Aspergillus fumigatus Septic Arthritis of the Wrist: A Report of a Rare Case in an Immunocompromised Patient.

Aspergillus fumigatus is a saprophytic fungus encountered as a pathogen in airborne lung infections. Although it commonly causes pulmonary infectious diseases, when disseminated, it may cause a systemic infection termed invasive aspergillosis, which is associated with high mortality and morbidity. Virtually, all organ systems may be involved. However, the musculoskeletal system is relatively uncommon. Here, we present a case of invasive aspergillosis in an immunocompromised patient involving the wrist joint, an exceedingly rare site. Our treatment choice is serial open debridement, irrigation, and intravenous antibiotics. This case study exemplifies the potential challenges in the identification and treatment of such an uncommon clinical condition. A thorough clinical and microbiological evaluation is essential for accurate diagnosis of fungal septic arthritis of the wrist. Aggressive early surgical treatment combined with appropriate early intravenous antibiotics is crucial for eradicating joint infection.

Protein disulfide isomerase A3 might be involved in the regulation of 24-dehydrocholesterol reductase via vitamin D equilibrium in primary cortical neurons.

Vitamin D is a secosteroid hormone mediating its functions via vitamin D receptor (VDR) and an endoplasmic reticulum chaperone, protein disulfide isomerase A3 (PDIA3). From a physiological perspective, there is also a well-established association of cholesterol and vitamin D synthesis, since both share a common metabolic substrate, 7 dehydrocholesterol (7-DHC). Yet, the potential basic pathways, of the biological interplay of DHCR24 and vitamin D equilibrium, on neuronal level, are yet to be determined. In this study, we aimed to investigate the relation between vitamin D pathways and DHCR24 in primary cortical neuron cultures. The neocortex of Sprague-Dawley rat embryos (E16) was used for the preparation of primary cortical neuron cultures. DHCR24 mRNA and protein expression levels were determined by qRT-PCR, Western blotting, and immunofluorescent labeling in 1,25-dihydroxyvitamin D3-treated or VDR/PDIA3-silenced primary cortical neurons. The mRNA expression of DHCR24 was significantly decreased in the cortical neurons treated with 10-8M 1,25-dihydroxyvitamin D3 (p<0.001). In parallel with the mRNA results, DHCR24 protein expression in cortical neurons treated with 10-8M 1,25-dihydroxyvitamin D3 was also significantly lower than untreated neurons (p<0.05). These data were also confirmed with immunofluorescent labeling and fluorescence intensity measurements of DHCR24 (p<0.001). Finally, DHCR24 mRNA expression level was significantly increased in PDIA3 siRNA-treated neurons (p<0.05). Similar to the mRNA results, the DHCR24 protein expression of PDIA3 siRNA-treated neurons was also statistically higher than the other groups (p<0.05). Results of this mechanistic experimental basic study demonstrate that DHCR24 mRNA expression and protein concentrations attenuated in response to vitamin D treatment. Furthermore, we observed that PDIA3 might be involved in this modulatory effect. Our findings indicate a complex interaction of DHCR24 and vitamin D equilibrium, through the involvement of PDIA3 and vitamin D in the modulation of cholesterol metabolism in neuronal cells, requiring future studies on the field.