Usefulness of Discarded Vitreous Samples from Routine Vitrectomy

Purpose. To describe the histopathological features of vitreous samples obtained after vitrectomy surgery from diabetic and nondiabetic patients. Methods. Vitreous specimens from 137 patients who underwent vitrectomy for different clinical conditions were analysed. All samples were centrifuged and each resulting pellet was fixed and processed as part of routine paraffin section histopathology. The histopathological features were categorized in a semiquantitative fashion. The samples from diabetic and nondiabetic patients were compared. Results. The 125 included patients (58 diabetic, 60% males) were aged 64.2±13.9 years. The presence of hemorrhage, inflammatory cells, and histiocytes was significantly higher in the diabetic group (P<0.001, P=0.028, and P=0.016, resp.), showing more vessels (P<0.001) and ghost vessels (P=0.049). The presence of inflammatory cells was the feature with the highest sensitivity for detecting diabetes mellitus (98%) and also the highest negative predictive value (89%). In the multivariate analysis, three variables emerged as independent significant predictors of diabetes in vitrectomy samples: hemorrhage, endothelial-lined vessels, and age (P<0.001, P<0.001, and P=0.019, resp.). Conclusions. Different histopathological features can be found in vitreous samples from diabetic patients. Analysis of vitrectomy samples may serve as a tool for diabetes management

The effect of blue light exposure in an ocular melanoma animal model

<p>Abstract</p> <p>Background</p> <p>Uveal melanoma (UM) cell lines, when exposed to blue light in vitro, show a significant increase in proliferation. In order to determine if similar effects could be seen in vivo, we investigated the effect of blue light exposure in a xenograft animal model of UM.</p> <p>Methods</p> <p>Twenty New Zealand albino rabbits were injected with 1.0 × 10⁶human UM cells (92.1) in the suprachoroidal space of the right eye. Animals were equally divided into two groups; the experimental group was exposed to blue light, while the control group was protected from blue light exposure. The eyes were enucleated after sacrifice and the proliferation rates of the re-cultured tumor cells were assessed using a Sulforhodamine-B assay. Cells were re-cultured for 1 passage only in order to maintain any in vivo cellular changes. Furthermore, Proliferating Cell Nuclear Antigen (PCNA) protein expression was used to ascertain differences in cellular proliferation between both groups in formalin-fixed, paraffin-embedded eyes (FFPE).</p> <p>Results</p> <p>Blue light exposure led to a statistically significant increase in proliferation for cell lines derived from intraocular tumors (p < 0.01). PCNA expression was significantly higher in the FFPE blue light treated group when compared to controls (p = 0.0096).</p> <p>Conclusion</p> <p>There is an increasing amount of data suggesting that blue light exposure may influence the progression of UM. Our results support this notion and warrant further studies to evaluate the ability of blue light filtering lenses to slow disease progression in UM patients.</p

In vitro characterization and inhibition of the CXCR4/CXCL12 chemokine axis in human uveal melanoma cell lines

<p>Abstract</p> <p>Purpose</p> <p>The CXCR4/CXCL12 chemokine axis may play a critical role in guiding CXCR4+ circulating malignant cells to organ specific locations that actively secrete its ligand CXCL12 (SDF-1) such as bone, brain, liver, and lungs. We sought to characterize the presence of the CXCR4/CXCL12 axis in five uveal melanoma (UM) cell lines in vitro. The ability of TN14003, a synthetic peptide inhibitor that targets the CXCR4 receptor complex, to inhibit this axis was also assessed.</p> <p>Methods</p> <p>Immunocytochemistry was performed against CXCR4 to confirm expression of this chemokine receptor in all five UM cell lines. Flow cytometry was preformed to evaluate CXCR4 cell surface expression on all five UM cell lines. A proliferation assay was also used to test effects TN14003 would have on cellular proliferation. Inhibition of cellular migration by specifically inhibiting the CXCR4/CXCL12 axis with TN14003 was also investigated. The binding efficacy of TN14003 to the CXCR4 receptor was assessed through flow cytometric methods.</p> <p>Results</p> <p>The CXCR4 receptor was present on all five UM cell lines. All five cell lines expressed different relative levels of surface CXCR4. TN14003 did not affect the proliferation of the five cell lines (p > 0.05). All cell lines migrated towards the chemokine CXCL12 at a level greater than the negative control (p < 0.05). All 5 cell lines pre-incubated with TN14003 prevented cellular migration towards chemokine CXCL12 (p < 0.01). TN14003 preferentially binds CXCR4 to native ligand CXCL12.</p> <p>Conclusion</p> <p>Interfering with the CXCR4/CXCL12 axis, using TN14003 was shown to effectively down regulate UM cell migration in vitro. Knowing that UM expresses the CXCR4 receptor, these CXCR4+ cells may be less likely to colonize distant organs that secrete the CXCL12 ligand, if treated with an inhibitor that binds CXCR4. Further studies should be pursued in order to test TN14003 efficacy in vivo.</p

Cerrena unicolor growth and laccase biosynthesis in a submerged culture

Badano wzrost C. unicolor i biosyntezę lakazy w 15-litrowym reaktorze zbiornikowym. Wydzielanie enzymu rozpoczęło się w 60 h procesu, kiedy to zarówno glukoza jak i L-asparagina były obecne w podłożu. Stwierdzono, że produkcja enzymu była związana przede wszystkim z niedoborem tlenu rozpuszczonego w podłożu hodowlanym, co stanowi dla organizmu stres i skutkuje wydzieleniem zewnątrzkomórkowej lakazy.The growth of white-rot fungus C. unicolor and the synthesis of its secondary metabolite laccase in a 15 1 stirred bioreactor were investigated. Interestingly, laccase activity appeared at 60 h before glucose and L-asparagine were used up from the medium. This phenomenon was caused by oxygen limitation conditions which poses a stress for the organism, disturb the fungal metabolism and occurred advantageous to the enzyme formation

Laccase concentration by foam fractionation of Cerrena unicolor and Pleurotus sapidus culture supernatants

Foam fractionation process for concentration of laccases from two Basidiomycete strains under different process conditions was investigated. Culture supernatants of Cerrena unicolor and Pleurotus sapidus containing active laccase were used with and without surfactant additives. Two surfactants: cationic cetrimonium bromide (CTAB) and non-ionic Polysorbate 80 were applied in the range from 0.2 mM to 1.5 mM. The pH levels ranging from 3 to 10 were examined with particular attention to pH=4, which is close to the pI of the enzymes. Results show that the source of the enzyme is significant in terms of partitioning efficiency in a foam fractionation process. Laccase from Cerrena unicolor showed the best activity partitioning coefficients between foamate and retentate of almost 200 with yields reaching 50% for pH 7.5 and concentration of CTAB cCTAB = 0.5 mM, whereas laccase from Pleurotus sapidus showed partitioning coefficients of up to 8 with 25% yield for pH 4 and cCTAB = 0.5 mM

Application of foam fractionation process for concentartion of laccase from Cerrena unicolor

Przeprowadzono badania dotyczące frakcjonowania pianowego lakazy z płynu pohodowlanego szczepu Cerrena unicolor. Zbadano wpływ pH oraz dodatku bromku cetylotrimetyloamoniowego na podział międzyfazowy enzymu oraz na jego odzysk w kondensacie piany, jak również zmiany w efektywności przenoszenia lakazy do fazy pianowej w równych odstępach czasowych. Optymalne warunki osiągnięto w pH 4. Dodatek detergentu w zakresie 0,4÷1,0 mM zwiększał zarówno współczynnik podziału aktywności jak i odzysk w kondensacie piany. Szybkość przenoszenia enzymu w czasie była stała.Experiments regarding foam fractionation of laccase from culture supernatant of Cerrena unicolor strain were conducted. Influences of pH value and cetrimonium bromide addition on partitioning coefficient and yields in the foamate were investigated. Additionally, changes in effectiveness of laccase transport toward foam over time weremeasured. The optimum pH for the process was equal to 4.0.The detergent addition increased values of partitioning coefficients and yields in the foamate. The rate of enzyme transport toward foam was constant

Biosynthesis of laccase in the presence of aluminium oxide particles in a medium

W pracy przedstawiono badania wpływu obecności mineralnych cząstek tlenku glinu w podłożu hodowlanym na morfologię grzybni i produkcję lakazy przez Cerrena unicolor. Dodatek mikrocząstek powodował wzrost aktywności lakazy we wszystkich badanych stężeniach. Z praktycznego punktu widzenia stężenie tlenku glinu 15 g/dm3 uznano za wartość optymalną ze względu na wysoki poziom aktywności oraz całkowite wbudowanie tlenku glinu. Wzrost stężenia tlenku glinu powodował zmniejszenie wielkości peletek, ich powierzchnia stawała się silniej owłosiona aż do uzyskania grzybni rozproszonej przy stężeniu 30g/dm3.The influence of aluminium oxide particles in the culture medium on laccase biosynthesis and fungal morphology was studied. The results show the positive effect of microparticles at all tested concentrations of aluminium oxide. The concentration of 15 g/l was selected as the optimal one because of high laccase activity and complete incorporation of aluminium oxide to biomass. The higher concentration of aluminium oxide caused the decrease in pellets size and their surfaces got more hairy up to transformation into dispersed morphology at the concentration of 30 g/l