SM Journal of Biology

Archive Articles

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Graph Theory: A Powerful Research Tool for Biological Network Analysis

In the pre-genome era, traditional molecular biology provides very informative knowledge on how individual bio-molecule, i.e. DNA, RNA and protein, perform biological functions. Networks of interactions among bio-molecules are fundamental to all biological processes; for example, the Gene Regulatory Network (GRN) can be described as a complex network of genes regulated by protein binding. Cellular processes are controlled by various types of biochemical networks; such as (i) metabolic networks, (ii) Protein-Protein Interaction (PPI) networks, (iii) GRN, and (iv) signal transduction networks. Biochemical networks are complex in nature; they consist of a large number of bio-molecules, interacting with each other give rise to biological responses and stabilities. In the post-genome era, it is more productive to investigate how bio-molecules regulate or cooperate on a system level. The graph theory approach is a powerful tool for investigating the underlying topological structures of different molecular networks. A great diversity of graph theoretical notions is discussed to characterize biological networks. T he theory of complex networks plays an important role, ranging from computer science, sociology, engineering and physics, to bioinformatics etc. Within the fields of bioinformatics, potential applications of network analysis include drug target identification, determining bio molecules’ pathways and function, and designing effective strategies for treating various diseases. Molecular networks are the basis of biological processes. Such networks can be decomposed into smaller modules, also known as network motifs. These motifs show interesting dynamical behaviors, in which co-operatively effects between the motif components play a critical role in human diseases. Some of the network motifs are interconnected which can be merged together and form more complex structures, the so-called Coupled Motif Structures (CMS). These structures exhibit mixed dynamical behavior, which may lead biological organisms to perform specific functions.

Chien-Hung Huang*


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Carbapenem-Resistant Acinetobacter baumannii: Epidemiology and Prevention in Iran

Over the past 10 years, dissemination of Carbapenem-Resistant Acinetobacter baumannii (CRAB) has led to an increase in the prevalence of Carbapenem-resistant Gram negative bacteria in the Iran. Carbapenems are used as a first choice drug for treatment of Acinetobacter baumannii infections. Extensive resistance to Carbapenemes, has become a major challenge for treatment of Acinetobacter baumannii infections. Infections caused by CRAB have limited treatment options and have been associated with high mortality rates in worldwide. Resistance to Carbapenemes first was reported in 1991 than its distribution was observed worldwide. Recent studies have revealed that 98% of Acinetobacter baumannii isolates in different Tehran hospitals are resistant to Carbapenemes (Imipenem and Meropenem). While the rate of resistance to Carbapenemes was reported to be 52/5% in 2009. Several mechanisms are involved in developing of CRAB. These mechanisms include the enzymatic hydrolysis mediated by the oxacillinases of Ambler class D OXA-type, Carbapenem hydrolyzing-β-lactamases of molecular class B and sometimes alteration of Penicillin-Binding Proteins (PBP) or increased activity efflux pumps [1]. Metallo-β-Lactamases (MBL) and oxacillinases are found to be more frequent. So far the oxacillinase genes such as blaOXA-23-like, blaOXA-24-like, blaOXA-51-like and blaOXA-58 like also MBLs such as Seoul metallo-β-lactamase Imipenemase (SIM), Sno Paolo metallo (SPM), New Delhi Metallo-β-lactamase (NDM), Verona Integron-encoded Metallo-β-lactamases (VIM) and Imipenemase (IMP) have been reported in Acinetobacter baumannii isolates. There have been numerous studies performed aiming to identify these mechanisms in Iran [2].

Habibeh Adibhesami1, Abbas Farahani2, Arezoo Asadi3 and Davoud Afshar1*


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An Epidemiologic Survey on Trichomonas Vaginalis Infection in Pregnant Women of Urmia City, North West of Iran, 2015

Background: Trichomoniasis is an extremely common infection worldwide and is associated with important public healthproblems, including amplification of HIV transmission. This symptomatic and asymptomatic disease is more frequently in pregnant women due to hormonal changes and reducing the vaginal acidity during pregnancy. Thus the aim of this study was to evaluate Trichomonas vaginalis infection in pregnant women of Urmia city, North West of Iranfor the first time in 2015.

Methods: This descriptive cross-sectional study was conducted on 800 pregnant women who referred to main medical laboratories in Urmia. Vaginal samples were obtainedfrom them and examined by wet mount and culture methods for the detection of T. vaginalis.

Results: According to the results, T. vaginalis was detected in 29 out of 800 participants (3.63%) by using culture methods whereas only 22 of 29 infected people were positive with the wet mount technique. Gestational age had a significant relation with Trichomoniasis (P<0.05) while age and symptoms showed no significant relation with Trichomoniasis (P>0.05).

Conclusion: This study showed low prevalence of T. vaginalis infection in the study population.Since clinical signs of trichomonal vaginitis are the same of other Sexually Transmitted Diseases (STD), a confirmatory laboratory diagnosis is necessary. Wet mount technique is not as well as culture method sensitive and accurate for detection of T. vaginalis.

Reza Abdolah Nezhad1* and Farzaneh Kaffashi Boukani2


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The Impact of Seed-Borne Fungi Associated with Roasted Cashew (Anacardium Occidentale L) Nuts on Its Food Value, Mineral and Anti-Nutrient Contents and Human Health

Isolation and identification of seed-borne fungi associated with cashew nuts from source of production and market was carried out. The proximate, mineral and anti-nutrient composition of the source of production and the market samples of roasted cashew nuts were also investigated. The result of isolation of fungi associated with the nuts from source of production and the market showed that Claviceps purpurea, Aspergillus fischeri, Aspergillus carbonarius, Aspergillus flavus, Aspergillus tamrii and Aspergillus fumigatus were associated with seeds from samples from the two sources. The ash, lipid, carbohydrate and protein contents of the source sample were relatively higher, while the moisture, fibre and vitamin C content of the markets samples were relatively lower. The Sodium, Zinc, Nitrate, Nitrogen and phosphorus contents of the market samples were observed to be higher when compared with the source sample, while the phosphate, Magnesium, Calcium, Manganese and Copper contents of the source samples were higher than the market sample. The saponin and the cyanogenic glycoside content of both market and source samples was the same, while the alkaloid content of the source samples were relatively higher. The flavonoid content of the market sample was observed to be higher when compared with the source samples.

Ibiam, O. F. A1*, Nweke, A1 and Kanayochukwu, U. L2


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Stroma Features in Prostate Cancer Diagnosis and Prognosis

The oncogenesis of Prostate Cancer (PCa) is a process involving epithelial cells of the gland and their interaction with the stroma. Reactive stroma formation has been shown to be critical in the progression of many cancers. In PCa, the reactive stroma is unique when compared with other cancer types and characterized by replacing the normal well differentiated smooth muscle cells with fibroblasts and myofibroblasts. The Masson’s trichrome stain and immunohistochemistry (IHC) / immunofluorescence studies characterized these changes and a grading system of reactive stroma has been developed. In this review, the changes of the molecular and morphometric features of the reactive stroma during the progress of PCa, and their use in clinical implications in the diagnosis, prognosis prediction and potential treatment of PCa are discussed.

Guangjing Zhu1* and Robert W Veltri1