Developing drug delivery systems based on alginate and brushite

Developing drug delivery systems based on alginate and brushit

Distribution of Enterotoxigenic Escherichia coli among E. coli isolates from diarrheal samples referred to educational hospitals in Tehran-Iran

Background: Introduction: Enterotoxigenic Escherichia coli (ETEC) is the most important bacterial cause of watery  travelers' diarrhea  in  developing countries. Watery diarrhea is can cause serious life-threatening dehydration. ETEC was caused diarrhea by the secretion of two heat-labile enterotoxins (LTs) and the heat-stable enterotoxins (STs) which increase intestinal secretion. Routine laboratory methods are not appropriate to detect ETEC and other diarrheagenic E. coli pathotypes. The molecular techniques such as PCR are rapid and accurate methods that have been developed for detection of ETEC. We were recognized ETEC by PCR on lt and st genes from E. coli isolates from patients with diarrhea collected from selected Tehran educational hospitals.Materials and Methods: The E. coli isolates were collected from total 140 patients with diarrhea and 110 patients without diarrhea using culture and IMViC test. DNA was extracted by boiling method and the presence of the uidA, lt and st genes was detected by PCR.Results: Among 140 E. coli isolates from diarrheal stools 5 (3.6%) isolates were positive for, just lt gene, 3 (2.1%) co-amplified for both lt/st and 1 (0.7%) was positive for just the st gene which were considered as ETEC. In the E. coli isolates from non-diarrheal control samples just one (0.9%) isolate was positive for both lt and st genes.Conclusion: The results showed that the ETEC as a significant cause of diarrhea, usually ignored by laboratories using traditional methods. Sometimes the ETEC causes severe diarrhea and can threaten for patient's life. Thus a rapid diagnostic test such as PCR can be very helpful in the treatment of patients

Study of Helicobacter pylori genotype status in cows, sheep, goats and human beings

BACKGROUND: Helicobacter pylori is one of the most controversial bacteria in the world causing diverse gastrointestinal diseases. The transmission way of this bacterium still remains unknown. The possibility of zoonotic transmission of H. pylori has been suggested, but is not proven in nonprimate reservoirs. In the current survey, we investigate the presence of H. pylori in cow, sheep and goat stomach, determine the bacterium virulence factors and finally compare the human H. pylori virulence factors and animals in order to examine whether H. pylori might be transmitted from these animals to human beings. METHODS: This cross- sectional study was performed on 800 gastric biopsy specimens of cows, sheep, goats and human beings. The PCR assays was performed to detection of H. pylori, vacA and cagA genes. The PCR products of Ruminant’s samples with positive H. pylori were subjected to DNA sequencing analysis. Statistical tests were applied for data analysis. RESULTS: Overall 6 (3%) cows, 32 (16%) sheep and 164 (82%) human beings specimens were confirmed to be H. pylori positive; however we were not able to detect this bacterium in all 200 goat samples. The vacA s1a/m1a was the predominant H. pylori genotype in all three kinds of studied population. There was 3.4–8.4% variability and 92.9-98.5% homology between sheep and human samples. CONCLUSIONS: Considering the high sequence homology among DNA of H. pylori isolated from sheep and human, our data suggest that sheep may act as a reservoir for H. pylori and in the some extent share the ancestral host for the bacteria with human

Cochlear Implants: An Excursus into the Technologies and Clinical Applications

Hearing loss causes severe alterations in social function and daily communications. Cochlear device implantation (CDI) is the only beneficiary method for auditory rehabilitation in patients with severe to profound sensorineural hearing loss (SNHL). Regarding a report in 2014, over 300,000 people had received cochlear implants throughout the world since December 2012 among which about 60,000 were adults and 40,000 were children in the United States. In this chapter, we discuss the history, origin, mechanism of action, and type of cochlear implants, as well as method of surgery and complications

Relationships between the Salivary Microbial Composition and Gastrointestinal Diseases

Abstract   Background and Objective: Salivary microbiota, including bacteria shed from oral surfaces, is individualized, temporally stable and affected by the environmental factors such as diet, lifestyle and oral hygiene. Salivary microbiota is nonpathogenic and commensal; however, if microbiota colonizes into the intestines, they could alter gastrointestinal microbiota and result in development of several chronic inflammatory diseases, foremost autoimmune diseases and gastrointestinal cancers. There are few studies that assessed salivary microbiota in autoimmune gastrointestinal disorders. This may help researchers find novel personalized therapeutic approaches for the gastrointestinal diseases. Therefore, the aim of this review was to discuss alterations of salivary microbiota composition in gastrointestinal disease progress, including celiac disease, inflammatory bowel disease and gastrointestinal cancers. Results and Conclusion: This study suggested that oral microbiota composition is linked to chronic inflammatory diseases by changing the immune system responses through increasing the production of inflammatory cytokines and mediators. Investigation of saliva microbiota is becoming an important part of diagnosing gastrointestinal diseases and changes in the composition of oral microbiota can predict risks of disorder progression in high-risk individuals. Conflict of interest: The authors declare no conflict of interest

Prevalence of drug-resistant <i>Pseudomonas aeruginosa</i> in Iranian burned patients: A meta-analysis

The increasing prevalence of drug-resistant Pseudomonas aeruginosa in burned patients is one of the main public health problems worldwide. Although drug-resistant P. aeruginosa in burn units is frequent in some countries and unusual in others, the level of this conditions is not precisely known in Iran. Imipenem is one of the most potent agents against P. aeruginosa. Imipenem resistance is a major obstacle to treatment of P. aeruginosa infections. We aimed to determine the true prevalence of imipenem-resistant P. aeruginosa in Iranian burned patients according to the Preferred Reporting Items for Meta-Analyses statement. Moreover, resistance to several potent anti-P. aerugi nosa drugs were indicated according to the Clinical and Laboratory Standards Institute guidelines for the disc diffusion method. Several databases including Web of Science, Scopus, PubMed, Scientific Information Database, Magiran, Iranmedex, and science direct were searched to get studies addressing drug-resistant P. aeruginosa in Iranian burned patients from March 2006 to May 2015. A total of 34 reports available from different areas of Iran were included in the current study. The meta-analyses showed that 54.9 of P. aeruginosa were resistant to imipenem. The most common resistance was seen against ceftazidime (66.9), followed by ciprofloxacin (52.9) and cefepime (52.3). It is necessary to know the epidemiology of drug-resistant P. aeruginosa because it can promote control strategies for decreasing their prevalence. The high incidence of drug-resistant P. aeruginosa in Iran emphasizes the need for precise drug susceptibility testing, continuous monitoring of drug resistance, especially in burn units, use of sensitive methods for the laboratory diagnosis, and close relation between physician and laboratories

Increasing the Power Production of Vertical-Axis Wind-Turbine Farms Using Synergistic Clustering

Vertical-axis wind turbines (VAWTs) are being reconsidered as a complementary technology to the more widely used horizontal-axis wind turbines (HAWTs) due to their unique suitability for offshore deployments. In addition, field experiments have confirmed that vertical-axis wind turbines can interact synergistically to enhance the total power production when placed in close proximity. Here, we use an actuator line model in a large-eddy simulation to test novel VAWT farm configurations that exploit these synergistic interactions. We first design clusters with three turbines each that preserve the omni-directionality of vertical-axis wind turbines, and optimize the distance between the clustered turbines. We then configure farms based on clusters, rather than individual turbines. The simulations confirm that vertical-axis wind turbines have a positive influence on each other when packed in well-designed clusters: such configurations increase the power generation of a single turbine by about 10 percent. In addition, the cluster designs allow for closer turbine spacing resulting in about three times the number of turbines for a given land area compared to conventional configurations. Therefore, both the turbine and wind-farm efficiencies are improved, leading to a significant increase in the density of power production per unit land area