause tumor creation, cancer development and metastasis. MMP3 overexpression due to single nucleotide polymorphism (SNP) 5A/6A at the -1171 position of the MMP3 gene promoter effects on tumor malignancy and cancer development. A case- control study was performed including 120 cancer patients from Emam Khomeini hospital in Tehran and Seid Alshohada hospital in Isfahan. After MMP3 promoter genotyping, the results were analyzed by SPSS 12.0 software. The colorectal cancer patients were divided in to two groups: M+non- metastasis patients and M-, the metastasis-free patients. The MMP3 genotypes were similar between controls and patients (P=0.43, OR=0.78, 95%CI, 0.37-1.64), but the 5A/5A genotype was more prevalent in the M+groups than controls (P=0.74, OR=2.91, 95%CI, 0.94-8.98). This frequency was more prevalent than M- (P=0.65, OR=1.90, 95%CI, 0.69-5.2). So we supposed the MMP3 5A/6A promoter polymorphism doesn' t appear to influence colorectal among colorectal cancer patients but 5A/5A genotype with MMP3 over-expression cause colorectal cancer development and metastasis.

Biofilm is a functional consortium of microorganisms attached to the surface and is embedded in the extracellular polymeric substances (EPS) produced by the microorganisms. The biofilm consists of microbial cell clusters with a network of internal channels or voids in the extracellular polysaccharide and glycoprotein matrix (EPS). Biofilms, due to special structure and EPS, are more resistant to antimicrobial agents. Thus control measurement such as heating, drying and detergents cannot eliminate them. Biofilms even with cleaning and disinfecting methods can remain on various surfaces which may assist the survival of pathogenic and spoilage bacteria in the food processing environment, a contributing factor in foodborne disease outbreaks.In this study biofilm elimination potentional and bactericidal effect of current food industry and clinical disinfectants on biofilm of pathogenic bacteria such as Salmonella enteritidis, Listeria monocytogenes and Staphylococcus aureus and environmental bacteria from meat processing factory were assessed by microtiter plate method. Biofilm elimination potentional and bactericidal effect were assessed by crystal violet and TTC stain, respectively. Results indicated that bacterial biofilms are resistant to disinfectants. However, Hypochlorite Sodium, Propanol and Peroxide Hydrogen had the most Biofilm elimination and Glutaraldehyde had the most bactericidal effect on biofilms. Thus, efficiency of disinfectants based on strain, structure and environmental condition is different. This indicates the importance of appropriate choice of disinfectants in industries and hygiene centers for prevention and control of biofilm formation.

Chlorophyta are an important group of phytoplankton which are widespread in freshwater. Samples of Chlorophyta were taken at four stations by Nansen sampler from August 2005 to June 2006. Samples were fixed with 4% formaldehyde and were concentrated and studied with known key. A total of 17 genus and 26 species were identified in Zayandeh Rood Dam Lake. Chlorella Bey, Nephrocytium Naeg, Oocystis Snow and Elakatothrix Wille were the most important genera. Pedi strum integrum var priva printz was found for the first time in Iran for this lake. Density of Chlorophyta was increased in warm seasons because of high temperature.According to algal flora, it could be concluded that, Zayandeh Rood Dam Lake is oligomesothroph.

The life cycle of flowering plants is divided into two phases, a dominant diploid sporophyte phase and a transient haploid gametophyte phase. During the complex process of plant sexual reproduction, the male gametophyte or pollen grain and female gametophyte are formed. Female gametophyte or embryo sac is formed in the ovule and consists of seven cells. Double fertilization of egg cell and central cell initiates development of the diploid embryo and of the triploid endosperm, respectively. Flower bud and fruits of Petunia x hybrid were collectd, fixed and studied. Gynocium is sessile and contains two syncarpous carpels.Ovary has two locules and several anatropous ovules. The female gametophyte, also referred to as the embryo sac or megagametophyte, develops within the ovule. It is the polygonum type female gametophyte.After fertilization, the stages of development of embryo are as stages of globular, cell differentiation, heartshaped and cotyledonary (mature). The endosperm persists in the mature emabryo and functions as storage tissue for germinating seedlings. So these seeds are termed albuminous.

Monascus is a microscopic fungus with extensive industrial applications such as production of food grade pigments and cholesterol-lowering drugs. The isolation and identification of M. purpureus and M.fumeus have been carried out for the first time in Iran by authors. In order to determine the optimal temprature and pH for the growth of the fungi they were cultured on MEPAG culture medium with 4 different tempratures (25, 30, 35 and 40oC) and 5 different pH (4, 4.5, 5, 5.5 and 6) thereafter colonies diameter was measured. The data were analysed by SPSS statistical software and the optimum temperature and pH for colonies growth were determined. The data analyses showed that the optimal temperature range for the species M. purpureus is 30 to 35oC and optimum pH is 4 to 5. For the species M. fumeus the optimum temperature is 30 to 350C and optimum pH is 4 to 5.5.

For investigation on study and compare nutritional efficiency in six hybrids including 103x104, 31x32, 107x110, 104x103, 32x31 and 110x107 in several nutrition management conditions, these hybrids were reared at three rearing duration and 4 and 5 instar. Hybrids were reared under four feeding levels in duding 5% higher than standard feeding table for silkworm htbrids, equal to standard table, 5% lower than standard table and 10%lowerthan standard table. Rearing duration included spring 2003, spring2004 and autumn 2004. The parameters studied were included amount of ingestion and digestion, percentage of ingestibility and digestibility, reference ratio, cocoon weight, cocoon shell weight, cocoon shell percentage, efficiency of conversion of ingested (ECI) and digested (ECD) food into cocoon weight and cocoon shell weight. From obtained results, it was showed at all rearing periods, four nutritional indices including amount of ingestion and digestion, ingestibility percentage and digestibility percentage in reverse hybrids (B, D and F) were higher than un-reverse hybrids (A, C and E). Furthermore at each three rearing periods, ECI and ECD into cocoon shell weight and ECI and ECD into cocoon weight in reverse hybrids (B, D and F) were less than un reverse hybrids (A, C and E). Investigation on ECI and ECD into cocoon weight and cocoon shell weight at second period showed these parameters were littile in hybrids E and F. Meanwhile these parameters decreased at autumn season. ECI and ECD into cocoon weight and cocoon shell weight in all hybrids at autumn season were less than spring season.

Antibiotics are extensively used as selective agents in genetic exchange experiments. In the case of moderate halophiles, it has been reported that when they are grown at their optimal salt concentration, (usually about 10%) they tolerate very high concentrations of the majority of the antibiotics. The susceptibility of some of moderately halophilic collection strains belonging to different genera to some common antibiotics has been investigated and effect of NaCl salt different concentrations (0%, 5%, 10%, and 15%) on the operation of mentioned antibiotics has been studied. Antibiotic sensitivity was tested by Kirby-Bauer's disk diffusion method on Muller Hinton Agar medium (M.H.A). Zone of inhibition was measured and sensitivity was determined against standard inhibition zones. Three different patterns of tolerance to Antibiotics were found when salt concentration (NaCl) was varied in the testing media. The first one included the responses to erythromycin, vancomycin, where only minimal effects on the susceptibility were found or was not seen any effect. In the second group, including the responses to gentamycin, amikacin, a remarkable and gradual increase of toxicity was detected at lower salinities. Thirdly, the highest heterogeneity was found for the rest of antimicrobials assayed, where the effect of salinity was moderate dependent on both the individual strain and the antibiotic tested. The data presented here should facilitate genetic studies on moderate halophiles and design of selection media for genetic exchange experiments. Otherwise, identification of resisting halophilic bacteria that dispersein environment is very important because of genetic transformation of resistance gene to pathogen bacteria.