Pathobiology Research
Year:2020 | Volume:23 | Issue:3|Papers Count:7

The invention of microfluidic devices has led to a dramatic change in engineering, medicine, and biomedicine. Microfluidic devices provide the conditions for cell culture in real body dimensions. In the present study, a microfluidic chip was fabricated that is capable of keeping cells alive under dynamic flow conditions. This microchip consists of a microchannel in which cells are cultured. Different amounts of shear stress are exerted to the cells by passing culture media. The results of the flow field simulation show that in the flow rate of 1 to 100 microliters per minute, the shear stress distribution is uniform. In this range of flow rate, shear stress varies from 0. 005434 to 0. 5432dyn/cm2, which is within the allowable shear stress for cells. Large shear stresses, such as a flow rate of 1000 microliters per minute, cause the cell wall to rupture, and eventually disintegration. The experimental results confirm that the growth and proliferation of cells vary for different amounts of growth factor as a chemical factor. The cells filled the microchannel for a growth factor of 15% on the fifth day of culture, while without growth factor, the microchannel was filled on the seventh day. The results indicate that this microchip can maintain cells alive for more than a week. Also, by adjusting the flow, different amounts of shear stress can be applied to the cells. Therefore, this microchip can perform various cellular tests to investigate the effect of shear stress on the cells. . .

Aims: The common hepatitis B vaccination was designed based on alum adjuvant. This adjuvant is failed to stimulate cellular immunity so that, optimization is necessary for better stimulation of cellular immune responses. α--tocopherol is a key component of vitamin E that is considered as immunomodulatory agent to regulate immunity in order to decrease inflammation immune responses. Therefore, in the present study, the effect of α-tocopherol on the improvement of immune responses in hepatitis B vaccination was evaluated. Materials & Methods: commercial hepatitis B vaccine was formulated with α-tocopherol at the doses of 1, 5, and 10mg. The vaccine was injected into BALB/C mice three times two weeks apart. Ten days after the last injection, blooddrawing was performed from mice groups. The levels of IFN-γ , TNF-α , IL-4, and IL-2 cytokines and IgG total antibody, as well as IgG1 and IgG2a antibody isotypes, were measured by ELISA method. Findings: Formulated vaccine at the dose of 10mg of α-tocopherol is more potent in the significant increase of IFN-γ , TNF-α , and IL-2 cytokines and low dose result in improvement of humoral immune response. Conclusion: Immune response of vaccine formulated with α-tocopherol was dose-dependent and at the dose of 10mg demonstrated a significant increase of Th1 response and at the dose of 1mg result in increase of antibody responses.

Aims Salmonellosis is one of the common infectious diseases between humans and animals that is caused by the consumption of poultry meat and its products. The invA gene plays a critical role in the pathogenicity of Salmonella infantis. Marine organisms, including sea cucumbers due to their effective secondary metabolites, have been identified and studied with compounds with antioxidant, anti-cancer, antibacterial, and anti-inflammatory properties. The aim of the current study is to determine effect of sea cucumber extraction on S. infantis invA gene expression. Materials & Methods Poultry meat was sampled and S. infantis strains containing invA gene were isolated. The Hexane extract was extracted from sea cucumber colon tissue and its effects on S. infantis and its effect on gene expression were investigated by MIC and Real-time PCR, respectively. Findings From 450 samples, 12 S. infantis isolates were isolated. The PCR technique identified that all 12 isolates have invA virulence genes. MIC was determined 256μ g/ml. The rate of change for the invA gene was estimated-1. 21. Conclusion Hexane extract extracted from the sea cucumber caused reduction of invA gene expression in Salmonella infantis. So, it can be used as a therapeutic supplement against S. infantis.

Aims Flatfoot is one of the common complications in individuals. The study of ground reaction forces (GRF) in different activities has clinical importance. Therefore, the aim of the present study was to analyze the GRF during running in individuals with flatfoot compared with healthy subjects. Materials & Methods 12 healthy men and 12 male patients with flatfoot participated in this study. By two force plates (1000Hz), GFR components during the stance phase of running were measured. Independent t-test was used to investigate differences between groups. The significance level was p≤ 0. 05. Findings The results showed that there is a significant difference between the two groups in ground reaction force of Fx1 (p= 0. 001), Fx3 (p= 0. 03), Fy1 (p= 0. 001), Fz1 (p= 0. 03), Fz3 (p= 0. 01), and the mean difference between these components was lower in the group of flatfeet compared to the healthy group. Conclusion Reducing some of the surface reaction force components in flatfoot individuals may be affected by the range of motion and torque of different anti-gravity muscles or adopting a strategy of stiffening the knee in these individuals.

Aims Living cells have an electrical charge created by the presence of ions and free radicals. Magnetic fields interact with ions, especially ferromagnetic materials such as iron that affect living cells. A common feature of about 20 different diseases is the aggregation of proteins in the form amyloid structure. In the current study, the effect of static magnetic field (SMF) on the formation and the toxicity of amyloid structures was investigated. Materials & Methods CHO cells were exposed to 6mT SMF in three consecutive days, and the effect of SMF on the formation of amyloid structures in the intrinsic proteins of these cells related to the control was investigated using thioflavin T (ThT) binding assay. The formation of amyloid structures in CHO cells expressing human ProIAPP cells was analyzed by observation of proIAPP protein aggregates linked to GFP protein. The effect of SMF on the toxicity of lysozyme oligomers on CHO and Hela cells was also compared with the controls. Findings Exposure of CHO cells to magnetic fields does not have a significant effect on the formation of amyloid structures in the intrinsic proteins of CHO cells and the amount of these structures in CHO cells expressing proIAPP protein but can increase the toxicity of lysozyme oligomers on CHO and Hela cells. Conclusion The magnetic field does not have a significant effect on the formation of amyloid structures in the 6mT SMF strength, but it adds to the toxicity of these structures.

Viral fusion protein through protected areas called fusion peptide are essential for entry of the virus into the host cell by membrane integration. Fusion phenomenon occurs at the host cell surface or in the cytoplasmic compounds and in cytoplasmic components. The fusion proteins are divided into three categories according to variations that are likely during the fusion. In the first category, which includes viruses such as orthomixo, paramyxo, filo, corona, and retroviruses, definite domains of fusion proteins are cleaved and removed and they become mature and functional. The second group of fusion proteins is alpha and flaviviruses become their functional form without cleavage. The third category also includes viruses such as vesicular stomatitis, herpes simplex, and baculovirus, they have common features of the first and second categories. The changes in fusion protein in the levels before and after fusion, description of fusion proteins in viruses such as influenza, filo, and reoviruses as a prototype of fusion protein viruses and their therapeutic applications of fusion protein as potential drugs such as Lactoferrin and Enfuvertide in preventing the occurrence of fusion phenomenon is an important issue for consideration about multiplication and virus entry.

Osteoarthritis is the most common articular disease that has significantly affected the patients’ quality of life. As cartilage doesn’ t have any blood vessels and neurons, its treatment is a difficult task to do. Traditional therapeutic approaches, including the use of non-steroidal antiinflammatory drugs (NSAIDs) and surgical interventions, can only control the disease, and the joint will lose its functionality after a short period. Consequently, modern methods such as cell therapy and tissue engineering along with using various biomaterials are being attempted to repair degenerated cartilage tissue. Using interfering RNAs is another approach that targets specific destructive or malfunctioned RNA sequences and suppresses the responsible factors for cartilage tissue destruction. Hence, the degenerated tissue can gradually retain the balance between anabolic and catabolic activities. Identification of the affecting genes in degeneration or malfunctioning and their suppression has provided promising results for the treatment of diseases. In the current study, after introducing the tissue, the process of cartilage degeneration and osteoarthritis development, the researches that have investigated the effect of interfering RNAs on rehabilitating cartilage tissue via inhibition of cartilage matrix destruction are reviewed.