Cibacron blue F3GA incorporated immobilized metal chelate affinity sorbent as a high efficient affinity immobilization materials for catalase enzyme.

Catalase is a metalloenzyme commonly found in almost all plant and animal tissues and catalyzes the conversion of hydrogen peroxide to less reactive molecules. It is used for the elimination of hydrogen peroxide in biological, biomedical, food and textile applications. For this purpose, a novel affinity sorbent [poly(methacrylic acid- N-isopropyl acrylamide-CB-Fe3+, (p(MAA-NIPAAM)-CB-Fe3+)] for the determination and it was first developed using MAA and NIPAAM monomers. After characterization with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), adsorption parameters were determined. Reusability of p(MAA-NIPAAM)-CB-Fe3+ sorbent was determined after by determining the appropriate desorption agent for desorption of adsorbed catalase in the developed sorbent. It was determined that catalase adsorption could be performed with 0.01 g of sorbent in 45 min. The maximum adsorption capacity for catalase adsorption was determined as 243.17 mg/g with the use of sorbent. The operational and storage stability of the immobilized catalase was found to be high as expected. The conversion of H2O2 can be successfully performed by the immobilized enzyme in the prepared sorbent. It has been proven that the affinity of catalase for its substrate is increased by immobilization.

Are Symptoms Sufficient in the Decision to Start Antibiotics in Tonsillopharyngitis?

OBJECTIVES: Unnecessary use of antibiotics is one of the causes of antibiotic resistance. Rapid Antigen Test (RAT) is recommended to prevent unnecessary use of antibiotics by providing bacteria/virus isolation in patients with tonsillopharyngitis. However, in patients with typical symptoms, false-negative test results may lead to doubt in doctors. In this study, we aimed to evaluate the relationship between patients' symptoms and RAT results. METHODS: In this study, we chose the patients that referred to the University of Health Sciences (SBÜ) Sisli Hamidiye Etfal Training and Research Hospital Family Medicine Polyclinics and got a diagnosis of tonsillopharyngitis with RAT. This study was conducted by a retrospective file scanning method. We examined the age, sex, symptoms, RAT results and throat culture results of the patients. SPSS 15.0 for Windows program was used for the statistical analysis. The level of statistical significance was accepted as p<0.05. RESULTS: In this study, the RAT of 265 patients and the throat culture of 141 patients were examined. We found RAT positivity as 28.7%, Group A Beta Hemolytic Streptococcus (AGBHS) detection rate in throat culture was 22.5%, and the antibiotic prescription rate was 37%. There were 32 patients with AGBHS positivity in throat culture. Twenty-seven of them got RAT positivity, too. When symptoms and RAT positivity were examined, there was no significant relationship between RAT positivity and fever higher than 38 oC, but RAT was more often positive in patients with a fever higher than 38 oC. On the other hand, there is a statistically significant relationship between RAT positivity and the presence of tonsillar exudate (p=0.000). When the relationship between symptoms and RAT according to age groups was examined, the presence of LAP and tonsillitis were significant (p=0.000; p=0.001). In the age group of 18 years and over, the presence of tonsillar exudates was significant (p=0.001). CONCLUSION: In our study, tonsillar exudate was a common symptom in both age groups of <18, and ≥18 years of age; at the same time, there is a statistically significant relation with RAT. Tonsillar exudates are not seen only in bacterial infections but also in viral infections. Thus, we think that antibiotics should not be started based on symptoms, and RAT should be used effectively.

Vaccine rejection and hesitation in Turkey.

In Turkey, primary care staffs have observed an increased rate of vaccination refusal in recent years. The aim of the present study was to determine the prevalence of vaccination refusal and hesitancy in Turkey, in addition to the demographic features and underlying reasons. The present descriptive cross-sectional study was conducted in Istanbul and Tekirdag, two big Turkish cities that are exposed to widespread internal migration. To reflect Turkey's demographic structure, 1004 participants were selected using cluster sampling based on birthplace, age, and level of education, from all individuals who attended family medicine outpatient clinics at Namik Kemal University and Sisli Hamidiye Etfal Training and Research Hospital. A face-to-face questionnaire method was used. Data show that this decline was mainly the result of the increasing rate of vaccine rejection and hesitation, for which the most important reason was found to be distrust of vaccine companies. It can be concluded that individuals who display vaccine refusal and hesitation are mostly born in the developed geographical regions of Turkey and have high income and educational levels. According to these results, we anticipate that vaccination rates may fall in Turkey in the coming years.

Immunization rates of pneumococcal, influenza and tetanus vaccines and knowledge and attitudes of adult patients who receive inpatient treatment at hospital: Point prevalence study.

The safety of vaccines, access to health care, the level of community's knowledge and the attention of physicians play a critical role in the rate of adult vaccination. This study aims to determine the immunization rate of pneumococcal, influenza and tetanus vaccines among the patients and their knowledge and attitudes in the hospital. The study is a cross-sectional point prevalence survey. The patients who agreed to participate in the study were interviewed using a questionnaire. Patients' gender, occupation, educational status, income level and risk factors (immunosuppressed and over 65 years old) were compared with the knowledge and attitudes about vaccinations. Of the 251 participants, 51.4% were female and 48.6% were male. The self-reported vaccination rate was 3.5% for pneumococcal, 8.6% for influenza and 26.6% for tetanus. Most of the patients have knowledge about influenza vaccination (90.3%). Patients with the high education level have significantly higher knowlege about tetanus vaccination and higher rate of tetanus vaccine compared to those with low education level (p = 0.04; p = 0.006). It was found that those with higher income levels had the more pneumococcal vaccination, more knowledge on tetanus vaccination, and more attitude that tetanus vaccine is necessary compared to those with lower income level (p < 0.05). Patients without risk factors have a higher rate of tetanus vaccination compared to those with risk factors (p < 0.001). It was inferred that the high level of education and income have a positive effect on the patients vaccination rates and their knowledge and attitude.

Lab-on-a-chip based biosensor for the real-time detection of aflatoxin.

Polymers were synthesized and utilized for aflatoxin detection coupled with a novel lab-on-a-chip biosensor: MiSens and high performance liquid chromatography (HPLC). Non-imprinted polymers (NIPs) were preferred to be designed and used due to the toxic nature of aflatoxin template and also to avoid difficult clean-up protocols. Towards an innovative miniaturized automated system, a novel biochip has been designed that consists of 6 working electrodes (1mm diameter) with shared reference and counter electrodes. The aflatoxin detection has been achieved by a competition immunoassay that has been performed using the new biochips and the automated MiSens electrochemical biosensor device. For the assay, aflatoxin antibody has been captured on the Protein A immobilized electrode. Subsequently the sample and the enzyme-aflatoxin conjugate mixture has been injected to the electrode surfaces. The final injection of the enzyme substrate results in an amperometric signal. The sensor assays for aflatoxin B1 (AFB1) in different matrices were also performed using enzyme link immunosorbent assay (ELISA) and HPLC for confirmation. High recovery was successfully achieved in spiked wheat samples using NIP coupled HPLC and NIP coupled MiSens biosensor [2ppb of aflatoxin was determined as 1.86ppb (93% recovery), 1.73ppb (86.5% recovery), 1.96ppb (98% recovery) and 1.88ppb (94.0% recovery) for immunoaffinity column (IAC)-HPLC, NIP-HPLC, Supel™ Tox SPE Cartridges (SUP)-HPLC and NIP-MiSens, respectively]. Aflatoxin detection in fig samples were also investigated with MiSens biosensor and the results were compared with HPLC method. The new biosensor allows real-time and on-site detection of AFB1 in foods with a rapid, sensitive, fully automated and miniaturized system and expected to have an immense economic impact for food industry.

Microfluidics and nanoparticles based amperometric biosensor for the detection of cyanobacteria (Planktothrix agardhii NIVA-CYA 116) DNA.

Some of the cyanobacteria produce protease inhibitor oligopeptides such as cyanopeptolins and cause drinking water contamination; hence, their detection has great importance to monitor the well-being of water sources that is used for human consumption. In the current study, a fast and sensitive nucleic acid biosensor assay has been described where cyanopeptolin coding region of one of the cyanobacteria (Planktothrix agardhii NIVA-CYA 116) genome has been used as target for monitoring of the fresh water resources. A biochip that has two sets of Au electrode arrays, each consist of shared reference/counter electrodes and 3 working electrodes has been used for the assay. The biochip has been integrated to a microfluidics system and all steps of the assay have been performed during the reagent flow to achieve fast and sensitive DNA detection. On-line hybridization of the target on to the capture probe immobilized surface resulted in a very short assay duration with respect to the conventional static assays. The binding of the avidin and enzyme modified Au nanoparticles to the biotinylated detection probe and the subsequent injection of the substrate enabled a real-time amperometric measurement with a detection limit of 6×10(-12) M target DNA (calibration curve r(2)=0.98). The developed assay enables fast and sensitive detection of cyanopeptolin producing cyanobacteria from freshwater samples and hence shows a promising technology for toxic microorganism detection from environmental samples.

Fast and sensitive detection of mycotoxins in wheat using microfluidics based Real-time Electrochemical Profiling.

The objective of the study has been the development of a new sensing platform, called Real-time Electrochemical Profiling (REP) that relies on real-time electrochemical immunoassay detection. The proposed REP platform consists of new electrode arrays that are easy to fabricate, has a small imprint allowing microfluidic system integration, enables multiplexed amperometric measurements and performs well in terms of electrochemical immunoassay detection as shown through the deoxynivalenol detection assays. The deoxynivalenol detection has been conducted according to an optimised REP assay protocol using deoxynivalenol standards at varying concentrations and a standard curve was obtained (y=-20.33ln(x)+124.06; R(2)=0.97) with a limit of detection of 6.25 ng/ml. As both ELISA and REP detection methods use horse radish peroxidase as the label and 3.3',5.5'-Tetramethylbenzidine as the substrate, the performance of the REP platform as an ELISA reader has also been investigated and a perfect correlation between the deoxynivalenol concentration and the current response was obtained (y=-14.56ln(x)+101.02; R(2)=0.99). The calibration curves of both assays have been compared to conventional ELISA tests for confirmation. After assay optimisation using toxin spiked buffer, the deoxynivalenol detection assay has also been performed to detect toxins in wheat grain.