The Repurposing of Acetylsalicylic Acid as a Photosensitiser to Inactivate the Growth of Cryptococcal Cells

Photodynamic treatment (PDT) is often successful when used against aerobic microbes, given their natural susceptibility to oxidative damage. To this end, the current study aimed to explore the photodynamic action of acetylsalicylic acid (ASA; aspirin, which is commonly used to treat non-infectious ailments), when administered to respiring cryptococcal cells. The treatment of cryptococcal cells, i.e., exposure to 0.5 or 1 mM of ASA in the presence of ultraviolet light (UVL) for 10 min, resulted in a significant (p < 0.05) reduction in the growth of tested cells when compared to non-treated (non-Rx) cells, i.e., no ASA and no UVL. The treated cells were also characterised by diseased mitochondria, which is crucial for the survival of respiring cells, as observed by a significant (p < 0.05) loss of mitochondrial membrane potential (ΔΨM) and significant (p < 0.05) accumulation of reactive oxygen species (ROS) when compared to non-Rx cells. Moreover, the photolytic products of acetylsalicylic acid altered the ultrastructural appearance of treated cells as well as limited the expression levels of the capsular-associated gene, CAP64, when compared to non-Rx cells. The results of the study highlight the potential use of ASA as a photosensitiser that is effective for controlling the growth of cryptococcal cells. Potentially, this treatment can also be used as an adjuvant, to complement and support the usage of current anti-microbial agents.

Amyloidosis—Where Are We Now and Where Are We Heading?

Context.—Amyloidoses are disorders of diverse etiology in which deposits of abnormally folded proteins share distinctive staining properties and fibrillar ultrastructural appearance. Amyloidosis ultimately leads to destruction of tissues and progressive disease. With recent advances in the treatment of systemic amyloidoses the importance of an early diagnosis of amyloid, and a correct diagnosis of its type, has been realized. Objective.—To summarize current recommendations for the diagnosis of amyloidosis. Data Sources.—Presentation given at the 4th Annual Renal Pathology Society Satellite meeting in Istanbul based on discussions and recommendations formulated during an interactive diagnostic session held at the XIth International Symposium on Amyloidosis in Woods Hole, Massachusetts. Conclusions.—Congo red stain is currently the gold standard for amyloid detection and the goal is to detect amyloid early. Diagnosis of the amyloid type must be based on the identification of amyloid protein within the deposits and not solely by reliance on clinical or DNA studies. However, the latter are recommended for confirmation of the amyloid type based on evaluation of the protein in deposits. Immunohistochemistry must be performed and interpreted with caution and inconclusive results must be evaluated further using the more sophisticated methods available in referral centers. An adequate amount and quality of tissue must be available for amyloid diagnosis and typing with emphasis on the use of fresh tissue and greater use of abdominal fat biopsy. The development of new technologies underscores the need for regular review of recommendations and standards for the clinical diagnosis of amyloidosis.

Effect of Oxygenated Perfluorocarbons on Isolated Rat Pancreatic Islets in Culture

One impediment for a wider application of islet transplantation is the limited number of donor pancreata for islet isolation. A more efficient utilization of available organs could in part alleviate this problem. Perfluorocarbons (PFCs) have a high oxygen solubility coefficient and maintain high oxygen partial pressures for extended time. They serve also as oxygen “reservoirs” for harvested organs in pancreas organ transplantation. The aim of this study was to test whether the use of PFCs could also be beneficial for the secretory activity and overall viability of cultured purified islets before transplantation. Purified rat islets were cultured in static conditions with or without oxygen-saturated PFCs for 1 or 7 days. Cell death and apoptosis were assessed by trypan blue staining, DNA strand breaks, and caspase 3/7 activity. mRNA levels of insulin and ICA512/IA-2, a membrane marker of secretory granules (SGs), were quantitated by real-time PCR, whereas insulin content and secretion were measured by RIA. Polypyrimidine tract binding protein (PTB), which promotes SG biogenesis, was assessed by Western blotting. The number of SGs and the ultrastructural appearance of β-cells were analyzed by cryoimmunoelectronmicroscopy for insulin. Various parameters, including caspase activity, insulin and ICA512/IA-2 mRNA levels, PTB expression, number of secretory granules, and ultrastructural appearance did not significantly differ between control and PFC-cultured islets. On the other hand, PFC culture islets showed significantly increased DNA fragmentation and a reduced insulin stimulation index at both time points compared to control islets. While advantageous for the transport of human harvested organs, the use of PFH in the culture may be comparable to and/or not provide advantage over conventional protocols for culture of islets for transplantation.

Inflammatory interactions in fish exposed to pollutants and parasites: a role for apoptosis and C reactive protein

Although previous studies have highlighted the inflammatory responses of fish infected with parasites and exposed to pollutants, very little is known about how these two stressors interact within the fish. In this review, which also contains original data, the effect of these two parameters on the fish inflammatory response is assessed and, in particular, the role of apoptosis and the acute phase protein, C reactive protein, is evaluated. InCyprinus carpioexposed to 0·5 mg NH4+l−1or 0·1 mg Cd2+l−1and experimentally infected with the blood fluke,Sanguinicola inermis, the pollutant type and the order in which the fish experiences the parasite and toxicant, significantly affects the ultrastructural appearance and cellular content of the pronephros and thymus. This is reflected in the intensity of infection where the pollutant appears to have less effect on an established infection. Both stressors, pollutant and infection, may mediate their effects via the endocrine system. Studies have revealed that cortisol at 100 ng ml−1is able to induce apoptosis in pronephric cells of carp and that an increase in apoptosis is associated with an increase in phagocytosis in this immune organ. In addition, C reactive protein, which is used as a biomarker of the inflammatory response in humans and other mammals, is evaluated as a possible indicator of physiological states in fish exposed to pathogens and pollutants.

Macrophage functional maturation and cytokine production are impaired in C/EBPε-deficient mice

Members of the CCAAT/enhancer-binding protein (C/EBP) family are involved in the regulation of cellular differentiation and function of many tissues. Unlike the other members of the family, C/EBPε expression is restricted to granulocytes, macrophages, and lymphocytes. C/EBPε is highly conserved between human and rodents and is essential for terminal granulopoiesis in both species. To study the role that C/EBPε plays in macrophages, wild-type and C/EBPε–deficient (−/−) murine macrophages obtained from thioglycollate-elicited peritoneal lavages and differentiated bone marrow cells were compared. Although macrophage development occurred in both types of mice, the C/EBPε−/− cells had a lower expression of macrophage markers and a morphologic and ultrastructural appearance of immaturity. Phagocytic function, measured by calculating the percentage of internalized opsonized fluorescein isothiocyanate (FITC)–labeled yeast, was significantly impaired in the C/EBPε−/− macrophages compared with their wild-type counterparts. Furthermore, the differential expression of 26 macrophage-specific genes between wild-type and C/EBP−/− mice was analyzed. A subset of genes involved in differentiation, immune, and inflammatory responses was found down-regulated in the C/EBP−/− macrophages. Taken together, this study implicates theC/EBPε gene as an important transcription factor required for normal function and development of macrophages.