ABSTRACT
Methods@#For simulating BRONJ, zoledronic acid was administered to 40 rats for 5 weeks. Two weeks later, a right first molar was extracted from each rat. The rats were randomized into four groups of socket treatments: control (empty extraction socket) or with sockets filled with ACS, HA, or HA+ACS (n=4×10). After 2 weeks, 5 rats in each group were sacrificed and subjected to histopathologic and histomorphometric evaluation. Eight weeks post-surgically, the rest of rats were euthanized and histologically examined. The Kruskal-Wallis test was used to compare the four treatments at each time point (α=0.05). @*Results@#Six rats were lost overall. In the second week, vascularization was higher in ACS group (P0.05); empty lacunae were the most and fewest in control and HA+ACS groups, respectively (P0.05). In the eighth week, vascularization was not different in groups (P>0.05); the highest and lowest osteoclast activities were seen in the control and HA+ACS groups, respectively (P<0.05); empty lacunae were the most and fewest in control and HA+ACS, respectively (P<0.05); maximum and minimum numbers of eosinophils were in control and HA+ACS groups, respectively (P<0.05); HA and control groups exhibited the highest and lowest lymphocyte counts, respectively (P<0.05); the lowest and highest neutrophil counts were observed in HA+ACs and control groups, respectively (P<0.05); and the highest and lowest extents of the live bone were observed in HA+ACS and control groups, respectively (P<0.05). @*Conclusions@#Within the limitations of this preliminary animal study, HA and especially HA+ACS seem a proper method for preventing or treating BRONJ.
ABSTRACT
Background: Amongst the methods that remove heavy metals from environment, biosorption approaches have received increased attention because of their environmentally friendly and cost-effective feature, as well as their superior performances
Methods: In the present study, we investigated the ability of a surface-engineered Escherichia coli, carrying the cyanobacterial metallothionein on the cell surface, in the removal of Ca [II] from solution under different experimental conditions. The biosorption process was optimized using central composite design. In parallel, the kinetics of metal biosorption was studied, and the rate constants of different kinetic models were calculated
Results: Cadmium biosorption is followed by the second-order kinetics. Freundlich and Langmuir equations were used to analyze sorption data; characteristic parameters were determined for each adsorption isotherm. The biosorption process was optimized using the central composite design. The optimal cadmium sorption capacity [284.69 nmol/mg biomass] was obtained at 40[degree]C [pH 8] and a biomass dosage of 10 mg. The influence of two elutants, EDTA and CaCl[2], was also assessed on metal recovery. Approximately, 68.58% and 56.54% of the adsorbed cadmium were removed by EDTA and CaCl[2] during desorption, respectively. The Fourier transform infrared spectrophotometer [FTIR] analysis indicated that carboxyl, amino, phosphoryl, thiol, and hydroxyl are the main chemical groups involved in the cadmium bioadsorption process
Conclusion: Results from this study implied that chemical adsorption on the heterogeneous surface of E. coli E and optimization of adsorption parameters provides a highly efficient bioadsorbent
ABSTRACT
Identification and use of more efficient enzymes in the food and pharmaceutical industries is the focus of many researchers. The aim of this study was to search for a new bacterial strain capable of producing high levels of pullulanase applicable to biotechnology, the starch bioprocessing and food industries. A new pullulan hydrolyzing Bacillus strain was isolated and designated SDK2. Morphological and biochemical tests identified the strain as a putative Bacillus cereus strain, which was further characterized and confirmed through 16s rRNA sequencing, and was submitted to GeneBank, under the accession number FR6864500. Quantative analysis of the strain's pullulanase activity was carried out by the Dintrosalicyclic [DNS] acid-based assay. Thin layer chromatography [TLC] of the culture supernatant, identified the extracellular pullulanase as neopullulanase. Effects of temperature and pH on pullulanase activity were also studied. The optimum conditions for enzyme activity, as represented by 60°C and a pH of 7, resulted in an activity of 13.43 U/ml, which is much higher than some of the previously reported activities. However, growth of B. cereus SDK2 was also observed at a pH range of 5 to 10, and temperatures of 30°C to 50°C. The effect of metal ions and reagents, such as Mg[+2], Ca[+2], Zn[+2], Cu[+2], Fe[+2], Ni[+2] on enzyme activity showed that Ca[+2] ions increased pullulan activity, whereas the other ions and reagents inhibited pullulanase activity. The ability of B. cereus SDK2 to produce high levels of neopullulanase stable at 60°C that can generate panose from pullulan, make this newly isolated strain a valuable source of debranching enzyme for biotechnology, the starch bioprocess and medical industries