Distribution of bacterial contamination in a teaching hospital in Tehran - a special focus on Staphylococcus aureus

There are documents that confirm the cycle of bacterial transmission between patients, staff, and the inanimate environment. The environment may have more effect on intensive care units (ICUs), because the patients who require intensive care have unstable clinical conditions and are more sensitive to infections. The aim of this study was to determine the prevalence of bacteria in air and inanimate surface in the ICUs and to compare the microbial levels to standard levels.Air and inanimate surface in the four ICUs of a teaching hospital underwent weekly surveillance by means of air sampler and swabs for a period of six-month. Total bacterial counts were evaluated onto trypticase soy agar and mannitol salt agar (MSA).A total of 725 samples [air (168) and inanimate surfaces (557)] were collected. The total mean ± SD CFU/m3 of airborne bacteria in all of the ICUs were 115.93 ± 48.04. The most common bacteria in air of the ICUs were Gram-positive cocci (84.2%). The total mean ± SD airborne of Staphylococcus aureus was 12.10±8.11 CFU/m3. The highest levels of S. aureus contamination were found in ventilators and bed ledges. More suitable disinfection of hospital environments and monthly rotation in utilization of the various disinfectant agents are needed for the prevention of airborne and inanimate transmission of S. aureus.     

Analysis and Design of an Object-Independent Superlens

A new design for the multilayer superlens, with the sub-wavelength imaging ability for various 2D objects in the visible range, is introduced and analyzed. The designed superlens will be more versatile for practical applications. A rigorous and efficient approach based on the method of moments is used to study the imaging performance of this structure. The imaging performance of the proposed superlens is evaluated using the correlation coefficient. In this work, the closed-form dyadic Green’s functions in spatial domain, needed for the method of moments solutions, are obtained by applying the complex image method. Besides, the numerical integration is exploited to verify this method. The imaging results obtained via our approach are examined by comparison with the finite element method simulations that reveal good efficiency and accuracy of the proposed method.     

The Association Between Effective Dose of Magnesium and Mild Compulsive Exercise on Spatial Learning,Memory, and Motor Activity of Adult Male Rats

The relationship of minerals and trace elements with inflammatory bowel disease (IBD) is complex. Alterations in their metabolism can be induced by the diseases and their complications. To study the role of trace elements in IBD patients’ serum zinc and copper and their related enzymes, including superoxide dismutase (SOD), activity were measured in patients with IBD patients as well as in healthy subjects. In addition, the correlation between serum trace element levels, albumin, total protein, urea level, copper/zinc ratio, and disease activity (DA) was determined in these subjects. Serum samples were obtained from 35 patients (19 ulcerative colitis (UC) and 16 Crohn’s disease (CD)) in the active phase of the disease and 30 healthy control subjects. Serum levels of zinc, copper, SOD activity, albumin, total protein, and urea were measured. The results were compared between the two groups using independent Student’s t test in statistical analysis. Serum levels of zinc, SOD activity, albumin, and total protein were significantly lower (P < 0.05) in patients than controls, while serum urea level was significantly higher in patients compared to controls. Copper concentrations did not differ between patients with IBD (mean ± SD, 58.8 ± 20.7 μg/d) and controls (55.57 ± 12.6 μg/d). Decreased levels of zinc and SOD activity are associated with increased inflammatory processes indicating inappropriate antioxidant system in patients with IBD. Additionally, lower levels of albumin and total protein with higher level of urea reflect metabolic problems in liver system.     

Motor Neuron Transdifferentiation of Neural Stem Cell from Adipose-Derived Stem Cell Characterized by Differential Gene Expression

Adipose-derived stem cells (ADSC) are adult stem cells which can be induced into motor neuron-like cells (MNLC) with a preinduction-induction protocol. The purpose of this study is to generate MNLC from neural stem cells (NSC) derived from ADSC. The latter were isolated from the perinephric regions of Sprague–Dawley rats, transdifferentiated into neurospheres (NS) using B27, EGF, and bFGF. After generating NSC from the NS, they induced into MNLC by treating them with Shh and RA, then with GDNF, CNTF, BDNF, and NT-3. The ADSC lineage was evaluated by its mesodermal differentiation and was characterized by immunostaining with CD90, CD105, CD49d, CD106, CD31, CD45, and stemness genes (Oct4, Nanog, and Sox2). The NS and the NSC were evaluated by immunostaining with nestin, NF68, and Neurod1, while the MNLC were evaluated by ISLET1, Olig2, and HB9 genes. The efficiency of MNLC generation was more than 95 ± 1.4 % (mean ± SEM). The in vitro generated myotubes were innervated by the MNLC. The induced ADSC adopted multipolar motor neuron morphology, and they expressed ISLET1, Olig2, and HB9. We conclude that ADSC can be induced into motor neuron phenotype with high efficiency, associated with differential expression of the motor neuron gene. The release of MNLC synaptic vesicles was demonstrated by FM1-43, and they were immunostained with synaptophysin. This activity was correlated with the intracellular calcium ion shift and membrane depolarization upon stimulation as was demonstrated by the calcium indicator and the voltage-sensitive dye, respectively.     

The Effects of Soy Milk Enriched with Lactobacillus casei and Omega-3 on the Tibia and L5 Vertebra in Diabetic Rats: a Stereological Study

Bone fragility, despite relatively high BMD values, is an important complication related to insulin resistance and oxidative stress in diabetes mellitus type 1. The present study aimed to compare the effects of soy milk (SM), soy milk containing Lactobacillus casei (PSM), and soy milk enriched with Lactobacillus casei and omega-3 (OPSM) on the stereology of the tibia and vertebra, and antioxidant activity in type 1 diabetic rats. Sixty-five male Sprague Dawley rats were randomly assigned into 5 groups of 13 animals each. Diabetes was induced by a single injection of STZ (60 mg/kg); two control groups (non-diabetic: CN and diabetic: CD) were selected and then fed with 1 mL of distilled water. Three treatment groups were fed 1 ml of SM, PSM, and OPSM via intragastric gavage for 60 days. Treatment with SM, PSM, and OPSM significantly decreased (P < 0.05) the number of the osteoclasts in both tibia and L5 vertebra, and plasma alkaline phosphatase level. Also, the osteoblast number, calcium level, catalase activity, and total antioxidant capacity were increased in the SM, PSM, and OPSM groups compared to the STZ group. OPSM had the greatest effects on the stereological and biochemical parameters compared to the SM and PSM groups. Soy milk combination with Lactobacillus casei and omega-3 can ameliorate the stereological changes in the tibia and vertebra. In addition, this combination increased the antioxidant activity and improved the redox homeostasis in diabetic rats. These results suggest the potential role of soy milk containing Lactobacillus casei enriched with omega-3 in preventing and delaying osteoporosis in diabetic patients.

     

Prevalence of ESBL and MBL encoding genes in Acinetobacter baumannii strains isolated from patients of intensive care units (ICU)

The aim of this study was to investigate the prevalence of ESBL and MBL encoding genes among A. baumannii isolates. In this cross sectional study, 100 A. baumannii strains were isolated from ICU wards of 3 educational hospitals of Hamadan City, Iran in 2011. Phenotypic identification of the production of ESBLs and MBLs has been carried out by using E-test and DDST methods, respectively. PCR technique was used for amplification of the ESBL and MBL encoding genes, namely: CTX-M, SHV, TEM, OXA-51, VIM-Family, IMP-Family, SPM-1, SIM-1, and GIM-1. Eighty seven (87%), 95 (95%), 98 (98%) and 95 (95%) out of 100 A. baumannii isolates were resistant to imipenem, meropenem, ceftazidime and cefotaxime, respectively. Also, 99% and 7% of the isolates were MBLs and ESBLs produced phenotypically. Thirty (30%), 20 (20%) and 58 (58%) out of 100 A. baumannii isolates have been confirmed to harbor the bla_VIM-family, TEM and SHV genes, respectively. Our results show no significant relationship between the detected gens with production of MBLs and ESBLs in spite of high prevalence of MBL encoding and drug resistant A. baumannii. Probably some other genes rather than what we studied are involved in phenotypic production of MBLs and ESBLs and subsequent drug resistance in Hamadan area, Iran.     

Osteogenic differentiation of preconditioned bone marrow mesenchymal stem cells with lipopolysaccharide on modified poly-l-lactic-acid nanofibers

Tissue engineering is an interdisciplinary expertise that involves the use of nanoscaffolds for repairing, modifying, and removing tissue defects and formation of new tissues. Mesenchymal stem cells (MSCs) can differentiate into a variety of cell types, and they are attractive candidates for tissue engineering. In the current study, the electrospinning process was used for nanofiber preparation, based on a poly-l -lactic-acid (PLLA) polymer. The surface was treated with O ₂ plasma to enhance hydrophilicity, cell attachment, growth, and differentiation potential. The nanoscaffolds were preconditioned with lipopolysaccharide (LPS) to enhance induction of differentiation. The nanoscaffolds were categorized by contact angle measurements and scanning electron microscopy. The MTT assay was used to analyze the rate of growth and proliferation of cells. Osteogenic differentiation of cultured MSCs was evaluated on nanofibers using common osteogenic markers, such as alkaline phosphatase activity, calcium mineral deposition, quantitative real-time polymerase chain reaction, and immunocytochemical analysis. Based on the in vitro results, primed MSCs with LPS on the PLLA nanoscaffold significantly enhanced the proliferation and osteogenesis of MSCs. Also, the combination of LPS and electrospun nanofibers can provide a new and suitable matrix to support stem cells’ differentiation for bone tissue engineering.     

Effect of curcumin on glioblastoma cells

Curcumin is a polyphenolic compound derived from Curcumin longa L. There are growing bodies of evidence revealing the antitumor effect of curcumin in different tumors; although the molecular mechanism behind this inhibition in glioblastoma multiform (GBM) still remains unclear. Here we investigated the antitumor activity of nano micelles curcumin compared with erlotinib in U-373 cells in monolayer cell cultures and spheroids models. Furthermore, we characterized affecting cell cycle perturbation, as well as apoptosis induction in GBM cells. The antiproliferative activity of nano micelles curcumin and erlotinib were assessed in monolayer and spheroid models. The influence of the cell cycle and expression levels of nuclear factor κB (NF-κB) and Wnt/β-catenin pathway was checked. Nano micelles curcumin suppressed cell growth in U-373 cells via modulation of Wnt and NF-κB pathways. Moreover, cells developed an early G2/M cell cycle arrest followed by sub-G1 apoptosis and apoptotic bodies formation posttreatment with nano micelles curcumin and erlotinib. In the core signaling pathways of GBM, nano micelles curcumin either significantly influences the NF-κB pathway by decreasing p-65 expression or significantly inhibits the Wnt/β-catenin pathway by declining cyclin D1 expression. In conclusion, we have shown that nano micelles curcumin effectively prevent proliferation, and invasion of GBM cells through perturbation of Wnt/β-catenin and NF-κB pathways, suggesting further investigations on the therapeutic application of this novel anticancer drug in in vivo models.     

Ultrasensitive DNA sensor based on gold nanoparticles/reduced graphene oxide/glassy carbon electrode

We have designed a simple and novel electrochemical biosensor based on glassy carbon electrode (GCE) for DNA detection. GCE was modified with reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) by the electrochemical method, which is helpful for immobilization of thiolated bioreceptors. The electrode modification processes were characterized by scanning electron microscopy (SEM) and electrochemical methods. Then a single-stranded DNA (ssDNA) probe for BRCA1 5382 insC mutation detection was immobilized on the modified electrode for a specific time. The experimental conditions, such as probe immobilization time and target DNA (complementary DNA) hybridization time and temperature with probe DNA, were optimized using electrochemical methods. The electrochemical response for DNA hybridization and synthesis was measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) methods. The calibration graph contains two linear ranges; the first part is in the range of 3.0 × 10⁻²⁰ to 1.0 × 10⁻¹² M, and the second segment part is in the range of 1.0 × 10⁻¹² to 1.0 × 10⁻⁷ M. The biosensor showed excellent selectivity for the detection of the complementary sequences from noncomplementary sequences, so it can be used for detection of breast cancer.