مجله دانشگاه علوم پزشکی شهید صدوقی یزد
سال بیست و هفتم شماره 12 (پیاپی 160، اسفند 1398)

One of the important findings in the pharmaceutical and medical industry is the use of the asparaginazase enzyme as an anticancer drug. The asparaginase enzyme, hydrolyzing the amino acid of asparagine, reduces this amino acid in the blood and causes the death of cancer cells. Today, the enzyme is used to treat various types of leukemia, particularly acute lymphoblastic leukemia, lymphosarcoma and non-Hodgkin's lymphoma. Despite the widespread use of asparaginase in the pharmaceutical and medical industries, there are major problems with the use of this enzyme, including immune system stimulation, response to the enzyme and the enzyme's glutaminase activity. It has been shown to be part of the side effects due to the glutaminase present in asparaginase. Extensive research is under way to find new sources of enzyme-producing with fewer immunological properties and side effects, and has brought hopes in this direction. In Iran, research has also been conducted over recent years to find new sources of enzyme production with new features and less side effects, and it is hoped that this research will reach the clinical and industrial stage. This paper is a review of the mechanism of enzyme activity, enzyme applications in various industries, sources of asparaginase production, and how it is produced and purified.

Future studies can introduce new asparaginase with potential benefits for patients. However, the search for new sources of enzyme-producing microorganisms with higher therapeutic potential is still ongoing around the world.

Sodium-dependent vitamin C transporter 2 (SVCT2) plays an important role in the transfer of ascorbic acid to slow-twitch fiber. The purpose of this study was investigating the effect of diabetes induction and exercise training on the level of ascorbic acid and muscle SVCT2 in rats.

In this experimental study, 20 male Wistar rats were randomly divided into four groups (n=5 per group): 1) healthy control 2) diabetic control, 3) diabetic exercise, 4) sham. Diabetic was induced by injection of Streptozotocin solution (55 mg / kg). The exercise program was performed 6 weeks of aerobic running on Treadmill, 5 sessions per week and each training session for 20-40 minutes at an intensity of 50-70% VO2max. Homogeneous tissue of soleus muscle and serum was analyzed to evaluate the effect of exercise training on ascorbic acid metabolism. Data were analyzed by SPSS version 18 software and one-wayANOVA test (P ≤ 0.05).

The results showed that there was significant differences (P < 0.05) between the level muscle and serum ascorbic acid in diabetic and diabetic + exercise groups compare to the healthy control and sham groups. But no significant differences was found in SVCT2 of Soleus muscle between groups (P> 0.05).

Induction of diabetes induces a decrease in muscle levels of ascorbic acid, which appears to be associated with a decrease in serum ascorbic acid levels, since no significant difference was found in SVCT2 levels. Also, exercise training had no significant effect on serum and muscle ascorbic acid levels of muscle SVCT2 levels.

Gastric cancer is the fourth most common cancer and the second leading cause of death in the world. Despite the recent advances in controlling and treating the disease, the survival rate of this cancer is relatively low. Various factors can affect the survival of the patients with gastric cancer. The aim of this study was to determine the survival rates and the effective factors in the patients with gastric cancer.

The study population included all the patients diagnosed with gastric cancer in Hamadan Province who were referred to Hamadan Imam Khomeini Specialized Clinic between 2004 to 2017. Patients were followed up by periodical referrals and/or telephone contact. The survival rate of the patients was calculated using Kaplan-Meier method and effective survival factors with Cox proportional regression. Data were analyzed using SPSS 23 software at a significance level of 0.05.

Out of the 350 patients with gastric cancer, 74.3% were male and 25.7% were female. One-year, three-year and five-year survival rates were 67%, 36% and 27%, respectively. The log -rank test showed that age, type of tumor, stage of disease, type of Surgery and metastasis of the disease were effective on the survival of patients. In Cox's multivariate analysis, the only age variables at the time of diagnosis and chemotherapy were survival variables. (P<0.05).

The results of this study showed that age variable is a strong factor in survival, so it is essential to diagnose the disease at the early age and early stages of the disease using a screening program.

Regular exercise training is a useful strategy to reduce inflammatory markers, but it is still unclear what type of training is better. Thus, this study compared the effects of 12-week of low-intensity resistance (Low-RT) and high-intensity interval aerobic training (High-IAT) on serum interleukin (IL)-6 levels and insulin resistance (IR) markers in obese and young men.

In this quasi-experimental study, 38 obese and young men (age = 28.4 ± 5.2 years and body fat% = 27.5 ± 1.5) randomly assigned into a low-RT (n=14), high-IAT (n=12) and control (CON, n=12) groups. An age-matched control group of non-obese men (age = 27.0 ± 5.9 years, body fat% = 15.5 ± 2.6 and n=15) were also recruited for baseline comparison. Subjects performed the training programs (Low-RT: 10 exercises at 30-50% of 1-repetition maximum, and High-IAT: 16-minute of interval running at 80-90% of maximum heartbeat with a 3-minute recovery between intervals) for 12 weeks and 3-day a week. Data analyzed using SPSS version 18.

The independent t-test showed that the concentrations of glucose (P = 0.01), insulin (P = 0.04) and IR-index (P = 0.02) in obese men was higher than the non-obese at baseline, but no significant difference was noted for IL-6 (P = 0.14). The 2-factor analysis of variance revealed that insulin and IR-index similarly and remarkably decreased in response to the training (P < 0.05), but remained unchanged with glucose and IL-6 (P > 0.05).

In summary, insulin resistance markers in the obese men group were higher than in the non-obese men group, but no significant difference was detected in IL-6 in these groups. Insulin and IR-index decreased remarkably and similarly after training programs, but no significant changes were found in glucose and IL-6.

Due to preventing unnecessary exposure to x-ray, the dentists must acquire adequate information about radiography.

This descriptive cross-sectional study was conducted on general dentists working in Yazd City, selected by convenience sampling method. The data were collected using a three-part questionnaire, the first part included demographic information of the dentists (age, gender, work experience, education level), and the second part contained the effective clinical findings in radiography (patient age, sex, history, radiographic costs, patient preferences, clinical observations, type of radiographic imaging system).

120 dentists with an average age of 37.38 ± 9.88 were in this study. The greatest impact factors on decision making by dentists in prescribing radiography were: surgical treatment plan (87.5%), toothache (75%), poor oral hygiene and heavily restored dentition (73.3%) and those who afraid of X-ray exposure were the least effective factors. The top radiographic choice of most of the dentists for diagnosis of occlusal caries was periapical radiograph, with 55%, even though according to the existing researches bitewing radiography would be the effective method. The top choice for the diagnosis of interdental caries was bitewing radiography with 88.3%, which matched the existing researches.

Based on the results of this study, it can be said that the dental community has little knowledge in the field of radiography for the diagnosis of occlusal carieshowever most of the dentists were right about diagnosing interdental caries. Therefore, it is important to hold retraining courses in order to maintain and improve the level of awareness of dentists and their familiarity with the latest radiographic techniques.

Prevention and management of pain is one of the major challenges in the neonate intensive care units. The aim of this study was to evaluate the effect of breast-milk and leg massage on the intensity pain from painful procedures such as heel stick.

This study was a randomized clinical trial aimed to compare the effect of breast-milk and leg massage on neonate’s pain intensity during heel-blood sampling in neonatal care unit of Tehran Fayazbakhsh Hospital, Iran in 2016. Neonates were divided into two groups of 15, based on randomly number schedule. In the first group, first massage, then heel stick was performed, after 12 hours of wash out period, breast feeding intervention was performed and then blood sampling was done from the other heel. In the second group, the intervention group, the action had done opposite. The neonates were laid in the supine or lateral position, at the same time as bleeding was started, filming of the faces and organs of the infant was carried out by a researcher's colleague and it continued only two minutes after the bleeding was completed.Videos were viewed by two senior specialist babies and the pain intensity was determined based on the NIPS scale. The data were fed into the SPSS 20 software and descriptive and analytic statistics were applied for data analysis.

The mean of the statistical Wilcoxon signed Ranks Test showed that there was a significant difference for pain score during (p<0/001), and after the intervention of each of the two groups (p<0/0001).

Based on the result of study, nurses can use leg massage to decrease the pain during painful procedures relevant to newborns instead of breast-milk.

Glucose-6-phosphate dehydrogenase deficiency is the most common enzyme disorder. This enzyme involved in maintaining the balance of active oxygen species and its defect causes oxidative damage. PON1 is an HDL-based glycosylated protein that prevents lipid peroxidation. In this study, the prevalence of PON L55M polymorphism in paraoxonase enzyme in neonates with a deficiency in G6PD activity was evaluated, and the level of oxidative stress was measured.

 In the present case-control study, 60 infants 2 to 6 months with G6PD enzyme activity deficiency and 60 healthy infants identical in age was selected. Polymorphism examination was done using PCR-RFLP technique, and oxidative stress parameters were measured by spectrophotometry. Chi square and t test statistical analysis of data was performed using SPSS V16 software.

The frequency of genotype LL, LM and MM for PON1 L55M was 43.33%, 43.3% and 13.3% and, 35%, 21.6% and 43.3% in control and case group, respectively. Genotypic frequency of LM and MM was significant between control and control groups (P <0.05). The allele frequency between L and M was also significant (P <0.05). Superoxide dismutase enzyme activity and mean carbonyl level comparison did not show a significant difference (P >0.05), but the activity of catalase enzyme and mean level of thiol was showed a significant difference (P <0.05).

In the present study, the frequency of LM genotype in neonates with G6PD deficiency was significantly different in comparison to the control group. This frequency is consistent with the results obtained from oxidative stress conditions (significant reduction in the level of thiol and catalase activity).

Aging is a natural phenomenon that is caused by changes in the cells of the body. Theoretically, aging starts from birth and lasts throughout life. These changes affect the function of the cells. Also, in old tissues, the capacity for homeostasis and tissue repair is decline due to destructive changes in specific tissue stem cells, niche of stem cells and systemic factors that regulate stem cell activity. Understanding molecular pathways that disrupt stem cell function during aging is crucial for the development of new treatments for aging-associated diseases. In this article, the symptoms of stem cell aging and the key molecular pathways that are commonly used for the aging of stem cells were discussed. We will consider experimental evidence for all of the mechanisms and evaluate the way that can slow down or even stop the aging process. Finally, we will look at the aging process of three types of stem cells.