Iranian Journal of Medical Sciences
Volume:45 Issue: 4, Jul 2020

Nearly every 100 years, humans collectively face a pandemic crisis. After the Spanish flu, now the world is in the grip of coronavirus disease 2019 (COVID-19). First detected in 2019 in the Chinese city of Wuhan, COVID-19 causes severe acute respiratory distress syndrome. Despite the initial evidence indicating a zoonotic origin, the contagion is now known to primarily spread from person to person through respiratory droplets. The precautionary measures recommended by the scientific community to halt the fast transmission of the disease failed to prevent this contagious disease from becoming a pandemic for a whole host of reasons. After an incubation period of about two days to two weeks, a spectrum of clinical manifestations can be seen in individuals afflicted by COVID-19: from an asymptomatic condition that can spread the virus in the environment, to a mild/moderate disease with cold/flu-like symptoms, to deteriorated conditions that need hospitalization and intensive care unit management, and then a fatal respiratory distress syndrome that becomes refractory to oxygenation. Several diagnostic modalities have been advocated and evaluated; however, in some cases, diagnosis is made on the clinical picture in order not to lose time. A consensus on what constitutes special treatment for COVID-19 has yet to emerge. Alongside conservative and supportive care, some potential drugs have been recommended and a considerable number of investigations are ongoing in this regard.

Pulmonary dysfunction is one of the critical complications of a stroke. However, it remains unclear whether the mechanism is caused by either neurogenic or inflammatory reactions. The present study aimed to determine the effect of cerebral ischemia-reperfusion injury and the role of the vagus nerve on hypoxic pulmonary vasoconstriction (HPV) in rats. This study was performed at Shiraz University of Medical Sciences, Shiraz, Iran, 2018. Male Sprague Dawley rats (n=56) were divided into four groups, namely the sham, vagotomy (Vag), 1 hour of ischemia followed by 23 hours of reperfusion without vagotomy (I/R) and with vagotomy (I/R+Vag). Neurological deficit scores and total infarct volumes of brains were measured in the I/R and I/R+Vag groups. Pulmonary artery pressure and lung weight were continuously registered during ventilation with normoxic and hypoxic gases in the isolated lungs. The blood gas parameters and the lung malondialdehyde (MDA) level of each group were also evaluated. ANOVA, with Tukey’s post hoc test and t test, was used to compare the variables in the experimental groups. The infarct volume of the brains in the I/R and I/R+Vag groups were similar. HPV in the I/R group was lower than those in the sham and Vag groups, while vagotomy reversed this response in the I/R+Vag group (P=0.004). In the I/R group, PO2 and pH were lower, and PCO2 was higher than those in the sham and Vag groups. The lung MDA level in the I/R group was higher than that in the Vag group (P=0.019). Brain ischemia-reperfusion injury decreased HPV independent of increased MDA in the lung, whereas vagotomy improved HPV by repairing the blood-gas barrier and oxygen sensing.

Language disorders may affect receptive and/or expressive language skills. The use of a validated and reliable assessment tool is essential to assess these skills in children. The present study aimed to develop a valid and reliable language development instrument for Persian-speaking children aged 2-6 years. The present cross-sectional study was conducted during 2016-2017 in three main Iranian cities, namely Mashhad, Tehran, and Isfahan. The target population was children between the ages of 2 and 6 in various kindergartens and schools. The Persian Language Development Scale (PLDS) was developed by incorporating linguistic characteristics of the Persian language and Iranian culture. Following a number of iterations, including a pilot study of 36 children, the final version of the PLDS tool was used to assess the receptive and expressive language skills of 460 children. The reliability and validity of the PLDS tool were examined. The content validity ratio (CRV) of the PLDS tool was 0.85. The tool could differentiate children by age, but not by sex. The test-retest reliability, with 10 days interval, showed a significant correlation between the coefficients of receptive (0.96) and expressive (0.93) scales. The intraclass correlation coefficient (ICC) for receptive and expressive scales was 0.93 and 0.98, respectively. The internal consistency, using the KR-21, for the receptive and expressive scales was 0.88 and 0.92, respectively. A language development scale has been developed to assess receptive and expressive language skills in Iranian children aged 2-6 years. The validity and reliability of the tool were confirmed.

Mesenchymal stem cells (MSCs) are widely used to treat various diseases, however, their proliferative potential reduces after a number of passages. It has been shown that some probiotics such as Bifidobacterium bifidum (B. bifidum) affect the proliferation of various cell lineages. The present study aimed to investigate the effect of B. bifidum on the proliferation of rat bone marrow stromal cells (rBMSCs) and to develop a method for compensating their proliferation reduction after some passages. The present experimental study was conducted at Tehran University of Medical Sciences, Tehran, Iran, in 2017. The stromal cells were isolated from rBMSCs and their mesenchymal properties were confirmed by osteogenic and adipogenic differentiation media and staining. B. bifidum was cultured and the B. bifidum supernatant (BS) and bacterial cell mass (BCM) were extracted. The rBMSCs were treated with different concentrations of BS and BCM. The MTT assay was performed to measure the number of viable cells in the culture. Cell proliferation was analyzed using the paired-sample t test. Cell proliferation increased as the concentration of bacteria was increased logarithmically (0, 0.1, 0.3, 0.9, 3, 9, 30 μL/mL). In comparison with BS, cells treated with BCM showed increased cell proliferation at lower concentrations. This effect was caused by removing the “de Man, Rogosa, and Sharpe” (MRS) broth medium from the BCM culture. The optimal concentration of bacteria with the most significant effect on rBMSCs proliferation was determined. A significant increase in the proliferation of stromal cells was observed; confirming the stimulatory potential of probiotics (B. bifidum) on various cells. The use of products containing probiotic bacteria can increase the proliferation potential of BMSCs.

Microbial plaque-induced oral diseases are among the most common diseases worldwide. The present study aimed to compare the antimicrobial effect of electrolyzed water (EW), (acidic, mildly basic, and basic) on the growth of bacterial species producing dental plaque and to assess their cytotoxicity on fibroblasts and epithelial cells. The study was performed at Shahid Beheshti University of Medical Sciences in 2019. Several bacterial species (Streptococcus salivarius, Staphylococcus aureus, Lactobacillus casei, and Aggregatibacter actinomycetemcomitans) were treated with different EW types at three pH values (3, 9, and 11) for 30 seconds and subsequently, the colonies were counted. The cytotoxic effect of these EW types was evaluated on HeLa and L929 cell lines at 30 seconds, 1 minute, and 5 minutes. GraphPad Prism 6.0 was used for statistical analysis. The Kruskal-Wallis test followed by Mann-Whitney U and one-way analysis of variance followed by Tukey’s test were used to analyze bacterial activity and cell cytotoxicity, respectively. P<0.05 was considered statistically significant. EW types significantly inhibited bacterial growth at all pH values. The strongest antibacterial activity of EW was against A. actinomycetemcomitans (P<0.001) and the least significant antibacterial activity was against S. aureus (P<0.001). The EW types showed increased cytotoxic activity against L929 cells as the treatment time increased. The most cytotoxic effect was seen at 5 minutes of treatment in all EW types compared with the negative control group (P<0.0001). This negative cytotoxic effect on HeLa cells was shown just after 30 seconds and viable cell counts increased over time, reaching its highest value at 5 minutes of treatment with basic EW (P<0.0001). The contradictory effects of the EW types on both HeLa and fibroblasts, in addition to variable results at different exposure times, indicated that the effect of EW could vary depending on cell types and treatment periods.

Leishmaniasis is the most important parasitic disease in Iran and is the third highest rate of rural cutaneous leishmaniasis in the world. Chitosan-polyethylene oxide nanocomposite fibers can be a suitable replacement for ordinary bandages. For the first time, in the absence of any published reports, the present in vitro study aimed to evaluate the anti-leishmanial effects of chitosan (CS)-polyethylene oxide (PEO)-berberine nanofibers on Leishmania major. The present experimental study was conducted in 2018 in Tehran, Iran. The CS-PEO nanofibers containing berberine, as a natural anti-parasitic agent, were prepared using the electrospinning technique. Biocompatibility and fibroblast proliferation on nanofibers were investigated. In addition, the anti-leishmanial activity of CS-PEO nanofibers in both the promastigote and amastigote stages of Leishmania major was evaluated after parasite vital staining and MTT assay and compared to a control group. Statistical analysis was performed using SPSS software (version 18.0). Statistically significant differences were determined using the one-way ANOVA. The Duncan and Dunnett post hoc tests were used for within-group comparisons. P<0.05 was considered statistically significant. The results showed that nanofiber scaffolds with a mean diameter of 77.5±19.5 nm were perfect, regular, bead-free, and non-toxic, on which fibroblast cells grew well and proliferated. In addition, the optical density indicated that berberine 20% (w/v) significantly prevented promastigotes growth (IC50=0.24 μg/mL) and amastigotes death (IC50=0.91 μg/mL) compared with other concentrations and the control group. The study on the cytotoxic effects showed that CS-PEO-berberine nanofibers had strong lethal effects on Leishmania major in promastigote and amastigote stages in vitro. Further studies are required to investigate the effects of this nanofiber on leishmanial ulcers in laboratory animals and clinical cases.

Escherichia coli (E. coli) is the most common cause of urinary tract infection (UTI) and typically treated with antibiotics. Unrestricted use of antibiotics may lead to the emergence of antibiotic-resistant bacteria. The present study aimed to isolate and characterize phages against E. coli from infected urine samples and to determine the lytic activity of phages against E. coli in vitro.

The present experimental study was conducted in the Laboratory of Bouali Sina Hospital (Sari, Iran) in May 2018. E. coli was identified from nine urine samples of patients with UTI using conventional microbiological methods. Bacteriophages were isolated from the infected urine specimens, and their lytic activity was determined using the spot test. The titer of the bacteriophages was measured using the double-layer agar technique. The morphology of the bacteriophages was revealed using transmission electron microscopy, and the latent time period and burst size were determined. Data were analyzed using the SPSS software package.

E. coli was isolated from nine infected urine samples. The lytic activity of bacteriophages against E. coli was determined using the spot test by observing the formation of inhibition zones. Transmission electron microscopy showed E. coli phages belonging to the Myoviridae family. The latent time period was 20 minutes with a burst size of 1,200 plaque-forming unit (PFU) per infected cell. The results of the double-layer agar assay showed that the titer of bacteriophages was 20×108 PFU/mL.

The E. coli bacteriophage was isolated from infected urine samples and characterized, and their lytic activity against E. coli was determined in vitro.

Acute lymphoblastic leukemia (ALL) is the most common cause of cancer-related fatality among children. This study aimed to identify the significant prognostic factors for the incidence of pediatric ALL. This retrospective study, conducted from 2007 to 2016 in the Iranian city of Mashhad, enrolled 417 patients with ALL. The diagnosis was confirmed by Giemsa staining of bone marrow smears. The first recurrence was regarded as the event of interest and non-relapse mortality as the competing event through a three-parameter Gompertz model. The level of statistical significance for univariate and multivariate analyses was set at 0.2 and 0.05, respectively. The first recurrence occurred in 44 (10.6%) survivors. Disease-free survival and 5-year overall survival rates were 85.9% and 74%, correspondingly. The five-year incidence rate for the first recurrence was 11.5% in the presence of non-relapse mortality. Briefly, the characteristics of the Gompertz model conferred more effective prognostic factors. Age above 10 years (P=0.010), involvement of the central nervous system (P=0.050), a high white blood cell count (P=0.020), and tumor lysis syndrome (P=0.010) were the significant prognostic factors for the recurrence and mortality of ALL. Accordingly, careful monitoring in the administration of treatment protocols is suggested to reduce the risk of recurrence and death in these patients.