نشریه دانشور پزشکی
پیاپی 162 (آذر و دی 1401)

As an important factor in pathogenicity, the ability of Staphylococcus aureus to produce biofilm increases its stability in the environment and living host. Biofilms formed by S.aureus, especially those related to the implant of medical devices, can act as a physical barrier against antibiotics and the host's immune system, leading to chronic or persistent infections. Hence, implementation of efficient diagnostic tests for the detection of biofilm formation can help reduce the disease burden. The purpose of this study was to assess different methods for the detection of biofilm formation in 40 S.aureus isolates.

A total of 40 non-duplicate S. aureus clinical isolates were identified. Biofilm formation was detected by Tissue Culture Plate (TCP), tube method (TM) and Congo red agar (CRA) methods and PCR assay was used to detect icaA and icaD genes. 

Among all S. aureus isolates, 21(52.5%) contained both icaA and icaD genes and icaD gene was present in all biofilm positive isolates. Tissue culture plate, Congo red agar, and tube method detected 30%, 42.5%, and 67.5% biofilm formation isolates, respectively.

According to the results, tissue culture plate with supplemented glucose showed the best correlation with the results of molecular assay and can be used as a reliable method to detect biofilm formation in clinical isolates of S. aureus.

With the contagion of the deadly and infectious disease of Corona virus known as Covid-19, many universities and training centers suspended face-to-face teaching. The present study was designed and conducted to investigate the attitudes of medical and dental students of Shahed University towards virtual education during Covid-19 epidemic

This descriptive-analytical cross-sectional study was performed on 300 medical and dental students of Shahed University in 2021. Data were collected using a valid and reliable E-learning opportunities and threats questionnaire and entered in SPSS 21 software. Linear regression method was used to analyze the data.

The average attitude of students towards virtual education in the cost-learning efficacy dimension was 22.17±6.71, mental-emotional dimension was 25.83±5.08, communicational instructor-student dimension was 18.25 ± 5.08 and the total attitude score was 66.15±13/69. There was a direct significant correlation between cost-effectiveness and factors related to teaching-learning with the total attitude score (P=0.001).

The general attitude of students towards virtual education is related to the dimensions of cost-learning efficacy of education and factors related to teaching-learning. These two factors together can make 81.4% of the changes in the attitude score.

Myelin-producing oligodendrocytes play an important role in supporting neuronal function in the mammalian nervous system. The formation of myelogenous oligodendrocytes from the ancestral oligodendrocyte cells requires the activity of a group of transcriptional regulators that are essential for the synthesis of myelin components. The aim of the present study was to investigate the effect of moderate intensity continuous training (MCT) on myelin-based protein (MBP) and myelin proteolipid (PLP) indices associated with myelination in the frontal cortex of rats.

16 male Wistar rats were randomly divided into two equal groups of control and continuous training. The exercise program consisted of 24 minutes of continuous running on a treadmill for 8 weeks (5 sessions per week). At the end of the training period, the forehead cortex of rats was extracted to evaluate changes in gene expression. Data were analyzed using statistical methods of analysis of covariance and Mann-Whitney at a significant level (α≤0.05).

The results showed that continuous training significantly increased the expression of MBP and PLP genes in comparison with the control group.

It can be said that continuous moderate intensity training can be useful in accelerating the myelination process in the cerebral cortex and can be considered as a non-invasive method in this field.

Multiple Sclerosis (MS) is an autoimmune disease in which muscle weakness and fatigue reduce the quality of life. Therefore, the aim of this study was to investigate the effect of two types of Pilates exercises at home and outdoors on fatigue and quality of life in MS patients.

Among the women, 44 women with MS were randomly selected and divided into three groups: home-based training, out-door training and control group. The exercise groups performed Pilates exercises for 8 weeks individually (via DVD) at home and under the sun exposure between 8 and 10 am, but the control group did not do any exercise during this time. Fatigue severity, quality of life and vitamin D levels of patients were measured before and after exercise and data were analyzed using covariance statistical method.

The results showed that after eight weeks of training, there was a significant difference between the indicators of fatigue, quality of life and vitamin D serum in women with MS in all three groups (P≤0.05). The results of post-test post hoc test showed that there was a significant difference between the two training groups in all three indices (P≤0.05). Also, eight weeks of outdoor training compared to home training caused a greater increase in serum vitamin D (78.43%). And quality of life (50.26%) and further reduction in the severity of patients' fatigue (41.76%) (P≤0.05).

Pilates training is recommended for people with MS due to its low cost, availability, and significant effects on quality of life and vitamin D and fatigue.

Obesity is associated with dyslipidemia, which leads to elevated triglyceride levels, apoptosis and compromised cardiac function. The aim of this study was to investigate the effect of aerobic training (AT) and royal jelly (RJ) on apoptosis indices in cardiomyocytes in high-fat diet-induced obese rats.

In this experimental study, 45 male rats were randomly divided into five groups (n=9): Normal Diet (ND), High-Fat Diet (HFD), High-Fat Diet+Training (HFDT), High-Fat Diet+Royal Jelly (HFDRJ), and High-Fat Diet+Training+Royal Jelly (HFDTRJ). The supplement groups received 100 mg of royal jelly (kg/body weight) diluted in distilled water orally during the intervention period. The aerobic exercise program included treadmill running with an intensity of 50-60% oxygen consumption (VO2max), 5 days/week for 8 weeks. Data were analyzed using ANOVA at p<0.05.

HFD decreased Bcl2 (p=0.006), increased BAX (p=0.006) and BAX/Bcl2 (p=0.006). AT, RJ as well as the combination of AT with RJ increased Bcl2 and decreased BAX and BAX/Bcl2 (p≤0.05). Increase in Bcl2 and decrease in BAX and BAX/Bcl2 were significant in HFDTRJ group compared to HFDT and HFDRJ groups (p≤0.05).

Combining AT with RJ may improve apoptotic markers in cardiomyocytes by affecting BAX and Bcl2 expression and control HFD-induced cardiomyocytes damage on the apoptotic pathway.

Type 3 diabetes or brain diabetes is a term for Alzheimer, which insulin resistance selectively affects brain and causes cognitive loss. Wnt signaling pathways play role in nervous system, reducing symptoms of Alzheimer's disease, insulin synthesis and diabetes. Although positive effect of physical activities in diseases has been reported, the comparison of types of exercises has been less investigated. The aim of this study was to compare the effect of voluntary in an enriched environment and forced exercise on Wnt-5a expression and Aβ in hippocampus of type3 diabetic rats.

25 rats were divided into 5 groups: healthy control, sham, diabetes3, diabetes3+voluntary exercise in rich environment, diabetes3+forced exercise. Type3 diabetes was induced by intraventricular injection of streptozocin and the model was confirmed by behavioral test. The protocol was done during eight weeks. Wnt-5a expression was done by western blot method and Aβ accumulation was done by thioflavin S staining. Data analysis was done by ANOVA and Tukey's post hoc test (P≤0.05).

Two exercise group had a significant increase in expression of Wnt-5a in hippocampus (P≤0.05). In the comparison between exercise groups, the expression of Wnt-5a increased more in rich environment rats. The accumulation of Aβ in exercise groups was significantly reduced (P≤0.05) compared to the type 3 diabetes group, which was greater in the rich environment.

Forced and voluntary exercises by activating Wnt/β-catenin pathway in brain reduced accumulation of Aβ plaques. Rich environment has better effect in reducing the symptoms of patients compared to forced exercise, which may be due to reduced stressors in brain.

The reduction of effective motor proteins in axoplasmic transport is proposed as a possible reason for the occurrence of sarcopenia. The aim of the present study was determination of the effect of eight weeks of resistance training on amount of KIF5B protein in soleus and extensor digital longus (EDL) muscle tissue in aged male rats.

18 Aged and young male rats were randomly divided into 3 groups: aged resistance training, aged sham exercise and young sham exercise. The aged resistance training group climbed a one-meter ladder for eight weeks, 4 days a week, with one set and 8 repetitions, with a 2-minute rest interval between repetitions. To measure the amount of KIF5B protein, ELISA method was used, to measure the relative weight of muscles, a weighing scale was used, and to test the hypotheses, one-way analysis of variance and Tukey's post hoc test were used at the level of p≤0.05.

Following aging, the amount of KIF5B protein decreased significantly in soleus muscle and EDL compare to Young Sham group. Eight weeks of resistance training caused a significant increase in the amount of KIF5B protein in the soleus and EDL compared to the aged sham exercise. The Relative weight of both muscles in the resistance training group had a significant increase compared to the aged sham exercise.

Eight weeks of resistance training increases the amount of KIF5B protein in soleus and EDL muscles and their hypertrophy in aged male rats.

Mitochondrial disorder contributes to reduction of health, as well as onset and progression of the aging process. On the other hand, exercise enhances proteins, enzymes and mitochondrial function in human and animal samples. The present study aimed to evaluate eight-week moderate intensity continuous training (MICT) and high-intensity interval training (HIIT) on FOXO1 gene expression in the heart tissue of aged rats. 

In this experimental study, 24 old female rat (aging 16-18 months old, weighing 280-320 g) were randomly assigned into control (C), (MICT) and (HIIT) groups. HIIT exercises were performed with 85% to 110% VO2max intensity and 15-25 m/min speed; MICT exercises were conducted with 65% VO2max intensity and 25-25 m / min speed. Finally, the expression of FOXO1 gene was evaluated using Real time-PCR ΔΔ method and ΔΔCt formula. One-way analysis of variance with Tukey post hoc test in SPSS software version 22 were used to analyze the findings (p≤0.05). 

The results of the present study showed that compared to the control group, MICT significantly reduced the expression of FOXO1 gene in heart tissue (P=0.006). While HIIT had no significant effect on reducing FOXO1 gene expression (P=0.05). The results also showed a significant reduction in the level of gene expression in the MICT group compared to the HIIT group (P=0.03).

In comparison with HIIT, MICT exercises make the expression of FOXO1 gene in the heart tissue of aged laboratory white rats reduced. Controlling this protein can prevent excessive cardiac autophagy in elderly subjects.