مجله دانشکده پزشکی اصفهان
پیاپی 349 (هفته اول آبان 1394)

Achieving to a scaffold with suitable properties is a current challenge in tissue engineering. Polyhydroxybutyrate (PHB) is a polymer which has attracted attentions due to have favorable properties such as good biocompatibility and relative high mechanical properties; but, its hydrophobicity and brittleness are not suitable for cartilage tissue engineering scaffold fabrication. Blending with other polymers is a strategy to solve this problem. This study aimed to prepare electrospun PHB/chitosan (CTS) blend scaffold and to investigate its structural properties and cellular behavior. First, polymeric solutions of PHB in trifluroacetic acid (TFA) were electrospun and after optimization of parameters, various percentages of chitosan with aim to improve its hydrophilicity and mechanical properties were added to polymeric solution and electrospun. To characterize prepared scaffolds, scanning electron microscopy (SEM), tensile strength test, Fourier transform infrared spectroscopy (FT-IR), contact angle measurement, and porosimetry were performed. According to the obtained results, the scaffold containing 15 and 20 percent of chitosan were selected as the optimized scaffolds and were examined for rabbit chondrocyte cell adhesion test. Scanning electron microscopy images showed that electrospinning of the solution with PHB of 9% weight in 21 kilovolt at 15 cm produced the most uniform fibers; the scaffolds containing 10, 15 and 20 percent of CTS have more uniform fibers than the scaffold containing 5 percent. Finally, based on the results of other experiments, the scaffolds containing 15 and 20 percent of chitosan were identified as optimized scaffolds. SEM images showed good chondrocyte cell adhesion on these scaffolds. Addition of chitosan to PHB, can improve its mechanical and biological properties and hydrophilicity.

Some of the studies showed that abnormal high level of iron and cholesterol in the brain had neurodegenerative effects such as in Alzheimer's disease. But, the previous studies in this field were not enough and had controversy in results. As the prevalence of Alzheimer's disease is increasing, this study aimed to evaluate the effect of iron and cholesterol on the level of neuronal apoptosis in dentate gyrus of hippocampal formation. Male New Zealand white rabbits were divided into the control, the iron (50 mg/kg; gavage), the high-cholesterol diet (containing 2% cholesterol), and the high-cholesterol diet plus iron groups. Serum levels of total cholesterol, high-density lipoprotein (LDL), and low-density lipoprotein (HDL), before and after the regimen for 6 weeks, were measured. Then, the rabbits for immunohistochemical staining via TUNEL test (Terminal deoxynucleotidyl transferase biotin–dUTP nick end labeling) and evaluation of neuronal apoptosis in dentate gyrus of hippocampal formation were anesthetized and brains were dissected. After the regimens, serum levels of total cholesterol, LDL, and HDL in the cholesterol-receiving groups increased significantly compared to the control group (P < 0.05 for all). Histological results demonstrated that neuronal apoptosis in the dentate gyrus of the high-cholesterol diet group increased significantly (P < 0.05) comparing to the control group. Iron had not significant effect when used alone or with cholesterol on neuronal apoptosis in the dentate gyrus in rabbits. Our recent results showed that high-level cholesterol diet had significant effect on the neuronal apoptosis in the dentate gyrus in rabbits; but use of iron alone or with high-level cholesterol diet had not significant effect on it.

One of the major challenges in adult surgery is hypertension. Hypertensive patient are in danger of myocardial ischemia, increasing blood pressure in recovery room, kidney injury and cerebral artery damage. Regarding the previously reported positive effect of alprazolam in decreasing this complication, we decided to evaluate its efficacy in hypertensive patients undergoing surgery under general anesthesia. The present randomized controlled trial was conducted in 2014 in Alzahra Hospital, Isfahan, Iran. Study subjects (age range between 54 and 76 years) were candidates for elective surgery under general anesthesia. Patients were randomly divided into 2 groups, intervention and control. Control group received no drug and intervention group received alprazolam tablet (0.5 mg) before the surgery. Systolic and diastolic blood pressure, heart rate, respiratory rate, pulse oximetere, and O2 saturation during the surgery and pain severity, extubation time, recovery time and the dose of analgesic drugs after the surgery were evaluated and compared between the groups. Increasing blood pressure in the first 40 minutes of surgery (P = 0.001), pain severity (P = 0.012) and the dose of analgesic drugs (P = 0.001) were significantly less in intervention group compared to the control group. According to our results, alprazolam has an optimal efficacy in controlling blood pressure in hypertensive patients undergoing surgery and reducing pain severity in recovery room. In the absence of contraindications, it could be used as a prophylactic treatment in this group of patients.

Influenza viruses cause acute respiratory infections in humans, which can often be accompanied by pandemics with varying rates of illness and even a fetal end. Current vaccines target the variable globular part of hemagglutinin (HA); so, their effectiveness is limited and they need perpetual updating. To prepare universal vaccine, scientist's effort is focused on conserved antigenic parts of influenza virus such as hemagglutinin stalk domain which is more conserved compare to its globular head. The aim of this study was evaluating the immunogenicity of influenza A (H1N1) HA2 peptide in mouse model. To prepare HA2 protein, the expression vector encoding the gene of interest (PET-28a/HA2), was transformed into Escherichia coli BL21-DE3 competent cells. Recombinant HA2 protein was extracted and purified using Ni-TED columns under denaturing conditions, refolded and desalted via step-wise dialysis. The HA2 concentration was determined via using Bradford protein assay. Six-week-old BALB/c mice in different groups were immunized intradermally with HA2 alone or supplemented with Freund or Lm.HSP70221-604 as adjuvants. Two groups were injected with HSP70 and phosphate buffered saline (PBS) as negative controls. Humeral immunity in vaccinated mice was measured using the enzyme-linked immunosorbent assay (ELISA); and finally, mice were challenged with one lethal dose (LD90) of PR8 virus. The protein expression, extraction and purification stages were confirmed using sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) electrophoresis. The highest antibody response was measured in mice vaccinated with HA2-Freund, as expected. Specific antibody response in group received HA2-HSP70 was of higher titer than HA2 alone. More over HA2-HSP70 group surprisingly showed higher level of protection against lethal H1N1 (PR8) challenge compared to other groups. It has been proved that HSP70 can induce specific response and innate immunity via stimulating CD8+ T-Cells, CD40, TLR2, TLR4 and cytokine secretion. Our results showed that HA2 alone or supplemented with HSP70 protected mice against lethal influenza challenge and could be considered as a universal vaccine.

The results showed success of the health system to detect suspected cases of the measles and appropriate sampling from suspected cases that were more than expected. In addition, per every one million population of Iran in 2014, 1.27 of cases of measles were reported; that a numbers of confirmed cases observed in Afghan refugees. Low levels of immunization coverage in eastern neighboring countries and high immigration to Iran, are the main challenge of measles elimination in Iran. The gradual accumulation of susceptible individuals, due to lack of proper vaccination or failure to respond to immunization, may underlie the development of outbreaks of measles in Iran.