Aysegul Atak

Diagnostic potential of serum direct markers and non-invasive fibrosis models in patients with chronic hepatitis B

Aim:  Liver biopsy is recommended in the majority of patients with chronic viral hepatitis for fibrosis evaluation. Because of the disadvantages of liver biopsy, many studies related to non‐invasive biomarkers and scores have been performed. In this study, we aimed to assess the diagnostic value of serum direct markers and non‐invasive fibrosis models to predict liver fibrosis in the treatment‐naive chronic hepatitis B (CHB) patients and to compare their diagnostic performance.

Evaluation of auricular lymph node cell lymphocyte proliferation and cytokine production as non-radioactive endpoints during murine contact allergy

The murine local lymph node assay (LLNA) has been developed as a test method to assess allergic contact dermatitis. In spite of the validity of the LLNA, attention was drawn to the two disadvantages: use of radioactivity for in vivo measurement of lymph node cell proliferation ([3H]-thymidine labeling) and the possibility of false positive results caused by non-specific cell activation as a result of inflammatory processes in the skin (irritation). We aimed to investigate the following non-radioactive endpoints of LLNA: 5-bromo-2′-deoxyuridine (BrdU) incorporation ex vivo and in vivo, in vivo and ex vivo cytokine production with or without phytohemagglutinin (PHA) stimulation. Here, 8-12-week-old female BALB/c mice were treated topically with the strong sensitizer 2,4-dinitrochlorobenzene (DNCB) in acetone:olive oil (AOO, 4:1 [v/v]) at levels of 0.025, 0.05, 0.01, or 0.25% (w/v). Ear thickness was also measured to determine the differentiation index (DI) indicating the proportion of non-specific activation due to irritating properties of test compound. At the concentration of 0.05%, stimulation index (SI) value was found to be 3 for DNCB based on in vivo and ex vivo BrdU incorporation. The results of the in vivo and ex vivo non-radioactive LLNA assays were compatible both with each other and with previous radioactive LLNA data. Our results indicate that non-radioactive endpoints may be used as an alternative to the [3H]-thymidine LLNA. The levels of TH1 cytokines (IL-2 and IFNγ) and TH2 cytokines (IL-4 and IL-5) in lymph node cell cultures were significantly (P < 0.01) increased when DNCB was applied at the concentrations of 0.05 and 0.1%, respectively. As the DI was > 1, the applied concentrations of DNCB caused only allergic effect but not any irritant effect. This study reports that the use of these non-radioactive endpoints can assess allergic contact dermatitis caused by chemicals.

Evaluation of non-radioactive endpoints of ex vivo local lymph node assay-BrdU to investigate select contact sensitizers.

The present study sought to verify the utility of the non-radioactive endpoints LLNA BrdU (5-bromo-2′-deoxyuridine) ex vivo incorporation and cytokine release using auricular lymph node cells isolated from BALB/c mice topically treated with a strong (formaldehyde or p-phenylene-diamine [PPD]), moderate sensitizer (cinnamal), or weak sensitizer (eugenol). Stimulation index (SI) and EC3 values were calculated for each agent. Based on the results of ex vivo LLNA-BrdU assays, EC3 values were calculated to be 0.29, 0.09, 1.91, and 16.60% for formaldehyde, PPD, cinnamal, and eugenol, respectively. These results were in good agreement with data from previous standard radioactive LLNA. Cytokine analyses indicated TH1 and TH2 cytokine involvement in the regulation of murine contact allergy and these could be utilized as endpoints in assessments of contact allergy in mice. In conclusion, the current study provided evidence that the non-radioactive endpoint LLNA BrdU ex vivo incorporation could be of use as a viable alternative approach to assess the skin sensitization potential of test compound with respect to improving animal welfare. This is of particular importance in the case of any laboratory where it might be difficult to handle and/or readily employ radioisotopes. Further studies will be required to confirm—across test agents—the reproducibility as well as the limits of utility of this new ex vivo BrdU method.

Development of Interleukin-2 Loaded Chitosan-Based Nanogels Using Artificial Neural Networks and Investigating the Effects on Wound Healing in Rats

ABSTRACTThe aim of this study was to develop and characterize rh- IL-2 loaded chitosan-based nanogels for the healing of wound incision in rats. Nanogels were prepared using chitosan and bovine serum albumin (BSA) by ionic gelation method and high temperature application, respectively. Particle size, zeta potential, and polydispersity index were measured for characterization of nanogels. The morphology of nanogels was examined by using SEM and AFM. The IL-2 loading capacity of nanogels was determined using ELISA method. In vitro release of IL-2 from nanogels was performed using Franz diffusion cells. Artificial neural network (ANN) models were developed using selected input parameters (stirring rate, chitosan%, BSA%, TPP%) where particle size was an output parameter for IL-2 free nanogels. Wound healing effect of IL-2 loaded chitosan-TPP nanogel was evaluated by determining the malondialdehyde (MDA) and glutathione (GSH) levels of wound tissues in rats. The particle size of IL-2 loaded chitosan-TPP nanogels was found to be larger than that of IL-2 loaded BSA-based chitosan nanogels. Drug loading capacity of nanogels was found 100% ± 0.010 for both nanogels. IL-2 was released slowly after the initial burst effect. According to SEM and AFM imaging, BSA-chitosan nanogel particles were of nanometer size and presented a swelling tendency, and chitosan-TPP nanogel particles were found to be spherical and homogenously dispersed. IL-2 loaded chitosan-TPP nanogel was found suitable for improving wound healing because it decreased the MDA levels and increased the GSH levels wound tissues comparing to control group.

Community-based research: cost of the tests used for anti-HBc total seropositivity only and hepatitis B screening.

Our study aimed to determine anti-HBc total (IgG+IgM) seroprevalence in the adult population aged ≥ 15 and to compare the cost of testing for HBsAg and anti-HBs in only anti-HBc positive+ subpopulation to that in the whole population for HBV screening. The study involved a face-to-face survey and peripheral blood sampling from 452 adult subjects for HBV tests. HBV-DNA PCR was studied only in anti-HBc+ subjects. Of the 452 subjects anti-HBc total was positive in 192 (42.47%), of which: (a) 27 (14.06%) were HBsAg+, anti-HBs negative⁻, (b) 126 (65.62%) were HBsAg⁻, anti-HBs+, (c) 39 were HBsAg⁻, anti-HBs⁻. This last group (c) were tested for HBV-DNA PCR and six (15.38%) were positive. When we perform HBsAg and anti-HBs tests in all 452 subjects as in routine practice in blood banks, the cost is 3320 Euros. However, when all subjects are tested for anti-HBc total at first and then only anti-HBc total+ ones are tested for HBsAg and anti-HBs, the cost is 2929 Euros. The cost difference between the two methods is 391 Euros for 452 subjects. Accordingly, our HBV screening algorithm brings a financial saving of 11.78% and helps to identify the isolated anti-HBc total+ subjects who carry potential risk for spreading HBV.

Evaluation of perinatal and intrafamilial hepatitis B prevention programmes in a well child clinic: 9-year follow-up study in Turkey.

Evaluating the performance of well child clinics on adherence to recommended perinatal hepatitis B prevention programmes as well as assessing the outcome of infants living with hepatitis B surface antigen (HBsAg)-positive parents is important. A retrospective study was performed of 336 babies who had at least one HBsAg-positive parent and were followed-up in the well child clinic of Gazi University Hospital (Ankara, Turkey) between 2001 and 2009. Rates of passive immunisation in 109 babies with HBsAg-positive mothers and initiation of hepatitis B vaccination of all 336 babies with HBsAg-positive parents were 98.8% and 100% respectively. Ninety-two babies (27.4%) were lost to follow-up before completing primary immunisation. The recommended perinatal hepatitis B prevention programme was performed successfully in 194 of the 306 infants who were old enough for post-vaccination serotesting (63.4%). One baby became HBsAg-positive, and 88.1% of babies were seroprotected. Hepatitis B surface antibody (anti-HBs) levels were found to be increased if the HBsAg-positive parent was the father. There was a negative correlation between serotesting time and anti-HBs titres. The study infants had a total of 187 siblings and 123 (65.8%) were serotested after completing primary immunisation with 108 found to be seropositive. Although the vaccination rate in the perinatal hepatitis B prevention programme is satisfactory, post-vaccination serotesting and evaluation of infants and their siblings are still deficient.