Production of galactooligosaccharides using various combinations of the commercial ß-galactosidases.

Galactooligosaccharides (GOS) are currently attracting considerable interest as prebiotic substances and can be prepared by transgalactosylation reactions from lactose using ß-galactosidase. We applied various combinations of the commercial ß-galactosidases, such as Nola Fit 5500, Saphera 2600 L, Maxilact LGI 5000 and Maxilact A4 MG to achieve the highest yield of GOS and reduced lactose content. The combination of the Maxilact LGI 5000 and Nola Fit 5500 resulted in amount of GOS 105 g L-1 with lactose content lower than 5 g L-1, whilst the combination of the Maxilact A4 MG and Maxilact LGI 5000 enzymes led to an increase in GOS to 141,1 g L-1 and decrease of the lactose content to 46,9 g L-1. The combination of enzymes produced a higher yield of GOS, reduced the concentration of lactose, eventually, increases the efficiency of galactooligosaccharides purification that could be potentially used in the further investigations.

Pulmonary imaging using dual-energy CT, a role of the assessment of iodine and air distribution.

AIM: The aim of the study is to present the feasibility of using dual-energy CT and the evaluation of iodine and air distribution in differentiation of pathological conditions. MATERIAL AND METHOD: We used the data of 50 CT examinations performed due to suspected pulmonary embolism with any pathological finding except consolidation of the parenchyma. The patients underwent CT angiography of the pulmonary arteries on a dual-source CT (DSCT), with the two tubes independently operated at 140 and 80 kV. By exploiting the dual-energy information, iodine distribution maps were obtained in addition to the conventional CT images which served as a marker of pulmonary perfusion. Minimum intensity projections (MinIP) were used as a marker of air content. RESULTS: By comparing the iodine distribution maps and MinIP images, it was possible to differentiate between the following templates of lung parenchyma: A--normal iodine and air distribution; B--iodine content deficit with minimal or with no redistribution of air; C--reduced iodine content and increased content of air; D--deficit of iodine content and increased content of air; E--increased iodine content and normal content of air; F--increased iodine content and reduced content of air; G--reduced perfusion and reduced content of air. The type A (five cases) was typical for the pulmonary embolism with preserved normal conditions of perfusion and ventilation. Type B (18 cases) occurred in pulmonary embolism; type C was found in case of inflammation of small respiratory airways (five cases); emphysema was typical for type D (nine cases); increased perfusion was observed in the parenchyma preserved from emphysema or preserved from embolism in cases of emphysema or pulmonary embolism; type F occurred in pulmonary interstitial edema (four cases) both with pulmonary infection; finally type G was found in interstitial lung diseases (five cases). CONCLUSION: Imaging of the pulmonary circulation by means of dual-energy CT opens the potential to study pathological changes of circulatory and pulmonary perfusion impairments, our presented work signs the important relations between iodine and air distribution which have to be thought in the interpretation of dual-energy perfusion imaging of the lungs.

The assessment of intracranial bleeding with virtual unenhanced imaging by means of dual-energy CT angiography.

The purpose of this study was to assess virtual unenhanced brain computed tomography (CT) images obtained by dual-energy CT angiography (CTA) for the detection of intracranial bleeding. In total, 25 patients were included in the study (average age 53.2 years, range 25-75 years, 14 male, 11 female), all with intracranial bleeding on unenhanced brain CT and who underwent additional CTA performed on a dual-source CT in a dual-energy acquisition mode. The two X-ray tubes were operated at 140 and 80 kV, respectively. Data were analyzed using dual-energy evaluation software. Virtual unenhanced images were calculated by removing the relative iodine content from each voxel. The virtual unenhanced images were evaluated by a radiologist blinded to the findings of the conventional images related to the presence of intracranial bleeding. The image quality and contrast-to-noise ratio (CNR) between bleeding and brain tissue were assessed. The virtual image quality was found to be sufficient in 96%. The agreement in detection of intracranial bleeding on virtual and conventional unenhanced images reached 96% in per-lesion analysis and 100% in per-patient analysis. The averaged CNR reached 2.63 in virtual unenhanced images and 3.27 in conventional. Virtual unenhanced images are sufficient for the detection of intracranial bleeding.